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.

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.

Teeth segmentation of dental periapical radiographs based on local singularity analysis

Teeth segmentation for periapical raidographs is one of the most critical tasks for effective periapical lesion or periodontitis detection, as both types of anomalies usually occur around tooth boundaries and dental radiographs are often subject to noise, low contrast, and uneven illumination. In this paper, we propose an effective scheme to segment each tooth in periapical radiographs. The method consists of four stages: image enhancement using adaptive power law transformation, local singularity analysis using Hölder exponent, tooth recognition using Otsu's thresholding and connected component analysis, and tooth delineation using snake boundary tracking and morphological operations. Experimental results of 28 periapical radiographs containing 106 teeth in total and 75 useful for dental examination demonstrate that 105 teeth are successfully isolated and segmented, and the overall mean segmentation accuracy of all 75 useful teeth in terms of (TP, FP) is (0.8959, 0.0093) with standard deviation (0.0737, 0.0096), respectively.

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.

Improvement of hepatocyte recovery from rat liver subjected to 1-hour warm ischemic injury by using citrate phosphate dextrose added to euro-collins perfusion solution

Warm ischemia (WI)-related injury interferes with recovery of primary hepatocyte after collagenase digestion of surgically resected or non-heart-beating donor livers as human cell sources. We speculated that digestion is impaired due to reduced microcirculation, caused by microembolism after WI. We sought to improve hepatocyte recovery after WI using a rat model. Anesthetized 9-week-old male Sprague-Dawley rats underwent a midline abdominal incision to insert a 22-gauge cannula into the portal vein. WI was initiated by ligating both the cannula and the hepatic artery. We compared Euro-Collins (EC) perfusion solution with 2 anticoagulants-heparin or citrate phosphate dextrose (CPD)-versus ethylene glycol tetraacetic acid (EGTA) combined with Ca(2+)- and Mg(2+)-free Hank's solution (CM-free Hank's solution). Use of CM-free Hank's solution yielded only 0.75 ± 0.15 × 10(8) and 0.82 ± 0.20 × 10(8) cells at 30 and 60 minutes WI respectively. However, CPD, but not heparin, added to the EC solution produced the best cell recovery (CPD: 2.15 ± 0.38 × 10(8); heparin: 1.63 ± 0.31 × 10(8)). During macroscopic observation, CPD added to EC solution also demonstrated best blood flushing. CPD added to EC solution achieved greater hepatocyte recovery than CM-free Hank's solution by restoring microcirculation during flushing of blood from liver tissue subjected to WI.

Hematologic responses in patients with aplastic anemia treated with deferasirox: a post hoc analysis from the EPIC study

Reports are emerging of hematologic responses associated with iron chelation therapy; however, studies are limited in aplastic anemia patients. Deferasirox reduced iron overload in aplastic anemia patients enrolled in the EPIC (Evaluation of Patients' Iron Chelation with Exjade(®)) study (n=116). A post hoc analysis of hematologic responses was conducted on 72 patients with evaluable hematologic parameters (according to UK guideline criteria), 24 of whom received deferasirox without concomitant immunosuppressive treatment. Partial hematologic responses were observed in 11 of 24 (45.8%) patients; all became transfusion-independent. One patient had an additional platelet response and one patient had an additional platelet and hemoglobin response. Mean serum ferritin levels at end of study were significantly reduced in partial hematologic responders (n=11; -3948 ± 4998 ng/mL; baseline 6693 ± 7014 ng/mL; percentage change from baseline -45.7%; P=0.0029). In non-responders, the reduction in serum ferritin was less pronounced (n=13; -2021 ± 3242 ng/mL; baseline 4365 ± 3063 ng/mL; % change from baseline -27.6%; P=0.0171). Alongside reduction in iron overload, deferasirox may, therefore, improve hematologic parameters in a subset of aplastic anemia patients. Further investigation is required to elucidate the mechanisms involved.

Validation of the behavior and concept based assessment of professionalism competence in postgraduate first-year residents

BACKGROUND

The evaluation of professional behaviors and concepts of postgraduate first-year (PGY1) residents has been identified as an area for development. This study examined the efficiency of the professionalism-assessing objective structured clinical examination (OSCE), 360° evaluation, and mini-Clinical Examination Exercise scores (mini-CEX; p-OSCE, p-360° evaluation, and p-mini-CEX scores).

METHODS

Between January 2009 and January 2012, 189 PGY1 residents were evaluated for behavior- and concept-based professionalism competence based on the above three methods using two checklists unique to each case. Data were analyzed for reliability, inter-rater agreement, interval changes, and gender-related difference for each method.

RESULTS

The test reliabilities of p-OSCE, p-360° evaluation, and p-mini-CEX were acceptable. Further, the reliability of concept and combined p-OSCE was higher than that of behavior p-OSCE. In addition, the concept OSCE p-scores and behavior 360° evaluation p-scores were significantly improved after 6 months of training. The inter-rater agreements were relatively good in p-OSCE and p-360° evaluation. Interestingly, male PGY1 residents had higher behavior 360° evaluation p-scores from nurses than those of females, whereas female PGY1 residents had higher behavior 360° evaluation p-scores from patients than those of males. Behavior and concept OSCE p-scores were positively correlated with behavior 360° evaluation p-scores. In comparison with p-360° evaluation, the combination of p-360° evaluation + OSCE + mini-CEX significantly increases their reliabilities.

CONCLUSION

The current study suggests that the p-OSCE, p-360° evaluation, and p-mini-CEX are feasible methods for evaluating professionalism in clinical training of PGY1 residents. Combination of the above three evaluations, participation, and support from multiple constituencies and multiple representatives provides good reliability and adds credibility in the assessment of professionalism competence.

Annexin A1 mediates the anti-inflammatory effects during the granulocytic differentiation process in all-trans retinoic acid-treated acute promyelocytic leukemic cells (63.2)

Annexin A1 (AnxA1) originating from neutrophils and their microparticles (MPs) plays an important anti-inflammatory role. The role of AnxA1 during the process of granulocytic differentiation is still unknown. All-trans retinoic acid (ATRA) can induce differentiation of acute promyelocytic leukemic(APL) cells into mature granulocytes. We investigated whether or not AnxA1 contributed to the anti-inflammatory properties of ATRA-treated APL (NB4; ATRA-NB) cells. We found that ATRA was able to enhance the surface expression of AnxA1 and its receptor (FPR2/ALX) and the release of AnxA1-containing MPs from ATRA-NB4 cells. Further studies demonstrated that exogenous AnxA1 could inhibit ATRA-NB4 cells in their transmigratory and adhesive activity. In addition, the transmigratory activity of ATRA-NB4 cells can be significantly enhanced by pretreatment with a FPR2/ALX neutralizing antibody, suggesting that endogenous AnxA1 may contribute to the anti-migratory effects. Finally, ATRA-NB4-derived MPs could also inhibit recipient cells in their transmigratory and adhesive activities and these anti-inflammatory effects could be inhibited by pretreatment of MPs with an anti-AnxA1 antibody. Further studies demonstrated that FITC-labeled AnxA1 could be transport from MPs to the membrane of recipient ATRA-NB4 cells. We conclude that biologically active AnxA1 may play a role in the anti-inflammatory properties of ATRA-APL cells during the process of granulocytic differentiation.

A nation-wide analysis of venous thromboembolism in 497,180 cancer patients with the development and validation of a risk-stratification scoring system

The Asian population is thought to have a low risk of venous thromboembolism (VTE), but the epidemiology of VTE in cancer patients remains unclear. The National Health Insurance Research Database of Taiwan was used to find hospitalised patients newly-diagnosed with cancer to determine the incidence of VTE in cancer patients and to identify the risk factors for VTE. Between 1997 and 2005, 497,180 cancer patients were identified. During a median follow-up of 21.3 months (range 0-119.9 months), 5,296 patients developed VTE. The estimated incidence was 185 events per 100,000 person-years. Patients with a prior history of VTE and female patients between the ages of 40 and 80 carried high risk of VTE. The rate of VTE was relatively high in patients with myeloma, prostate cancer, lung cancer, gynaecologic cancers, sarcoma, and metastasis of unknown origin. We developed a risk-stratification scoring system to divide the cancer patients into four discrete risk groups (very low risk, low risk, intermediate, and high risk). The incidence of VTE in each group was 0.5%, 0.9%, 1.5%, and 8.7%, respectively (p < 0.001). This scoring system was validated in a separate patient cohort. In conclusion, VTE is a distinct burden for cancer patients in Taiwan. The risk scoring system could prove helpful in decision-making concerning thromboprophylaxis in cancer patients.

Assessment of first-year post-graduate residents: usefulness of multiple tools

BACKGROUND

Objective Structural Clinical Examination (OSCE) usually needs a large number of stations with long test time, which usually exceeds the resources available in a medical center. We aimed to determine the reliability of a combination of Direct Observation of Procedural Skills (DOPS), Internal Medicine in-Training Examination (IM-ITE(®)) and OSCE, and to verify the correlation between the small-scale OSCE+DOPS+IM-ITE(®)-composited scores and 360-degree evaluation scores of first year post-graduate (PGY(1)) residents.

METHODS

Between 2007 January to 2010 January, two hundred and nine internal medicine PGY1 residents completed DOPS, IM-ITE(®) and small-scale OSCE at our hospital. Faculty members completed 12-item 360-degree evaluation for each of the PGY(1) residents regularly.

RESULTS

The small-scale OSCE scores correlated well with the 360-degree evaluation scores (r = 0.37, p < 0.021). Interestingly, the addition of DOPS scores to small-scale OSCE scores [small-scale OSCE+DOPS-composited scores] increased it's correlation with 360-degree evaluation scores of PGY(1) residents (r = 0.72, p < 0.036). Further, combination of IM-ITE(®) score with small-scale OSCE+DOPS scores [small-scale OSCE+DOPS+IM-ITE(®)-composited scores] markedly enhanced their correlation with 360-degree evaluation scores (r = 0.85, p < 0.016).

CONCLUSION

The strong correlations between 360-degree evaluation and small-scale OSCE+DOPS+IM-ITE(®)-composited scores suggested that both methods were measuring the same quality. Our results showed that the small-scale OSCE, when associated with both the DOPS and IM-ITE(®), could be an important assessment method for PGY(1) residents.

A core competence-based objective structured clinical examination (OSCE) in evaluation of clinical performance of postgraduate year-1 (PGY₁) residents

BACKGROUND

Clinical competency certifications are important parts of internal medicine residency training. This study aims to evaluate a composite objective structured clinical examination (OSCE) that assesses postgraduate year-1 (PGY(1)) residents' acquisition of the six core competencies defined by the Accreditation council for Graduate Medical Education (ACGME).

METHODS

Six-core-competency-based OSCE was used as examination of the clinical performance of 192 PGY(1) residents during their 3-month internal medicine training between 2007 January and 2009 December. For each year, the reliability of the entire examination was calculated with Cronbach's alpha.

RESULTS

The reliability of six-core-competency-based OSCE was acceptable, ranging from 0.69 to 0.87 between 2007 and 2009. In comparison with baseline scores, the summary scores and core-competency subscores all showed significant increase after PGY(1) residents finished their 3-month internal medicine training program.

CONCLUSION

By using a structured development process, the authors were able to create reliable evaluation items for determining PGY(1) residents' acquisition of the ACGME core competencies.

Correlation of microarray-based breast cancer molecular subtypes and clinical outcomes: implications for treatment optimization

Background

Optimizing treatment through microarray-based molecular subtyping is a promising method to address the problem of heterogeneity in breast cancer; however, current application is restricted to prediction of distant recurrence risk. This study investigated whether breast cancer molecular subtyping according to its global intrinsic biology could be used for treatment customization.

Methods

Gene expression profiling was conducted on fresh frozen breast cancer tissue collected from 327 patients in conjunction with thoroughly documented clinical data. A method of molecular subtyping based on 783 probe-sets was established and validated. Statistical analysis was performed to correlate molecular subtypes with survival outcome and adjuvant chemotherapy regimens. Heterogeneity of molecular subtypes within groups sharing the same distant recurrence risk predicted by genes of the Oncotype and MammaPrint predictors was studied.

Results

We identified six molecular subtypes of breast cancer demonstrating distinctive molecular and clinical characteristics. These six subtypes showed similarities and significant differences from the Perou-Sørlie intrinsic types. Subtype I breast cancer was in concordance with chemosensitive basal-like intrinsic type. Adjuvant chemotherapy of lower intensity with CMF yielded survival outcome similar to those of CAF in this subtype. Subtype IV breast cancer was positive for ER with a full-range expression of HER2, responding poorly to CMF; however, this subtype showed excellent survival when treated with CAF. Reduced expression of a gene associated with methotrexate sensitivity in subtype IV was the likely reason for poor response to methotrexate. All subtype V breast cancer was positive for ER and had excellent long-term survival with hormonal therapy alone following surgery and/or radiation therapy. Adjuvant chemotherapy did not provide any survival benefit in early stages of subtype V patients. Subtype V was consistent with a unique subset of luminal A intrinsic type. When molecular subtypes were correlated with recurrence risk predicted by genes of Oncotype and MammaPrint predictors, a significant degree of heterogeneity within the same risk group was noted. This heterogeneity was distributed over several subtypes, suggesting that patients in the same risk groups require different treatment approaches.

Conclusions

Our results indicate that the molecular subtypes established in this study can be utilized for customization of breast cancer treatment.

Blockade of JAK2 activity suppressed accumulation of β-catenin in leukemic cells

The Wnt/β-catenin pathway has been implicated in leukemogenesis. We found β-catenin abnormally accumulated in both human acute T cell leukemia Jurkat cells and human erythroleukemia HEL cells. β-Catenin can be significantly down-regulated by the Janus kinase 2 specific inhibitor AG490 in these two cells. AG490 also reduces the luciferase activity of a reporter plasmid driven by LEF/β-catenin promoter. Similar results were observed in HEL cells infected with lentivirus containing shRNA against JAK2 gene. After treatment with 50 µM AG490 or shRNA, the mRNA expression levels of β-catenin, APC, Axin, β-Trcp, GSK3α, and GSK3β were up-regulated within 12-16 h. However, only the protein levels of GSK3β and β-Trcp were found to have increased relative to untreated cells. Knockdown experiments revealed that the AG490-induced inhibition of β-catenin can be attenuated by shRNA targeting β-TrCP. Taken together; these results suggest that β-Trcp plays a key role in the cross-talk between JAK/STAT and Wnt/β-catenin signaling in leukemia cells.

Clinical instructors' perception of a faculty development programme promoting postgraduate year-1 (PGY1) residents' ACGME six core competencies: a 2-year study

Objective The six core competencies designated by Accreditation Council for Graduate Medical Education (ACGME) are essential for establishing a patient centre holistic medical system. The authors developed a faculty programme to promote the postgraduate year 1 (PGY(1)) resident, ACGME six core competencies. The study aims to assess the clinical instructors' perception, attitudes and subjective impression towards the various sessions of the 'faculty development programme for teaching ACGME competencies.' Methods During 2009 and 2010, 134 clinical instructors participated in the programme to establish their ability to teach and assess PGY(1) residents about ACGME competencies. Results The participants in the faculty development programme reported that the skills most often used while teaching were learnt during circuit and itinerant bedside, physical examination teaching, mini-clinical evaluation exercise (mini-CEX) evaluation demonstration, training workshop and videotapes of 'how to teach ACGME competencies.' Participants reported that circuit bedside teaching and mini-CEX evaluation demonstrations helped them in the interpersonal and communication skills domain, and that the itinerant teaching demonstrations helped them in the professionalism domain, while physical examination teaching and mini-CEX evaluation demonstrations helped them in the patients' care domain. Both the training workshop and videotape session increase familiarity with teaching and assessing skills. Participants who applied the skills learnt from the faculty development programme the most in their teaching and assessment came from internal medicine departments, were young attending physician and had experience as PGY(1) clinical instructors. Conclusions According to the clinical instructors' response, our faculty development programme effectively increased their familiarity with various teaching and assessment skills needed to teach PGY(1) residents and ACGME competencies, and these clinical instructors also then subsequently apply these skills.

Chronic hepatitis virus infection in patients with multiple myeloma: clinical characteristics and outcomes

OBJECTIVES

Cytotoxic agents and steroids are used to treat lymphoid malignancies, but these compounds may exacerbate chronic viral hepatitis. For patients with multiple myeloma, the impact of preexisting hepatitis virus infection is unclear. The aim of this study is to explore the characteristics and outcomes of myeloma patients with chronic hepatitis virus infection.

METHODS

From 2003 to 2008, 155 myeloma patients were examined to determine their chronic hepatitis virus infection statuses using serologic tests for the hepatitis B (HBV) and C viruses (HCV). Clinical parameters and outcome variables were retrieved via a medical chart review.

RESULTS

The estimated prevalences of chronic HBV and HCV infections were 11.0% (n = 17) and 9.0% (n = 14), respectively. The characteristics of patients who were hepatitis virus carriers and those who were not were similar. However, carrier patients had a higher prevalence of conventional cytogenetic abnormalities (64.3% vs. 25.0%). The cumulative incidences of grade 3-4 elevation of the level of alanine transaminase, 30.0% vs. 12.0%, and hyperbilirubinemia, 20.0% vs. 1.6%, were higher in carriers as well. In a Kaplan-Meier analysis, carrier patients had worse overall survival (median: 16.0 vs. 42.4 months). The prognostic value of carrier status was not statistically significant in the multivariate analysis, but an age of more than 65 years old, the presence of cytogenetic abnormalities, a beta-2-microglobulin level of more than 3.5 mg/L, and a serum creatinine level of more than 2 mg/ dL were independent factors associated with poor prognosis.

CONCLUSION

Myeloma patients with chronic hepatitis virus infections might be a distinct subgroup, and close monitoring of hepatic adverse events should be mandatory.

Prevalence of MPL W515L/K mutations in Taiwanese patients with Philadelphia-negative chronic myeloproliferative neoplasms

BACKGROUND

The discovery of Janus kinase 2 (JAK2)-V617F has provided important insight into the pathogenesis of Philadelphia-negative chronic myeloproliferative neoplasms (Ph-negative MPNs); however, the etiology of JAK2(V617F)-negative Ph-negative MPN remains unidentified. MPL(W515L) and MPL(W515K) (MPL(W515L/K)) are 2 gain-of-function mutations, which have been found in some Ph-negative MPN patients from Western countries. However, little is known about the incidence of these mutations in Taiwanese Ph-negative MPN patients.

METHODS

We determined the MPL sequence of DNA samples from 105 patients, including 88 patients with Ph-negative MPNs and 17 with myelodysplastic syndrome, using polymerase chain reaction amplification of the cytokine receptor MPL exon 10 sequence.

RESULTS

All the patients were normal at codon 515 regardless of their JAK2 status.

CONCLUSION

The MPL W515L/K mutations are rare in Taiwanese patients with Ph-negative MPNs.

High early mortality rate in elderly patients with multiple myeloma receiving a vincristine-doxorubicin-dexamethasone regimen

Treatment-related mortality (TRM) is not uncommon in patients after the first course of vincristine-doxorubicin-dexamethasone (VAD) chemotherapy,but quite rare after melphalan-prednisolone (MP). This motivated us to compare the rates of TRM after the first course of VAD with those after the first course of MP. We retrospectively assessed survival and TRM in 179 patients treated for multiple myeloma with either MP or VAD. Survival was similar in two groups (P 50.463 in log-rank test). However, TRM was significantly higher inpatients after the first course of VAD (11 in 100 patients, 11.0%) than that after the first course of MP (1 in 79, 1.3%; P 5 0.010). Poor performance status (P 5 0.004) and advanced age (P 5 0.009) before treatment were independent significant factors associated with TRM after the first course of induction therapy. Pyogenic infection was the major cause of TRM after VAD (9 in 11, 81.8%). We concluded that VAD should be cautiously used as induction therapy in multiple myeloma patients, especially in elderly and/or those with poor performance status.

Activations of TRPA1 and P2X receptors are important in ROS-mediated stimulation of capsaicin-sensitive lung vagal afferents by cigarette smoke in rats

Capsaicin-sensitive lung vagal afferents (CSLVAs) are important in detecting pulmonary reactive oxygen species (ROS). We investigated the mechanisms underlying the stimulation of CSLVAs by inhaled cigarette smoke (CS) in 216 anesthetized rats. In spontaneously breathing rats, CS evoked a CSLVA-mediated reflex bradypnea that was prevented by N-acetyl-L-cysteine (NAC; an antioxidant), HC-030031 [a transient receptor potential ankyrin 1 (TRPA1) receptor antagonist], and iso-pyridoxalphosphate-6-azophenyl-2',5'-disulfonate (iso-PPADS; a P2X receptor antagonist). In paralyzed, artificially ventilated rats, CS evoked an increase in CSLVA fiber activity (DeltaFA) that was abolished by NAC and was attenuated by HC-030031, iso-PPADS, indomethacin (Indo; a cyclooxygenase inhibitor), and a combination of apyrase and adenosine deaminase (ADA) (ATP scavengers); the response to CS was reduced to 11.7+/-4.0%, 39.5+/-10.0%, 52.9+/-14.4%, 68.7+/-10.1%, and 47.2+/-12.9% of control, respectively. The suppressive effect on this afferent response was not improved by a combination of HC-030031 and Indo (DeltaFA=39.5+/-10.1% of control) compared with that induced by HC-030031 alone. In contrast, the suppressive effect was enhanced by a combination of HC-030031 and apyrase+ADA (DeltaFA=5.3+/-4.9% of control) or a combination of iso-PPADS and Indo (DeltaFA=23.3+/-7.7% of control) compared with that induced by HC-030031 alone or iso-PPADS alone. This afferent response was not altered by the vehicles for these drugs. These results suggest that activations of TRPA1 receptors by cyclooxygenase metabolites and P2X receptors by ATP are both necessary for the ROS-mediated stimulation of CSLVA fibers by CS in rats.