Changes in PUFA and eicosanoid metabolism during/after apnea diving: a prospective single-center study.

Background: The popularity of apneic diving is continually growing. As apnea diving substantially burdens the cardiovascular system, special focus is warranted. Regarding inflammation processes and associated inflammatory-related diseases (e.g., cardiovascular diseases), eicosanoids play an important role. This study aims to investigate polyunsaturated fatty acids (PUFAs) and eicosanoids in voluntary apnea divers, and so to further improve understanding of pathophysiological processes focusing on proinflammatory effects of temporarily hypercapnic hypoxia.. Methods: The concentration of PUFAs and eicosanoids were investigated in EDTA plasma in apnea divers (n=10) before and immediately after apnea, 0.5 hour and four hours later, applying liquid chromatography-tandem mass spectrometry (LC-MS/MS). Results: Mean age was 41±10 years, and divers performed a mean breath-hold time of 317±111 seconds. PUFAs, eicosanoids and related lipids could be classified in four different kinetical reaction groups following apnea. The first group (e.g., Ω-6 and Ω-3-PUFAs) showed an immediate concentration increase followed by a decrease below baseline four hours after apnea. The second group (e.g., thromboxane B2) showed a slower increase, with its maximum concentration 0.5 hour post-apnea followed by a decrease four hours post-apnea. Group 3 (9- and 13-hydroxyoctadecadienoic acid) is characterized by two concentration increase peaks directly after apnea and four hours afterward compared to baseline. Group 4 (e.g., prostaglandin D2) shows no clear response. Conclusion: Changes in the PUFA metabolism after even a single apnea revealed different kinetics of pro- and anti-inflammatory regulations and changes for oxidative stress levels. Due to the importance of these mediators, apnea diving should be evaluated carefully and be performed only with great caution against the background of cardiovascular diseases and inflammation processes.

Influence of Apnea-induced Hypoxia on Catecholamine Release and Cardiovascular Dynamics.

Prolonged breath-hold causes complex compensatory mechanisms such as increase in blood pressure, redistribution of blood flow, and bradycardia. We tested whether apnea induces an elevation of catecholamine-concentrations in well-trained apneic divers.11 apneic divers performed maximal dry apnea in a horizontal position. Parameters measured during apnea included blood pressure, ECG, and central, in addition to peripheral hemoglobin oxygenation. Peripheral arterial hemoglobin oxygenation was detected by pulse oximetry, whereas peripheral (abdominal) and central (cerebral) tissue oxygenation was measured by Near Infrared Spectroscopy (NIRS). Exhaled O2 and CO2, plasma norepinephrine and epinephrine concentrations were measured before and after apnea.Averaged apnea time was 247±76 s. Systolic blood pressure increased from 135±13 to 185±25 mmHg. End-expiratory CO2 increased from 29±4 mmHg to 49±6 mmHg. Norepinephrine increased from 623±307 to 1 826±984 pg ml-1 and epinephrine from 78±22 to 143±65 pg ml-1 during apnea. Heart rate reduction was inversely correlated with increased norepinephrine (correlation coefficient -0.844, p=0.001). Central (cerebral) O2 desaturation was time-delayed compared to peripheral O2 desaturation as measured by NIRSabdominal and SpO2.Increased norepinephrine caused by apnea may contribute to blood shift from peripheral tissues to the CNS and thus help to preserve cerebral tissue O2 saturation longer than that of peripheral tissue.

Dynamic prediction of the need for renal replacement therapy in intensive care unit patients using a simple and robust model.

We aimed at identifying a model that dynamically predicts future need for renal replacement therapy (RRT) in intensive care unit (ICU) patients and can easily be implemented for online monitoring at the bedside. 7290 interdisciplinary ICU admissions were investigated. Patients with <3 days of stay or RRT in the first 2 days were excluded. 1624 of the remaining 2625 patients had a normal serum creatinine at admission. Every second of these 1624 patients was used for model calibration whereas the other half and, in addition, the 1001 patients with elevated serum creatinine were exclusively used for validation. Discriminant analysis was used to determine and validate a combination of clinical parameters that predicts the need for RRT 72 h ahead. Based on the calibration sample, stepwise discriminant analysis selected the serum values of (1) current urea, (2) current lactate, (3) the ratio of current and admission serum creatinine, and (4) the mean urine output of the previous 24 h. In the validation datasets, the model reached areas under the receiver operating characteristic curve of 0.866 and 0.833 in patients with normal and elevated serum creatinine at admission, respectively. Moreover, the model's predictive value extended to at least 5 days prior to initiation of RRT and exceeded that of the RIFLE classification at all investigated prediction intervals. We identified a robust model that dynamically predicts the future need for RRT successfully. This tool may help improve timing of therapy and prognosis in ICU patients.

Evaluation of near-infrared spectroscopy under apnea-dependent hypoxia in humans.

In this study we investigated the responsiveness of near-infrared spectroscopy (NIRS) recordings measuring regional cerebral tissue oxygenation (rSO2) during hypoxia in apneic divers. The goal was to mimic dynamic hypoxia as present during cardiopulmonary resuscitation, laryngospasm, airway obstruction, or the "cannot ventilate cannot intubate" situation. Ten experienced apneic divers performed maximal breath hold maneuvers under dry conditions. SpO2 was measured by Masimo™ pulse oximetry on the forefinger of the left hand. NIRS was measured by NONIN Medical's EQUANOX™ on the forehead or above the musculus quadriceps femoris. Following apnea median cerebral rSO2 and SpO2 values decreased significantly from 71 to 54 and from 100 to 65%, respectively. As soon as cerebral rSO2 and SpO2 values decreased monotonically the correlation between normalized cerebral rSO2 and SpO2 values was highly significant (Pearson correlation coefficient = 0.893). Prior to correlation analyses, the values were normalized by dividing them by the individual means of stable pre-apneic measurements. Cerebral rSO2 measured re-saturation after termination of apnea significantly earlier (10 s, SD = 3.6 s) compared to SpO2 monitoring (21 s, SD = 4.4 s) [t(9) = 7.703, p < 0.001, r(2) = 0.868]. Our data demonstrate that NIRS monitoring reliably measures dynamic changes in cerebral tissue oxygen saturation, and identifies successful re-saturation faster than SpO2. Measuring cerebral rSO2 may prove beneficial in case of respiratory emergencies and during pulseless situations where SpO2 monitoring is impossible.

Enhancing Data Protection via Auditable Informational Separation of Powers Between Workflow Engine Based Agents: Conceptualization, Implementation, and First Cross-Institutional Experiences.

German best practice standards for secondary use of patient data require pseudonymization and informational separation of powers assuring that identifying data (IDAT), pseudonyms (PSN), and medical data (MDAT) are never simultaneously knowable by any party involved in data provisioning and use. We describe a solution meeting these requirements based on the dynamic interaction of three software agents: the clinical domain agent (CDA), which processes IDAT and MDAT, the trusted third party agent (TTA), which processes IDAT and PSN, and the research domain agent (RDA), which processes PSN and MDAT and delivers pseudonymized datasets. CDA and RDA implement a distributed workflow by employing an off-the-shelf workflow engine. TTA wraps the gPAS framework for pseudonym generation and persistence. All agent interactions are implemented via secured REST-APIs. Rollout to three university hospitals was seamless. The workflow engine allowed meeting various overarching requirements, including auditability of data transfer and pseudonymization, with minimal additional implementation effort. Using a distributed agent architecture based on workflow engine technology thus proved to be an efficient way to meet technical and organizational requirements for provisioning patient data for research purposes in a data protection compliant way.

Monitoring of Cerebral Oxygen Saturation in Interhospital Transport of Patients Receiving Extracorporeal Membrane Oxygenation.

Extracorporeal membrane oxygenation (ECMO) in acute respiratory distress syndrome (ARDS) is used to achieve oxygenation and protect lung ventilation. Near infrared spectroscopy (NIRS) measures cerebral regional tissue oxygenation (rSO 2 ) and may contribute to patient safety during interhospital transport under ECMO support. We evaluated 16 adult ARDS patients undergoing interhospital ECMO transport by measuring cerebral rSO 2 before and after initiation of ECMO support and continuously during transport. To compare peripheral oxygen saturation (SpO 2 ) measurement with rSO 2 , both parameters were analyzed. NIRS monitoring for initiation of ECMO and interhospital transport under ECMO support was feasible, and there was no significant difference in the percentage of achievable valid measurements over time between cerebral rSO 2 (88.4% [95% confidence interval {CI}, 81.3-95.0%]) and standard SpO 2 monitoring 91.7% (95% CI, 86.1-94.2%), p = 0.68. No change in cerebral rSO 2 was observed before 77% (73.5-81%) (median [interquartile range {IQR}]) and after initiation of ECMO support 78% (75-81%), p = 0.2. NIRS for cerebral rSO 2 measurement is feasible during ECMO initiation and interhospital transport. Achievement of valid measurements of cerebral rSO 2 was not superior to SpO 2 . In distinct patients ( e.g. , shock), measurement of cerebral rSO 2 may contribute to improvement of patient safety during interhospital ECMO transport.

Implementation of 2D Barcode Medication Labels and Smart Pumps in Pediatric Acute Care: Lessons Learned.

BACKGROUND: In pediatric intensive care, prescription, administration, and interpretation of drug doses are weight dependent. The use of standardized concentrations simplifies the preparation of drugs and increases safety. For safe administration as well as easy interpretation of intravenous drug dosing regimens with standardized concentrations, the display of weight-related dose rates on the infusion device is of pivotal significance. OBJECTIVES: We report on challenges in the implementation of a new information technology-supported medication workflow. The workflow was introduced on eight beds in the pediatric heart surgery intensive care unit as well as in the pediatric anesthesia at the University of Bonn Medical Center. The proposed workflow utilizes medication labels generated from prescription data from the electronic health record. The generated labels include a two-dimensional barcode to transfer data to the infusion devices. METHODS: Clinical and technical processes were agilely developed. The reliability of the system under real-life conditions was monitored. User satisfaction and potential for improvement were assessed. In addition, a structured survey among the nursing staff was performed. The questionnaire addressed usability as well as the end-users' perception of the effects on patient safety. RESULTS: The workflow has been applied 44,111 times during the pilot phase. A total of 114 known failures in the technical infrastructure were observed. The survey showed good ratings for usability and safety (median "school grade" 2 or B for patient safety, intelligibility, patient identification, and handling). The medical management of the involved acute care facilities rated the process as clearly beneficial regarding patient safety, suggesting a rollout to all pediatric intensive care areas. CONCLUSION: A medical information technology-supported medication workflow can increase user satisfaction and patient safety as perceived by the clinical end-users in pediatric acute care. The successful implementation benefits from an interdisciplinary team, active investigation of possible associated risks, and technical redundancy.

CD44 in hematological neoplasias.

The CD44 protein family spans a large group of transmembrane glycoproteins acquired by alternative splicing and post-translational modifications. The great heterogeneity in molecular structure is reflected in its various important functions: CD44 mediates (1) interaction between cell and extracellular matrix, (2) signal submission, e.g., by acting as co-receptor for membrane-spanning receptor tyrosine kinases or by association with intracellular molecules initiating several signaling pathways, and (3) anchor function connecting to the cytoskeleton via the ezrin-radixin-moesin protein family. The expression pattern of the different CD44 isoforms display strong variations dependent on cell type, state of activation, and differentiation stage. In hematopoietic cells, CD44 mediates interaction of progenitor cells and bone marrow stroma during hematopoiesis, regulates maturation, and activation-induced cell death in T cells, influences neutrophil and macrophage migration as well as cytokine production, and participates in lymphocyte extravasation and migration. CD44 is involved in development and progress of hematological neoplasias by enhancement of apoptotic resistance, invasiveness, as well as regulation of bone marrow homing, and mobilization of leukemia-initiating cells into the peripheral blood. Thereby altered CD44 expression functions as marker for worse prognosis in most hematological malignancies. Additionally, CD44 expression levels can be used to distinguish between different hematological neoplasias and subtypes. Concerning new treatment strategies, CD44 displays promising potential either by direct targeting of CD44 expressed on the malignant cells or reversing an acquired resistance to primary treatment mediated through altered CD44 expression. The former can be achieved by antibody or hyaluronan-based immunotherapy.

Algorithmic surveillance of ICU patients with acute respiratory distress syndrome (ASIC): protocol for a multicentre stepped-wedge cluster randomised quality improvement strategy.

INTRODUCTION: The acute respiratory distress syndrome (ARDS) is a highly relevant entity in critical care with mortality rates of 40%. Despite extensive scientific efforts, outcome-relevant therapeutic measures are still insufficiently practised at the bedside. Thus, there is a clear need to adhere to early diagnosis and sufficient therapy in ARDS, assuring lower mortality and multiple organ failure. METHODS AND ANALYSIS: In this quality improvement strategy (QIS), a decision support system as a mobile application (ASIC app), which uses available clinical real-time data, is implemented to support physicians in timely diagnosis and improvement of adherence to established guidelines in the treatment of ARDS. ASIC is conducted on 31 intensive care units (ICUs) at 8 German university hospitals. It is designed as a multicentre stepped-wedge cluster randomised QIS. ICUs are combined into 12 clusters which are randomised in 12 steps. After preparation (18 months) and a control phase of 8 months for all clusters, the first cluster enters a roll-in phase (3 months) that is followed by the actual QIS phase. The remaining clusters follow in month wise steps. The coprimary key performance indicators (KPIs) consist of the ARDS diagnostic rate and guideline adherence regarding lung-protective ventilation. Secondary KPIs include the prevalence of organ dysfunction within 28 days after diagnosis or ICU discharge, the treatment duration on ICU and the hospital mortality. Furthermore, the user acceptance and usability of new technologies in medicine are examined. To show improvements in healthcare of patients with ARDS, differences in primary and secondary KPIs between control phase and QIS will be tested. ETHICS AND DISSEMINATION: Ethical approval was obtained from the independent Ethics Committee (EC) at the RWTH Aachen Faculty of Medicine (local EC reference number: EK 102/19) and the respective data protection officer in March 2019. The results of the ASIC QIS will be presented at conferences and published in peer-reviewed journals. TRIAL REGISTRATION NUMBER: DRKS00014330.

A Closed-chest Model to Induce Transverse Aortic Constriction in Mice.

Research on cardiac hypertrophy and heart failure is frequently based on pressure overload mouse models induced by TAC. The standard procedure is to perform a partial thoracotomy to visualize the transverse aortic arch. However, the surgical trauma caused by the thoracotomy in open-chest models changes the respiratory physiology as the ribs are dissected and left unattached after chest closure. To prevent this, we established a minimally invasive, closed chest approach via lateral thoracotomy. Herein we approach the aortic arch via the 2nd intercostal space without entering the chest cavities, leaving the mouse with a less traumatic injury to recover from. We perform this operation using standard laboratory settings for open chest TAC procedures with equal survival rates. Apart from maintaining physiological breathing patterns due to the closed chest approach, the mice seem to benefit by showing rapid recovery, as the less invasive technique appears to facilitate a fast healing process and to reduce immune response after trauma.

Prevention and Therapy of Pediatric Emergence Delirium: A National Survey.

INTRODUCTION: Although pediatric emergence delirium (ED) is common, preventive and therapeutic pharmacological treatment is the matter of an international controversial discussion and evidence on different options is partially vague. OBJECTIVE: We therefore examined clinical routine in prevention strategies and postoperative therapy of ED with respect to clinical experience in pediatric anesthesia. METHODS: A web-based survey was developed investigating routine management (prevention and treatment) of ED, facility structure, and patient population. The link was sent to all enlisted members of the German Society of Anesthesiology. RESULTS: We analyzed 1229 questionnaires. Overall, 88% reported ED as a relevant clinical problem; however, only 5% applied assessment scores to define ED. Oral midazolam was reported as standard premedication by 84% of respondents, the second largest group was 'no premedication' (5%). The first choice prevention strategy was to perform total intravenous (propofol) anesthesia (63%). The first choice therapeutic pharmacological treatment depended on clinical experience. Therapeutic propofol was preferentially chosen by more experienced anesthesiologists (5 to >20 patients per week, n = 538), while lesser experienced colleagues (<5 patients per week, n = 676) preferentially applied opioids. Dexmedetomidine (1%) and non-pharmacological (2%) therapy were rarely stated. The highest satisfaction levels for pharmacological therapy of ED were attributed to propofol. CONCLUSIONS: Propofol is the preferred choice for pharmacological prevention and treatment of ED among German anesthesiologists. Further therapy options as well as alternatives to a midazolam-centered premedication procedure are underrepresented.

Sustained apnea induces endothelial activation.

BACKGROUND: Apnea diving has gained worldwide popularity, even though the pathophysiological consequences of this challenging sport on the human body are poorly investigated and understood. This study aims to assess the influence of sustained apnea in healthy volunteers on circulating microparticles (MPs) and microRNAs (miRs), which are established biomarkers reflecting vascular function. HYPOTHESIS: Short intermittent hypoxia due to voluntary breath-holding affects circulating levels of endothelial cell-derived MPs (EMPs) and endothelial cell-derived miRs. METHODS: Under dry laboratory conditions, 10 trained apneic divers performed maximal breath-hold. Venous blood samples were taken, once before and at 4 defined points in time after apnea. Samples were analyzed for circulating EMPs and endothelial miRs. RESULTS: Average apnea time was 329 seconds (±103), and SpO2 at the end of apnea was 79% (±12). Apnea was associated with a time-dependent increase of circulating endothelial cell-derived EMPs and endothelial miRs. Levels of circulating EMPs in the bloodstream reached a peak 4 hours after the apnea period and returned to baseline levels after 24 hours. Circulating miR-126 levels were elevated at all time points after a single voluntary maximal apnea, whereas miR-26 levels were elevated significantly only after 30 minutes and 4 hours. Also miR-21 and miR-92 levels increased, but did not reach the level of significance. CONCLUSIONS: Even a single maximal breath-hold induces acute endothelial activation and should be performed with great caution by subjects with preexisting vascular diseases. Voluntary apnea might be used as a model to simulate changes in endothelial function caused by hypoxia in humans.

Nurse Staffing Calculation in the Emergency Department - Performance-Oriented Calculation Based on the Manchester Triage System at the University Hospital Bonn.

BACKGROUND: To date, there are no valid statistics regarding the number of full time staff necessary for nursing care in emergency departments in Europe. MATERIAL AND METHODS: Staff requirement calculations were performed using state-of-the art procedures which take both fluctuating patient volume and individual staff shortfall rates into consideration. In a longitudinal observational study, the average nursing staff engagement time per patient was assessed for 503 patients. For this purpose, a full-time staffing calculation was estimated based on the five priority levels of the Manchester Triage System (MTS), taking into account specific workload fluctuations (50th-95th percentiles). RESULTS: Patients classified to the MTS category red (n = 35) required the most engagement time with an average of 97.93 min per patient. On weighted average, for orange MTS category patients (n = 118), nursing staff were required for 85.07 min, for patients in the yellow MTS category (n = 181), 40.95 min, while the two MTS categories with the least acute patients, green (n = 129) and blue (n = 40) required 23.18 min and 14.99 min engagement time per patient, respectively. Individual staff shortfall due to sick days and vacation time was 20.87% of the total working hours. When extrapolating this to 21,899 (2010) emergency patients, 67-123 emergency patients (50-95% percentile) per month can be seen by one nurse. The calculated full time staffing requirement depending on the percentiles was 14.8 to 27.1. CONCLUSION: Performance-oriented staff planning offers an objective instrument for calculation of the full-time nursing staff required in emergency departments.

A Model to Simulate Clinically Relevant Hypoxia in Humans.

In case of apnea, arterial partial pressure of oxygen (pO2) decreases, while partial pressure of carbon dioxide (pCO2) increases. To avoid damage to hypoxia sensitive organs such as the brain, compensatory circulatory mechanisms help to maintain an adequate oxygen supply. This is mainly achieved by increased cerebral blood flow. Intermittent hypoxia is a commonly seen phenomenon in patients with obstructive sleep apnea. Acute airway obstruction can also result in hypoxia and hypercapnia. Until now, no adequate model has been established to simulate these dynamics in humans. Previous investigations focusing on human hypoxia used inhaled hypoxic gas mixtures. However, the resulting hypoxia was combined with hyperventilation and is therefore more representative of high altitude environments than of apnea. Furthermore, the transferability of previously performed animal experiments to humans is limited and the pathophysiological background of apnea induced physiological changes is poorly understood. In this study, healthy human apneic divers were utilized to mimic clinically relevant hypoxia and hypercapnia during apnea. Additionally, pulse-oximetry and Near Infrared Spectroscopy (NIRS) were used to evaluate changes in cerebral and peripheral oxygen saturation before, during, and after apnea.

Monitoring of cerebral oxygen saturation during resuscitation in out-of-hospital cardiac arrest: a feasibility study in a physician staffed emergency medical system.

BACKGROUND: Despite recent advances in resuscitation algorithms, neurological injury after cardiac arrest due to cerebral ischemia and reperfusion is one of the reasons for poor neurological outcome. There is currently no adequate means of measuring cerebral perfusion during cardiac arrest. It was the aim of this study to investigate the feasibility of measuring near infrared spectroscopy (NIRS) as a potential surrogate parameter for cerebral perfusion in patients with out-of-hospital resuscitations in a physician-staffed emergency medical service. METHODS: An emergency physician responding to out-of-hospital emergencies was equipped with a NONIN cerebral oximetry device. Cerebral oximetry values (rSO2) were continuously recorded during resuscitation and transport. Feasibility was defined as >80% of total achieved recording time in relation to intended recording time. RESULTS: 10 patients were prospectively enrolled. In 89.8% of total recording time, rSO2 values could be recorded (213 minutes and 20 seconds), thus meeting feasibility criteria. 3 patients experienced return of spontaneous circulation (ROSC). rSO2 during manual cardiopulmonary resuscitation (CPR) was lower in patients who did not experience ROSC compared to the 3 patients with ROSC (31.6%, ± 7.4 versus 37.2% ± 17.0). ROSC was associated with an increase in rSO2. Decrease of rSO2 indicated occurrence of re-arrest in 2 patients. In 2 patients a mechanical chest compression device was used. rSO2 values during mechanical compression were increased by 12.7% and 19.1% compared to manual compression. CONCLUSIONS: NIRS monitoring is feasible during resuscitation of patients with out-of-hospital cardiac arrest and can be a useful tool during resuscitation, leading to an earlier detection of ROSC and re-arrest. Higher initial rSO2 values during CPR seem to be associated with the occurrence of ROSC. The use of mechanical chest compression devices might result in higher rSO2. These findings need to be confirmed by larger studies.

Use of the receptor tyrosine kinase-like orphan receptor 1 (ROR1) as a diagnostic tool in chronic lymphocytic leukemia (CLL).

Flow cytometry is commonly used to establish the diagnosis of chronic lymphocytic leukemia (CLL). A defined combination of antibodies discriminates between normal B cells and CLL cells (coexpression of CD5, CD19, and CD23). The receptor tyrosine-like orphan receptor one (ROR1) is an embryonic glycoprotein involved in several developmental processes. It was shown to be highly and specifically expressed on circulating B lymphoma cells, but not on normal B cells. Here, we examined the potential of ROR1 as a diagnostic marker in initial and follow-up diagnostics of patients with CLL. 105 untreated and 72 treated patients, as well as healthy volunteers were examined using flow cytometry assays. Furthermore, we examined 10 patients with various B cell non-Hodgkin lymphomas (B-NHL). ROR1 was detected using a directly labeled antibody. We detected uniformly high ROR1 expression levels in all CLL samples. In marked contrast, only low or absent ROR1 expression levels were found on B cells from healthy donors. ROR1 expression in CLL patients was not influenced by various treatments. Taken together, ROR1 may be used as a diagnostic marker for CLL. As it is the only antigen which can exclusively be detected on neoplastic B cells it may greatly increase both, specificity as well as sensitivity, in lymphoma diagnostics.

Flow cytometry and polymerase chain reaction-based analyses of minimal residual disease in chronic lymphocytic leukemia.

New therapeutic strategies developed recently for chronic lymphocytic leukemia (CLL) have led to remarkable treatment response rates and complete hematological remissions. This means highly sensitive and specific techniques are increasingly needed to evaluate minimal residual disease (MRD) in CLL patients. Quantitative MRD levels can be used as prognostic markers, where total MRD eradication is associated with prolonged survival. Nowadays, PCR and flow cytometry techniques used to detect MRD in CLL patients can generate reliable and quantitative results with the highest sensitivity. MRD Flow is based on four-color flow cytometry using specific antibody combinations. For allele specific oligonucleotide real-time quantification (ASO RQ) PCR individual primers are designed to detect a specific immunoglobulin heavy chain (IgH) rearrangement in each patient clone. Five comprehensive studies investigated and compared the sensitivity and specificity of both methods. Groups of patients receiving different therapies were analyzed at different time points to generate quantitative MRD levels and MRD kinetics. All studies confirmed that both methods generate equivalent results with regard to sensitivity and MRD quantification, although each method has advantages and disadvantages in the daily routine of a standard hematological laboratory. Here, we review these investigations and compare their results in the light of modern therapies.

High lymphoid enhancer-binding factor-1 expression is associated with disease progression and poor prognosis in chronic lymphocytic leukemia.

We determined lymphoid enhancer-binding factor-1 (LEF1) mRNA expression in 112 chronic lymphocytic leukemia (CLL) samples and assessed correlations with the prognostic markers ZAP70 and CD38, Binet stages, the percentage of lymphocytes in the peripheral blood, and fibromodulin (FMOD) transcripts. The mean LEF1 relative expression ratios (RER) were 53.72 and 37.10 in ZAP70-positive and ZAP70-negative patients, respectively (P=0.004). However, we did not observe a significant difference in LEF1 expression between CD38-positive and CD38-negative patients. Moreover, patients requiring treatment showed a mean LEF1 RER of 85.61 whereas patients in recently diagnosed Binet A stage had a mean of only 22.01 (P<0.001). We also found significant correlations of LEF1 with the percentage of lymphocytes and FMOD expression. Our results suggest that high LEF1 expression is associated with poor prognosis and disease progression. Thus, LEF1 might be involved in the process of disease progression and possibly can serve as a molecular parameter for risk assessment and/or monitoring of CLL.

The vascular endothelial growth factor receptor tyrosine kinase inhibitors vatalanib and pazopanib potently induce apoptosis in chronic lymphocytic leukemia cells in vitro and in vivo.

PURPOSE: There is evidence that vascular endothelial growth factor (VEGF) is a critical microenvironmental factor that exerts angiogenesis-independent effects on the survival of chronic lymphocytic leukemia (CLL) cells. Vatalanib and pazopanib are potent orally available VEGF receptor tyrosine kinase inhibitors. We investigated the efficacy and selectivity of both compounds in CLL cells, simulated potential combination with conventional cytostatics, and tested the effect of both substances on CLL-like tumor xenografts. EXPERIMENTAL DESIGN: Primary CLL and normal peripheral blood cells were tested for viability after incubation with varying concentrations of both inhibitors. Further, phosphorylation status of VEGF receptor on treatment, caspase activation, and poly(ADP-ribose) polymerase cleavage were assessed. Combinations of each inhibitor with fludarabine, vincristine, and doxorubicin were analyzed for possible synergistic effects in vitro. For in vivo testing, mice grafted with the CLL-like cell line JVM-3 were treated orally with each inhibitor. RESULTS: Vatalanib and pazopanib decreased phosphorylation of the VEGF receptor, along with induction of apoptosis in CLL cells in clinically achievable concentrations. Healthy B cells were only mildly affected. Immunoblots showed downregulation of the antiapoptotic proteins XIAP and MCL1, whereas poly(ADP-ribose) polymerase cleavage was increased. Combinations with conventional cytostatic agents resulted in synergistic effects. Treatment of xenografted mice with 100 mg/kg of body weight for 21 days resulted in tumor inhibition rates of 76% (vatalanib) and 77% (pazopanib). In two mice, a total tumor eradication could be observed. No gross systemic toxicity occurred. CONCLUSION: We conclude that VEGF inhibition is a promising new therapeutic approach in CLL. Vatalanib and pazopanib seem to be effective and safe candidates to be further evaluated for this purpose.