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Background: The human phospholipase B-II precursor (HPLBII-P) was originally purified from white blood cells but is also found in other cellular structures, such as kidney glomeruli and tubuli. The objective of this report was to investigate the relationship of HPLBII-P in urine to acute kidney injury in patients with COVID-19. Methods: Urine was collected at admission from 132 patients with COVID-19 admitted to the intensive care units (ICUs) because of respiratory failure. HPLBII-P was measured using a sensitive ELISA. For comparison, human neutrophil lipocalin (HNL) was measured in urine, using the ELISA configured with the monoclonal antibody 763/8F, as a sign of tubular affection in addition to routine biomarkers of kidney disease. Results: Overall, the concentrations of urinary HPLBII-P were almost 3-fold higher in patients with COVID-19 compared to healthy controls (p < 0.0001) and with significantly higher concentrations even in patients with COVID-19 without signs of acute kidney injury (AKI) (p < 0.001). HPLBII-P was further increased in patients with AKI (p < 0.02). HPLBII-P was significantly increased in patients with diabetes mellitus (p = 0.0008) and correlated to plasma glucose (r = 0.29, p = 0.001) and urine albumin concentrations (r = 0.55, p < 0.001). Conclusions: Urine concentrations of HPLBII-P are highly raised in the urine of patients with COVID-19 and relate to AKI and diabetes mellitus. HPLBII-P may reflect glomerular injury and/or increased glomerular cell activity in SARS-CoV-2 infections.

Background: A previous report showed that the urine output of HPLBII-P in patients with diabetes mellitus and SARS-CoV-2 infection was increased as a sign of glomerular dysfunction. The aim of this report was to investigate the relation of the urine output of HPLBII-P to diabetes mellitus in two large community-based elderly populations, i.e., the ULSAM and PIVUS cohorts. Methods: HPLBII-P was measured by an ELISA in the urine of a community-based cohort of 839 men (ULSAM) collected at 77 years of age and in the urine of a community-based cohort of 75-year-old men, n = 387, and women, n = 401 (PIVUS). KIM-1, NGAL, and albumin were measured in urine and cathepsin S and cystatin C in serum. Results: HPLBII-P was significantly raised among males with diabetes in the ULSAM (p < 0.0001) and PIVUS cohorts (p ≤ 0.02), but not in the female cohort of PIVUS. In the female subpopulation of insulin-treated diabetes, HPLBII-P was raised (p = 0.02) as compared to women treated with oral antidiabetics only. In the ULSAM cohort, HPLBII-P was correlated to NGAL, KIM-1, and albumin in urine both in non-DM (all three biomarkers; p < 0.0001) and in DM (NGAL; p = 0.002, KIM-1; p = 0.02 and albumin; p = 0.01). Plasma glucose and HbA1c in blood showed correlations to U-HPLBII-P (r = 0.58, p < 0.001 and r = 0.42, p = 0.004, respectively). U-HPLBII-P and cathepsin S were correlated in the ULSAM group (r = 0.50, p < 0.001). No correlations were observed between U-HPLBII-P and serum creatinine or cystatin C. Conclusions: The urine measurement of HPLBII-P has the potential to become a novel and useful biomarker in the monitoring of glomerular activity in diabetes mellitus.

Recent singing voice synthesis and conversion advancements necessitate robust singing voice deepfake detection (SVDD) models. Current SVDD datasets face challenges due to limited controllability, diversity in deepfake methods, and licensing restrictions. Addressing these gaps, we introduce CtrSVDD, a large-scale, diverse collection of bonafide and deepfake singing vocals. These vocals are synthesized using state-of-the-art methods from publicly accessible singing voice datasets. CtrSVDD includes 47.64 hours of bonafide and 260.34 hours of deepfake singing vocals, spanning 14 deepfake methods and involving 164 singer identities. We also present a baseline system with flexible front-end features, evaluated against a structured train/dev/eval split. The experiments show the importance of feature selection and highlight a need for generalization towards deepfake methods that deviate further from training distribution. The CtrSVDD dataset and baselines are publicly accessible., Comment: Accepted by Interspeech 2024

This paper deals with dynamic quantized consensus of dynamical agents in a general form under packet losses induced by Denial-of-Service (DoS) attacks. The communication channel has limited bandwidth and hence the transmitted signals over the network are subject to quantization. To deal with agent's output, an observer is implemented at each node. The state of the observer is quantized by a finite-level quantizer and then transmitted over the network. To solve the problem of quantizer overflow under malicious packet losses, a zooming-in and out dynamic quantization mechanism is designed. By the new quantized controller proposed in the paper, the zooming-out factor is lower bounded by the spectral radius of the agent's dynamic matrix. A sufficient condition of quantization range is provided under which the finite-level quantizer is free of overflow. A sufficient condition of tolerable DoS attacks for achieving consensus is also provided. At last, we study scalar dynamical agents as a special case and further tighten the zooming-out factor to a value smaller than the agent's dynamic parameter. Under such a zooming-out factor, it is possible to recover the level of tolerable DoS attacks to that of unquantized consensus, and the quantizer is free of overflow.

In this paper, we investigate tracking control of heterogeneous multi-agent systems under Denial-of-Service (DoS) attacks and state quantization. Dynamic quantized mechanisms are designed for inter-follower communication and leader-follower communication. Zooming-in and out factors, and data rates of both mechanisms for preventing quantizer saturation are provided. Our results show that by tuning the inter-follower quantized controller, one cannot improve the resilience beyond a level determined by the data rate of leader-follower quantized communication, i.e., the ceiling effect. Otherwise, overflow of followers' state quantizer can occur. On the other hand, if one selects a "large" data rate for leader-follower quantized communication, then the inter-follower quantized communication determines the resilience, and further increasing the data rate for leader-follower quantized communication cannot improve the resilience, i.e., the bottleneck effect. Simulation examples are provided to justify the results of our paper.

This paper studies distributed Nash equilibrium (NE) seeking under Denial-of-Service (DoS) attacks and quantization. The players can only exchange information with their own direct neighbors. The transmitted information is subject to quantization and packet losses induced by malicious DoS attacks. We propose a quantized distributed NE seeking strategy based on the approach of dynamic quantized consensus. To solve the quantizer saturation problem caused by DoS attacks, the quantization mechanism is equipped to have zooming-in and holding capabilities, in which the holding capability is consistent with the results in quantized consensus under DoS. A sufficient condition on the number of quantizer levels is provided, under which the quantizers are free from saturation under DoS attacks. The proposed distributed quantized NE seeking strategy is shown to have the so-called maximum resilience to DoS attacks. Namely, if the bound characterizing the maximum resilience is violated, an attacker can deny all the transmissions and hence distributed NE seeking is impossible.

The mean exit time escaping basin of attraction in the presence of white noise is of practical importance in various scientific fields. In this work, we propose a strategy to control mean exit time of general stochastic dynamical systems to achieve a desired value based on the quasipotential concept and machine learning. Specifically, we develop a neural network architecture to compute the global quasipotential function. Then we design a systematic iterated numerical algorithm to calculate the controller for a given mean exit time. Moreover, we identify the most probable path between metastable attractors with help of the effective Hamilton-Jacobi scheme and the trained neural network. Numerical experiments demonstrate that our control strategy is effective and sufficiently accurate.

The large adoption of EVs brings practical interest to the operation optimization of the charging station. The joint scheduling of pricing and charging control will achieve a win-win situation both for the charging station and EV drivers, thus enhancing the operational capability of the station. We consider this important problem in this paper and make the following contributions. First, a joint scheduling model of pricing and charging control is developed to maximize the expected social welfare of the charging station considering the Quality of Service and the price fluctuation sensitivity of EV drivers. It is formulated as a Markov decision process with variance criterion to capture uncertainties during operation. Second, a two-phase on-line policy learning algorithm is proposed to solve this joint scheduling problem. In the first phase, it implements event-based policy iteration to find the optimal pricing scheme, while in the second phase, it implements scenario-based model predictive control for smart charging under the updated pricing scheme. Third, by leveraging the performance difference theory, the optimality of the proposed algorithm is theoretically analyzed. Numerical experiments for a charging station with distributed generation and energy storage demonstrate the effectiveness of the proposed method and the improved social welfare of the charging station.

Modeling human mobility helps to understand how people are accessing resources and physically contacting with each other in cities, and thus contributes to various applications such as urban planning, epidemic control, and location-based advertisement. Next location prediction is one decisive task in individual human mobility modeling and is usually viewed as sequence modeling, solved with Markov or RNN-based methods. However, the existing models paid little attention to the logic of individual travel decisions and the reproducibility of the collective behavior of population. To this end, we propose a Causal and Spatial-constrained Long and Short-term Learner (CSLSL) for next location prediction. CSLSL utilizes a causal structure based on multi-task learning to explicitly model the "\textit{when$\rightarrow$what$\rightarrow$where}", a.k.a. "\textit{time$\rightarrow$activity$\rightarrow$location}" decision logic. We next propose a spatial-constrained loss function as an auxiliary task, to ensure the consistency between the predicted and actual spatial distribution of travelers' destinations. Moreover, CSLSL adopts modules named Long and Short-term Capturer (LSC) to learn the transition regularities across different time spans. Extensive experiments on three real-world datasets show promising performance improvements of CSLSL over baselines and confirm the effectiveness of introducing the causality and consistency constraints. The implementation is available at https://github.com/urbanmobility/CSLSL., Comment: Updated version (We have corrected the title error in the previous version.)

Counting numbers of blood neutrophils is one of the most common laboratory tests in modern clinical medicine. In this report, we have tested the idea that immunoassay of major constituents of mature neutrophils might serve as proxy of cell counting and allow the development of rapid and simple point-of-care tests. The procedure may also allow for the estimate of the state of maturity of the circulating blood cells. Immunoassays for myeloperoxidase (MPO) and lactoferrin (LF) were used to measure the respective protein in whole blood extracts of 275 unselected hospitalized patient and in 51 healthy controls and leukemia patients of which eight were followed before, during and after remission treatment. MPO was correlated to neutrophil counts in the unselected hospitalized population (r = 0.95, p <.0001). Huge variations were seen in whole blood extracts of patients with AML with very high MPO/LF ratios in half of the AML patients and in all three patients with APL. In extracts from patients with ALL no difference was found in the ratio as compared to healthy persons. The monitoring of AML patients during remission treatment showed intriguing patterns one of which suggested the possibility to monitor the myelopoietic activity in the bone marrow during the recovery phase. We show a novel and easy technology to count mature neutrophils in blood and also to monitor myeloid cell maturity in the blood as well as myelopoietic activity in the bone marrow. The technology lends itself to the development of a rapid and simple point-of-care test.

Counting numbers of blood neutrophils is one of the most common laboratory tests in modern clinical medicine. In this report, we have tested the idea that immunoassay of major constituents of mature neutrophils might serve as proxy of cell counting and allow the development of rapid and simple point-of-care tests. The procedure may also allow for the estimate of the state of maturity of the circulating blood cells. Immunoassays for myeloperoxidase (MPO) and lactoferrin (LF) were used to measure the respective protein in whole blood extracts of 275 unselected hospitalized patient and in 51 healthy controls and leukemia patients of which eight were followed before, during and after remission treatment. MPO was correlated to neutrophil counts in the unselected hospitalized population (r = 0.95, p <.0001). Huge variations were seen in whole blood extracts of patients with AML with very high MPO/LF ratios in half of the AML patients and in all three patients with APL. In extracts from patients with ALL no difference was found in the ratio as compared to healthy persons. The monitoring of AML patients during remission treatment showed intriguing patterns one of which suggested the possibility to monitor the myelopoietic activity in the bone marrow during the recovery phase. We show a novel and easy technology to count mature neutrophils in blood and also to monitor myeloid cell maturity in the blood as well as myelopoietic activity in the bone marrow. The technology lends itself to the development of a rapid and simple point-of-care test.

Counting numbers of blood neutrophils is one of the most common laboratory tests in modern clinical medicine. In this report, we have tested the idea that immunoassay of major constituents of mature neutrophils might serve as proxy of cell counting and allow the development of rapid and simple point-of-care tests. The procedure may also allow for the estimate of the state of maturity of the circulating blood cells. Immunoassays for myeloperoxidase (MPO) and lactoferrin (LF) were used to measure the respective protein in whole blood extracts of 275 unselected hospitalized patient and in 51 healthy controls and leukemia patients of which eight were followed before, during and after remission treatment. MPO was correlated to neutrophil counts in the unselected hospitalized population (r = 0.95, p <.0001). Huge variations were seen in whole blood extracts of patients with AML with very high MPO/LF ratios in half of the AML patients and in all three patients with APL. In extracts from patients with ALL no difference was found in the ratio as compared to healthy persons. The monitoring of AML patients during remission treatment showed intriguing patterns one of which suggested the possibility to monitor the myelopoietic activity in the bone marrow during the recovery phase. We show a novel and easy technology to count mature neutrophils in blood and also to monitor myeloid cell maturity in the blood as well as myelopoietic activity in the bone marrow. The technology lends itself to the development of a rapid and simple point-of-care test.

Counting numbers of blood neutrophils is one of the most common laboratory tests in modern clinical medicine. In this report, we have tested the idea that immunoassay of major constituents of mature neutrophils might serve as proxy of cell counting and allow the development of rapid and simple point-of-care tests. The procedure may also allow for the estimate of the state of maturity of the circulating blood cells. Immunoassays for myeloperoxidase (MPO) and lactoferrin (LF) were used to measure the respective protein in whole blood extracts of 275 unselected hospitalized patient and in 51 healthy controls and leukemia patients of which eight were followed before, during and after remission treatment. MPO was correlated to neutrophil counts in the unselected hospitalized population (r = 0.95, p <.0001). Huge variations were seen in whole blood extracts of patients with AML with very high MPO/LF ratios in half of the AML patients and in all three patients with APL. In extracts from patients with ALL no difference was found in the ratio as compared to healthy persons. The monitoring of AML patients during remission treatment showed intriguing patterns one of which suggested the possibility to monitor the myelopoietic activity in the bone marrow during the recovery phase. We show a novel and easy technology to count mature neutrophils in blood and also to monitor myeloid cell maturity in the blood as well as myelopoietic activity in the bone marrow. The technology lends itself to the development of a rapid and simple point-of-care test.

The distributed convex optimization problem over the multi-agent system is considered in this paper, and it is assumed that each agent possesses its own cost function and communicates with its neighbours over a sequence of time-varying directed graphs. However, due to some reasons there exist communication delays while agents receive information from other agents, and we are going to seek the optimal value of the sum of agents' loss functions in this case. We desire to handle this problem with the push-sum distributed dual averaging (PS-DDA) algorithm. It is proved that this algorithm converges and the error decays at a rate $\mathcal{O}\left(T^{-0.5}\right)$ with proper step size, where $T$ is iteration span. The main result presented in this paper also illustrates the convergence of the proposed algorithm is related to the maximum value of the communication delay on one edge. We finally apply the theoretical results to numerical simulations to show the PS-DDA algorithm's performance.

Most GAN(Generative Adversarial Network)-based approaches towards high-fidelity waveform generation heavily rely on discriminators to improve their performance. However, GAN methods introduce much uncertainty into the generation process and often result in mismatches of pitch and intensity, which is fatal when it comes to sensitive use cases such as singing voice synthesis(SVS). To address this problem, we propose RefineGAN, a high-fidelity neural vocoder focused on the robustness, pitch and intensity accuracy, and high-speed full-band audio generation. We applyed a pitch-guided refine architecture with a multi-scale spectrogram-based loss function to help stabilize the training process and maintain the robustness of the neural vocoder while using the GAN-based training method. Audio generated using this method shows a better performance in subjective tests when compared with the ground-truth audio. This result shows that the fidelity is even improved during the waveform reconstruction by eliminating defects produced by recording procedures. Moreover, it shows that models trained on a specified type of data can perform on totally unseen language and unseen speaker identically well. Generated sample pairs are provided onhttps://timedomain-tech.github.io/refinegan/., Comment: Submitted to INTERSPEECH2022

With the rapid increase of valuable observational, experimental and simulated data for complex systems, much efforts have been devoted to identifying governing laws underlying the evolution of these systems. Despite the wide applications of non-Gaussian fluctuations in numerous physical phenomena, the data-driven approaches to extract stochastic dynamical systems with (non-Gaussian) L\'evy noise are relatively few so far. In this work, we propose a data-driven method to extract stochastic dynamical systems with $\alpha$-stable L\'evy noise from short burst data based on the properties of $\alpha$-stable distributions. More specifically, we first estimate the L\'evy jump measure and noise intensity via computing mean and variance of the amplitude of the increment of the sample paths. Then we approximate the drift coefficient by combining nonlocal Kramers-Moyal formulas with normalizing flows. Numerical experiments on one- and two-dimensional prototypical examples illustrate the accuracy and effectiveness of our method. This approach will become an effective scientific tool in discovering stochastic governing laws of complex phenomena and understanding dynamical behaviors under non-Gaussian fluctuations., Comment: arXiv admin note: text overlap with arXiv:2108.12570

Counting numbers of blood neutrophils is one of the most common laboratory tests in modern clinical medicine. In this report, we have tested the idea that immunoassay of major constituents of mature neutrophils might serve as proxy of cell counting and allow the development of rapid and simple point-of-care tests. The procedure may also allow for the estimate of the state of maturity of the circulating blood cells. Immunoassays for myeloperoxidase (MPO) and lactoferrin (LF) were used to measure the respective protein in whole blood extracts of 275 unselected hospitalized patient and in 51 healthy controls and leukemia patients of which eight were followed before, during and after remission treatment. MPO was correlated to neutrophil counts in the unselected hospitalized population (r = 0.95, p <.0001). Huge variations were seen in whole blood extracts of patients with AML with very high MPO/LF ratios in half of the AML patients and in all three patients with APL. In extracts from patients with ALL no difference was found in the ratio as compared to healthy persons. The monitoring of AML patients during remission treatment showed intriguing patterns one of which suggested the possibility to monitor the myelopoietic activity in the bone marrow during the recovery phase. We show a novel and easy technology to count mature neutrophils in blood and also to monitor myeloid cell maturity in the blood as well as myelopoietic activity in the bone marrow. The technology lends itself to the development of a rapid and simple point-of-care test.

Background: Acute infections affect all of us at least once or twice a year. Sometimes the infection prompts a visit to our doctor, and the question asked by the patient and the doctor is whether the infection should be treated with antibiotics or not. This is an important question because unnecessary prescription of antibiotics adds to the increasing problem of antibiotics resistance. Objective means to determine whether the infection is caused by bacteria or virus, therefore, are necessary tools for the doctor. Content: White blood cell counts, C-reactive protein, and other acute-phase reactants in blood are important tools and are commonly used, but unfortunately lack in sensitivity and specificity. In this review we describe some novel biomarkers with increased clinical performance in this regard. The superior biomarker is human neutrophil lipocalin (HNL), a protein released from activated blood neutrophils. HNL may be measured in serum, plasma, or in whole blood after activation with a neutrophil activator. The diagnostic accuracy in the distinction between bacterial and viral acute infections was shown to be in the range of 90%-95% when measured in serum or activated whole blood. Summary: A point-of-care assay for the measurement of HNL in whole blood is currently being developed, which will allow the diagnosis of acute infections within 5-10 min. For certain indications, HNL measurement may be complemented by 1 or 2 other biomarkers, which may increase the diagnostic discrimination between bacterial and viral infections even further.

OBJECTIVES: The distinction between bacterial and viral causes of acute infections is a major clinical challenge. In this report we investigate the diagnostic performance in this regard of nine candidate biomarkers together with HNL (Human Neutrophil Lipocalin). METHODS: Blood was obtained from patients with symptoms of infectious (n = 581). HNL was measured in whole blood (B-HNL) after pre-activation with the neutrophil activator fMLP or in plasma (P-HNL). Azurocidin also known as heparin-binding protein (HBP), Calprotectin, PMN-CD64, CRP (C-reactive protein), IP-10 (Interferon γ-induced Protein 10 kDa), PCT (Procalcitonin), TK1 (Thymidine kinase 1), TRAIL (TNF-related apoptosis-inducing ligand) were measured in plasma/serum. Area under the ROC (receiver operating characteristics) curve (AuROC) was used for the evaluation of the clinical performance of the biomarkers. RESULTS: Side-by-side comparisons of the ten biomarkers showed large difference in the AuROC with B-HNL being the superior biomarker (0.91, 95% CI 0.86-0.95) and with the other nine biomarkers varying from AuROC of 0.63-0.79. The combination of B-HNL with IP-10 and/or TRAIL increased the diagnostic performance further to AuROCs of 0.94-0.97. The AuROCs of the combination of CRP with IP-10 and/or TRAIL were significantly lower than combinations with B-HNL 0.87 (95% CI 0.83-0.91). CONCLUSION: The diagnostic performance of whole blood activated HNL was superior in the distinction between bacterial or viral infections. The addition of IP-10 and/or TRAIL to the diagnostic algorithm increased the performance of B-HNL further. The rapid analysis of HNL, reflecting bacterial infections, together with biomarkers reflecting viral infections may be the ideal combination of diagnostic biomarkers of acute infections.

Purpose: To assess the value of dimeric neutrophil-gelatinase associated lipocalin (NGAL) as an early marker of bacterial infection and its response to antibiotic therapy in intensive care unit (ICU) patients. Materials & methods: We measured daily plasma dNGAL in 198 patients admitted to a mixed ICU. Likelihood of infection was determined with International Sepsis Forum criteria. Wemeasured dNGAL in 145 healthy controls to establish normal values. Results: ICU patients had higher dNGAL than healthy controls. A suspected or confirmed infection was independently associated with 90% (95% CI 15-215%) higher dNGAL than absence of infection. We observed no association between acute kidney injury and dNGAL. Diagnostic accuracy at antibiotic treatment initiation, assessed with area under the receiver-operating characteristics curve (AUC-ROC), for dNGAL was 0.70 (95% CI 0.60-0.79). AUC-ROC for dNGAL 24 h before antibiotic treatment initiation was 0.54 (95% CI 0.41-0.66). The mean (95% CI) change of dNGAL in the first 2 days after appropriate antibiotic therapy initiation was -31 (-49,-13)%. Conclusions: In our cohort of ICU patients, plasma dNGAL was associated with presence of bacterial infections independent of AKI but it performed poor as a predictor of infections. Following antibiotic therapy, dNGAL markedly decreased-supporting further exploration of dNGAL-guided antibiotic de-escalation.

This paper studies coordinated control of multiple Lagrangian systems with parametric uncertainties subject to external disturbances by proposing a fully distributed continuous control law based on the improved self-tuning adaptive observer inspired by non-identifier-based high-gain adaptive control technique. Under this distributed continuous control law, a group of Lagrangian systems are driven to the convex hull spanned by multiple heterogenous dynamic leaders, which can be any combination of step signals of arbitrary unknown magnitudes, ramp signals of arbitrary unknown slopes, and sinusoidal signals of arbitrary unknown amplitudes, initial phases, and any unknown frequencies. It is also worth to mention that this control law we propose, depending neither on any information of leader systems for uninformed followers, nor on external disturbances, even independent of neighbors' velocity, can achieve asymptotic tracking of multiple leaders without any additional condition instead of ensuring the ultimate boundedness of the containment error as in the literature., QC 20171107

The distinction between acute infections of bacterial or viral causes is clinically important, but often very difficult even for experienced doctors. Previous studies indicated that serum measurements of HNL (Human Neutrophil Lipocalin) might be a superior diagnostic means in this regard, but also indicated that the antibody conformation of the HNL assay might have an impact on the diagnostic performance. The aim of the present report was to examine this further. Methods: Several different (n = 24) HNL ELISA assays were developed using different combinations of monoclonal and polyclonal HNL antibodies. Sera were collected from healthy persons (n = 188) and from 155 patients with acute infections.before any antibiotics treatment. The patients were diagnosed as having bacterial (n = 69) or viral causes (n = 86) of their infections. Plasma and serum were also examined by Western blotting using HNL-specific polyclonal antibodies. Results: The optimal assay format for the distinction between bacterial and viral infection resulted in an area under the receiver operating characteristics curve (AuROC) for S-HNL of 0.98. (95% CI 0.94-1.00) as compared to 0.83 (0.76-0.88) for blood neutrophil counts and 0.69 (0.61-0.76) for S-CRP. Results also showed that different assay formats of HNL identified monomeric and dimeric HNL differently, the monomeric HNL being elevated in viral infections and the dimeric HNL being elevated in bacterial infections. Conclusion: We conclude that serum theasurement of HNL is a superior diagnostic means to distinguish between acute infections caused by bacteria or virus. For optimal clinical performance the immunoassay should address conformational epitopes in the dimeric HNL.

The distinction between causes of acute infections is a major clinical challenge. Current biomarkers, however, are not sufficiently accurate. Human neutrophil lipocalin (HNL) concentrations in serum or whole blood activated by formyl-methionine-leucine-phenylalanine (fMLP) were shown to distinguish acute infections of bacterial or viral cause with high accuracy. The aim was therefore to compare the clinical performance of HNL with currently used biomarkers. Seven hundred twenty-five subjects (144 healthy controls and 581 patients with signs and symptoms of acute infections) were included in the study. C-reactive protein (CRP), the expression of CD64 on neutrophils, procalcitonin (PCT), and blood neutrophil counts were measured by established techniques, and HNL concentrations were measured in whole-blood samples after activation with fMLP. All tested biomarkers were elevated in bacterial as opposed to viral infections (P<0.001). CRP, PCT, and CD64 expression in neutrophils was elevated in viral infections compared to healthy controls (P<0.001). In the distinction between healthy controls and patients with bacterial infections, the areas under the receiver operating characteristic (ROC) curves were >0.85 for all biomarkers, whereas for the distinction between bacterial and viral infections, only HNL concentration in fMLP-activated whole blood showed an area under the ROC curve (AUROC) of >0.90 and superior clinical performance. The clinical performance of HNL in fMLP-activated whole blood was superior to current biomarkers and similar to previous results of HNL in serum. The procedure can be adopted for point-of-care testing with response times of <15 min.

The distinction between causes of acute infections is a major clinical challenge. Current biomarkers, however, are not sufficiently accurate. Human neutrophil lipocalin (HNL) in serum distinguishes acute infections with high accuracy, but in the emergency setting the assay time should be <15-20 min, which excludes the use of serum samples. The aim was therefore to develop a novel rapid assay principle and test its clinical performance. Methods: Serum and neutrophils obtained from 84 infected and 20 healthy subjects were used in the experimental study. 725 subjects (144 healthy controls and 581 patients with signs and symptoms of acute infections) were included in the clinical study. HNL was measured in EDTA-plasma by ELISA or in heparinized whole blood after fMLP activation by a prototype point-of-care assay. Results: Increased release of HNL from neutrophils after activation with fMLP was seen already after 5 min incubation. The release of HNL from purified neutrophils after 15 min incubation with fMLP was significantly correlated to the HNL concentrations in serum obtained from the same patient (r = 0.74, p < 0.001). In the distinction between healthy controls and patients with bacterial infections, the areas under the ROC-curves were 0.95 (95% CI 0.91-0.97) and 0.88 (95% CI 0.84-0.91) for HNL in fMLP-activated whole blood and EDTA-plasma, respectively, (p <0.001) and in the distinction between bacterial and viral infections 0.91 (95% CI 0.86-0.95) and 0.76 (95% CI 0.70-0.81), respectively (p <0.001). Conclusion: The clinical performance of HNL in fMLP-activated whole blood was superior to HNL in EDTA-plasma and similar to HNL in serum. The procedure can be adopted for point-of-care testing with response times of <15 min.

The distinction between causes of acute infections is a major clinical challenge. Current biomarkers, however, are not sufficiently accurate. Human neutrophil lipocalin (HNL) concentrations in serum or whole blood activated by formyl-methionine-leucine-phenylalanine (fMLP) were shown to distinguish acute infections of bacterial or viral cause with high accuracy. The aim was therefore to compare the clinical performance of HNL with currently used biomarkers. Seven hundred twenty-five subjects (144 healthy controls and 581 patients with signs and symptoms of acute infections) were included in the study. C-reactive protein (CRP), the expression of CD64 on neutrophils, procalcitonin (PCT), and blood neutrophil counts were measured by established techniques, and HNL concentrations were measured in whole-blood samples after activation with fMLP. All tested biomarkers were elevated in bacterial as opposed to viral infections (P<0.001). CRP, PCT, and CD64 expression in neutrophils was elevated in viral infections compared to healthy controls (P<0.001). In the distinction between healthy controls and patients with bacterial infections, the areas under the receiver operating characteristic (ROC) curves were >0.85 for all biomarkers, whereas for the distinction between bacterial and viral infections, only HNL concentration in fMLP-activated whole blood showed an area under the ROC curve (AUROC) of >0.90 and superior clinical performance. The clinical performance of HNL in fMLP-activated whole blood was superior to current biomarkers and similar to previous results of HNL in serum. The procedure can be adopted for point-of-care testing with response times of <15 min.

The distinction between causes of acute infections is a major clinical challenge. Current biomarkers, however, are not sufficiently accurate. Human neutrophil lipocalin (HNL) concentrations in serum or whole blood activated by formyl-methionine-leucine-phenylalanine (fMLP) were shown to distinguish acute infections of bacterial or viral cause with high accuracy. The aim was therefore to compare the clinical performance of HNL with currently used biomarkers. Seven hundred twenty-five subjects (144 healthy controls and 581 patients with signs and symptoms of acute infections) were included in the study. C-reactive protein (CRP), the expression of CD64 on neutrophils, procalcitonin (PCT), and blood neutrophil counts were measured by established techniques, and HNL concentrations were measured in whole-blood samples after activation with fMLP. All tested biomarkers were elevated in bacterial as opposed to viral infections (P<0.001). CRP, PCT, and CD64 expression in neutrophils was elevated in viral infections compared to healthy controls (P<0.001). In the distinction between healthy controls and patients with bacterial infections, the areas under the receiver operating characteristic (ROC) curves were >0.85 for all biomarkers, whereas for the distinction between bacterial and viral infections, only HNL concentration in fMLP-activated whole blood showed an area under the ROC curve (AUROC) of >0.90 and superior clinical performance. The clinical performance of HNL in fMLP-activated whole blood was superior to current biomarkers and similar to previous results of HNL in serum. The procedure can be adopted for point-of-care testing with response times of <15 min.

The distinction between causes of acute infections is a major clinical challenge. Current biomarkers, however, are not sufficiently accurate. Human neutrophil lipocalin (HNL) concentrations in serum or whole blood activated by formyl-methionine-leucine-phenylalanine (fMLP) were shown to distinguish acute infections of bacterial or viral cause with high accuracy. The aim was therefore to compare the clinical performance of HNL with currently used biomarkers. Seven hundred twenty-five subjects (144 healthy controls and 581 patients with signs and symptoms of acute infections) were included in the study. C-reactive protein (CRP), the expression of CD64 on neutrophils, procalcitonin (PCT), and blood neutrophil counts were measured by established techniques, and HNL concentrations were measured in whole-blood samples after activation with fMLP. All tested biomarkers were elevated in bacterial as opposed to viral infections (P<0.001). CRP, PCT, and CD64 expression in neutrophils was elevated in viral infections compared to healthy controls (P<0.001). In the distinction between healthy controls and patients with bacterial infections, the areas under the receiver operating characteristic (ROC) curves were >0.85 for all biomarkers, whereas for the distinction between bacterial and viral infections, only HNL concentration in fMLP-activated whole blood showed an area under the ROC curve (AUROC) of >0.90 and superior clinical performance. The clinical performance of HNL in fMLP-activated whole blood was superior to current biomarkers and similar to previous results of HNL in serum. The procedure can be adopted for point-of-care testing with response times of <15 min.

The distinction between causes of acute infections is a major clinical challenge. Current biomarkers, however, are not sufficiently accurate. Human neutrophil lipocalin (HNL) concentrations in serum or whole blood activated by formyl-methionine-leucine-phenylalanine (fMLP) were shown to distinguish acute infections of bacterial or viral cause with high accuracy. The aim was therefore to compare the clinical performance of HNL with currently used biomarkers. Seven hundred twenty-five subjects (144 healthy controls and 581 patients with signs and symptoms of acute infections) were included in the study. C-reactive protein (CRP), the expression of CD64 on neutrophils, procalcitonin (PCT), and blood neutrophil counts were measured by established techniques, and HNL concentrations were measured in whole-blood samples after activation with fMLP. All tested biomarkers were elevated in bacterial as opposed to viral infections (P<0.001). CRP, PCT, and CD64 expression in neutrophils was elevated in viral infections compared to healthy controls (P<0.001). In the distinction between healthy controls and patients with bacterial infections, the areas under the receiver operating characteristic (ROC) curves were >0.85 for all biomarkers, whereas for the distinction between bacterial and viral infections, only HNL concentration in fMLP-activated whole blood showed an area under the ROC curve (AUROC) of >0.90 and superior clinical performance. The clinical performance of HNL in fMLP-activated whole blood was superior to current biomarkers and similar to previous results of HNL in serum. The procedure can be adopted for point-of-care testing with response times of <15 min.

Objective: Neutrophil gelatinase-associated lipocalin (NGAL) is secreted by injured kidney cells as well as by activated neutrophils in response to bacterial infections. We assessed the influence of acute renal dysfunction on the association between plasma NGAL and sepsis. Methods: NGAL was measured daily in 138 critically ill patients. Simultaneous recordings of sepsis status and fluctuations in renal function were made. Results: Elevated NGAL was associated with sepsis independent of level of acute renal dysfunction. A cut-off value of 98 ng/mL distinguished sepsis from systemic inflammation with high sensitivity (0.77) and specificity (0.79). Conclusions: Plasma NGAL can help clinicians to identify bacterial infections in critically ill patients.

Different molecular forms of urinary neutrophil gelatinase-associated lipocalin (NGAL) have recently been discovered. We aimed to explore the nature, source and discriminatory value of urinary NGAL in intensive care unit (ICU) patients. We simultaneously measured plasma NGAL (pNGAL), urinary NGAL (uNGAL), and estimated monomeric and homodimeric uNGAL contribution using Western blotting-validated enzyme-linked immunosorbent assays [uNGAL(E1) and uNGAL(E2)] and their calculated ratio in 102 patients with the systemic inflammatory response syndrome and oliguria, and/or a creatinine rise of > 25 mu mol/L. Bland-Altman analysis demonstrated that, despite correlating well (r = 0.988), uNGAL and uNGAL(E1) were clinically distinct, lacking both accuracy and precision (bias: 266.23; 95 % CI 82.03-450.44 ng/mg creatinine; limits of agreement: -1,573.86 to 2,106.32 ng/mg creatinine). At best, urinary forms of NGAL are fair (area under the receiver operating characteristic [AUROC] a parts per thousand currency sign0.799) predictors of renal or patient outcome; most perform significantly worse. The 44 patients with a primarily monomeric source of uNGAL had higher pNGAL (118.5 ng/ml vs. 72.5 ng/ml; p < 0.001), remaining significant following Bonferroni correction. uNGAL is not a useful predictor of outcome in this ICU population. uNGAL patterns may predict distinct clinical phenotypes. The nature and source of uNGAL are complex and challenge the utility of NGAL as a uniform biomarker.

BACKGROUND: Prolylcarboxypeptidase (PRCP) (angiotensinase C) has 3 major targets, angiotensin II, prekallikrein, and alpha-melanocyte stimulating hormone(1-13). The truncation of the latter leads to loss in appetite regulation and obesity in experimental animals. The objectives of this study were to purify PRCP from a native source, establish a sensitive immunoassay for PRCP, and relate plasma PRCP concentrations to signs and symptoms of obesity, diabetes mellitus, and cardiovascular dysfunction. METHODS: Purification of PRCP from human neutrophils and establishment of a sensitive ELISA was carried out with the use of samples from study participants. Three cohorts were studied: healthy individuals (n = 40); a chest pain cohort (Fast Assessment of Thoracic Pain by Neural Networks) (n = 165); and a community-based cohort [Prospective Investigation of the Vasculature in Uppsala Seniors (PIVUS)] (n = 1004). RESULTS: PRCP was purified to homogeneity. Mean (SD) plasma concentrations in healthy individuals were 12.9 (3.2), mu g/L and were increased in patients with chest pain and in patients with obesity and/or diabetes mellitus (P < 0.0001). In the PIVUS cohort the concentrations were related to several measures of arterial plaque formation, thickness of arterial intima media and posterior wall of the heart (P = 0.04-0.000005); the Framingham score (r = 0.14, P < 0.0001); and concentrations of C-reactive protein (r = 0.16, P < 0.0001) and N-terminal pro B-type natriuretic peptide (r = -0.13, P < 0.0001). CONCLUSIONS: Plasma concentrations of PRCP may be used to reflect metabolic conditions in individuals with obesity and diabetes mellitus. The associations of PRCP concentrations with signs of cardiovascular dysfunction and cardiovascular abnormalities suggest a pivotal role of the enzyme in disease. (c) 2012 American Association for Clinical Chemistry

Background: The distinction between monomeric human neutrophil lipocalin/neutrophil gelatinase-associated lipocalin (HNL/NGAL), secreted by injured kidney tubular cells, and dimeric HNL/NGAL, released by activated neutrophils, is important to accurately diagnose acute kidney injury (AKI). Methods: 132 urine samples from 44 intensive care unit (ICU) patients and five urine samples from non-ICU patients with urinary tract infections (UTIs) were analyzed by two monoclonal enzyme-linked immunosorbent assays (ELISA-1 and ELISA-2). The presence of monomeric and/or dimeric HNL/NGAL in each sample was visualized by Western blotting. Results: The ELISA-1 detected both monomeric and dimeric HNL/NGAL whereas the ELISA-2 almost exclusively detected dimeric HNL/NGAL with an area under the receiver-operating characteristics curve (AuROC) of 0.90. The ELISA-1/ELISA-2 ratio detected the monomeric form with an AuROC of 0.92. In 32 AKI patients, dimer-specific EUSA-2 levels decreased pre-AKI whereas the monomer-specific ELISA-1/ELISA-2 ratio gradually increased beyond AKI diagnosis. High EUSA-2 levels and/or low ELISA-1/ELISA-2 ratios detected a predominance of dimeric HNL/NGAL in urine from the patients with tills. Conclusions: In combination, our two ELISAs distinguish monomeric HNL/NGAL, produced by the kidney epithelium, from dimeric HNL/NGAL, released by neutrophils during AKI development, as well as reduce the confounding effect of neutrophil involvement when bacteriuria is present.

To study the impact of inflammation/sepsis on the concentrations of neutrophil gelatinase-associated lipocalin (NGAL) in plasma and urine in adult intensive care unit (ICU) patients and to estimate the predictive properties of NGAL in plasma and urine for early detection of acute kidney injury (AKI) in patients with septic shock. Sixty-five patients admitted to the general ICU at the Karolinska University Hospital Solna, Sweden, with normal plasma creatinine were assessed for eligibility. Twenty-seven patients with systemic inflammatory response syndrome (SIRS), severe sepsis, or septic shock without AKI and 18 patients with septic shock and concomitant AKI were included in the final analysis. Plasma and urine were analyzed twice daily for plasma NGAL (pNGAL), C-reactive protein (CRP), procalcitonin, myeloperoxidase, plasma cystatin C, plasma creatinine, urine NGAL (uNGAL), urine cystatin C, and urine alpha 1-microglobulin. Of the 45 patients, 40 had elevated peak levels of pNGAL. Peak levels of pNGAL were not significantly different between septic shock patients with and without AKI. Peak levels of uNGAL were below the upper reference limit in all but four patients without AKI. uNGAL was a good predictor (area under ROC 0.86) whereas pNGAL was a poor predictor (area under ROC 0.67) for AKI within the next 12 h in patients with septic shock. pNGAL is raised in patients with SIRS, severe sepsis, and septic shock and should be used with caution as a marker of AKI in ICU patients with septic shock. uNGAL is more useful in predicting AKI as the levels are not elevated in septic patients without AKI.

Human phospholipase B-precursor (PLB-P) is a newly identified and purified protein from human neutrophils. The precise function of PLB-P in vivo is not yet known. Its existence in neutrophils and the enzymatic activity against phospholipids imply a role in the defence against invading microorganisms and in the generation of lipid mediators of inflammation. We describe here the generation of specific antibodies against PLB-P, the tissue localizations of PLB-P and the establishment of an accurate, specific, and reproducible radioimmunoassay (RIA). A survey of normal and malignant tissues showed strong immunostaining of PLB-P in neuronal and myeloid cells and in adrenal glands. Elevated levels were found in sera of patients with influenza A infection i.e. > 1 mu g/L and in gut fluids of patients with inflammatory bowel disease i.e. > 20 mu g/L. The levels correlated to markets of neutrophil activation, suggesting a neutrophil origin of PLB-P in these conditions. The antibodies and the assay will be useful in the future basic and clinical investigations of PLB-P.

Background and objectives: Several molecular forms of human neutrophil lipocalin/neutrophil gelatinase-associated lipocalin (HNL/NGAL), a novel biomarker for acute kidney injury (AKI), have been found in urine. The origin of these different forms and the effect of antibody configuration on assay performances were investigated in this report. Design, setting, participants, & measurements: The molecular forms of HNL/NGAL from human neutrophils and present in urine obtained from cardiac surgery patients and patients with urinary tract infection (UTI), as well as secreted from HK-2 cells, were studied by Western blotting. The levels of HNL/NGAL in urine were measured by ELISAs. Kidney injury was simulated by incubation of HK-2 cells under stressful conditions. Results: The major molecular form of HNL/NGAL secreted by neutrophils is dimeric, whereas the major form secreted by HK-2 cells is monomeric. This was reflected by a predominance of the monomeric form in urine from patients with AKI and the dimeric form in patients with UTIs. The epitope specificities of the antibody used in the ELISAs had a profound effect on assay performance and paralleled differences of the antibodies to identify the different forms of urine HNL/NGAL. Conclusions: The monomeric form is the predominant form secreted by tubular epithelial cells, and the dimeric form is the predominant form secreted by neutrophils. The development of molecular form-specific assays for HNL/NGAL may be a means to identify the origin of HNL/NGAL in urine and construct more specific tools for the diagnosis of AKI.

BACKGROUND: Acute kidney injury (AKI) is one of the most serious postoperative complications of cardiac surgery. The lack of early and powerful markers for AKI makes the morbidity and mortality still very high. HNL (Human neutrophil lipocalin)/NGAL (Neutrophil gelatinase-associated lipocalin) was recently shown as a novel biomarker for AKI after cardiac surgery. METHODS: Serial urine samples from 59 patients undergoing cardiac surgery were analyzed by polyclonal antibody based radioimmunoassay (RIA), monoclonal-polyclonal antibody based enzyme-linked immunosorbent assay (ELISA). RESULTS: We found 10 to 100-fold increases in urine HNL/NGAL levels in about half of the patients 2 h after termination of the operation and elevated levels in all patients 72 h post operation. The urine levels of HNL/NGAL showed a weak, but significant relation with kidney function as measured by plasma levels of cystatin C or creatinine. The 2 h-HNL/NGAL levels were positively correlated to extracorporeal circulation time (p<0001). The assays were well correlated, but had different clinical performances. CONCLUSIONS: We confirmed that urine HNL/NGAL may be a useful early biomarker of postoperative kidney injury. The results indicate that the antibody configuration of the assay has an impact on the clinical performance of the assay.

A phospholipase B (PLB) precursor was purified from normal human granulocytes using Sephadex G-75, Mono-S cation-exchange and hydroxyapatite columns. The molecular mass of the protein was estimated to be approximately 130 kDa by gel filtration and 22 and 42 kDa by SDS/PAGE. Tryptic peptide and sequence analyses by MALDI-TOF and tandem mass spectrometry (MS/MS) identified the protein as a FLJ22662 (Homo sapiens) gene product, a homologue of the amoeba Dictyostelium discoideum PLB. The native protein needed modifications to acquire deacylation activity against phospholipids including phosphatidylcholine, phosphatidylinositol, phosphatidylethanolamine and lysophospholipids. Enzyme activity was associated with fragments derived from the 42 kDa fragment. The enzyme revealed a PLB nature by removing fatty acids from both the sn-1 and sn-2 positions of phospholipids. The enzyme is active at a broad pH range with an optimum of 7.4. Immunoblotting of neutrophil postnuclear supernatant using antibodies against the 42 kDa fragment detected a band at a molecular mass of 42 kDa, indicating a neutrophil origin of the novel PLB precursor. The existence of the PLB precursor in neutrophils and its enzymatic activity against phospholipids suggest a role in the defence against invading microorganisms and in the generation of lipid mediators of inflammation.

A 75 kDa protein was purified to homogeneity from granule extracts of normal human granulocytes using Sephadex G-75 chromatography, Mono-S cation exchange chromatography and chromatofocusing. The protein consisted of one chain with a molecular mass of 75 kDa, as determined by SDS/PAGE. Tryptic peptide analysis by MALDI-TOF (matrix-assisted laser-desorption ionization-time-of-flight) MS and sequence analysis by MS/MS identified the protein to be N-acetylglucosamine-6-sulphatase (EC 3.1.6.14). The identity of the protein was confirmed by demostrating enzymatic activity towards the substrate N-acetylglucosamine 6-sulphate. The enzyme was active over a broad pH range with an optimum of pH 7.0, and showed a Km value of 13.0 mM and a Vmax value of ~1.8 µM/min per mg. The enzyme also showed O-desulphation activity towards heparan sulphate-derived saccharides. Subcellular fractionation of neutrophil organelles showed the presence of enzymatic activity mainly in the same fractions as primary granules. Furthermore, PMA treatment of the neutrophils induced release of the enzyme, indicating its matrix protein nature. The presence of N-acetylglucosamine-6-sulphatase in human neutrophils implies that neutrophils may play a role in the modulation of cell surface molecules and extracellular matrix by O-desulphation.

The expression of the Fcgamma-receptor I (FcgammaRI), CD64 on normal neutrophils is up-regulated during bacterial infections. CD64 is a promising diagnostic tool in the diagnosis of acute infections. The aim was to study surface expressions of CD64 on neutrophils and monocytes in patients with influenza A with and without complications and evaluate these as diagnostic tools in comparison with serum levels of HNL (human neutrophil lipocalin). CD64 expression on neutrophils and monocytes was evaluated by flow cytometry. HNL was assayed by a specific radioimmunoassay. 22 patients with influenza A with or without complications were included and the results compared with those of 29 patients with acute bacterial infections and 29 healthy subjects. Neutrophil expression of CD64 was increased in influenza A with raised proportion expressing CD64 in complicated compared to uncomplicated influenza. The expression was significantly higher in bacterial infections compared to both influenza groups. Serum levels of HNL were raised in all infection groups, but significantly more so in the group with bacterial infection. ROC-curve analysis showed that neutrophil expression of CD64 and the serum levels of HNL had similar diagnostic power in the discrimination between acute bacterial infections and influenza A. Monocyte expression of CD64 was raised in all infections with no differences between subgroups. We conclude that neutrophil expression of CD64 and serum levels of HNL are both promising assays in the distinction between infections caused by bacteria or influenza A, whereas CD64 could identify patients with complications of their influenza A infection.

The subcellular localization and mobilization of carcinoembryonic antigen-related cell adhesion molecule 8 (CEACAM8) was investigated quantitatively in human neutrophils. In resting neutrophils the majority of CEACAM8 was present in the secondary granules, and a small amount of CEACAM8 was present in a light membrane fraction. Stimulation of the neutrophils with phorbol 12-myristate 13-acetate caused a dramatic increase in the content of CEACAM8 in the light membrane fraction, suggesting a translocation of CEACAM8 to the plasma membrane from intracellular pools. The cellular content of CEACAM8 in the neutrophils was estimated to be 82.4 +/- 8.9 ng/10(6) cells (mean +/- SE, n = 10). Administration of granulocyte colony-stimulating factor (G-CSF) to healthy individuals resulted in an increased content of CEACAM8 in neutrophils on day 1, which decreased on day 4. However, the content of CEACAM8 in the light membrane fraction was increased on day 4, possibly due to the stimulation by induced secondary cytokines, such as tumour necrosis factor-alpha (TNF-alpha). This study establishes the secondary granules as the major intracellular pools of CEACAM8 in human neutrophils, from which it may translocate to the plasma membranes upon stimulation of the cells. The translocation of CEACAM8 seen in vivo after G-CSF administration is probably indirect and caused by cytokines such as TNF-alpha.

Carcinoembryonic antigen-related cell adhesion molecule 8 (CEACAM8), also known as CD66b, NCA-95 and CD67, is a highly glycosylated protein expressed only in neutrophils and eosinophils in humans. The precise function of CEACAM8 remains unclear. As a member of the family of carcinoembryonic antigen (CEA), it may play a role in the interaction between granulocytes or between granulocytes and epithelial cells. We describe here an accurate, specific and reproducible enzyme-linked immunosorbent assay (ELISA) using purified native CEACAM8 as standard for the measurement of CEACAM8 with a detection range of 1-64 microg/l. We also present data on the levels of CEACAM8 in the blood of healthy individuals and patients undergoing surgery, as well as in patients with acute infections. The highly elevated levels of CEACAM8 in the blood of these patients, which are significantly correlated with the surface expression of CEACAM8 on neutrophils and the number of circulating neutrophils, suggest that CEACAM8 could serve as a biological marker for granulocyte activities in vivo.

This paper investigates the problem of H/sub infinity / model reduction for linear discrete-time singular systems. Without decomposing the original system matrices, necessary and sufficient conditions for the solvability of this problem are obtained in terms of linear matrix inequalities (LMIs) and a coupling non-convex rank constraint set. When these conditions are feasible, an explicit parametrization of the desired reduced-order models is given. Particularly, a simple LMI condition without rank constraint is derived for the zeroth-order H/sub infinity / approximation problem. Finally, an illustrative example is provided to demonstrate the applicability of the proposed approach., Anglais

The local release of human neutrophil lipocalin, considered to be highly specific for neutrophil granulocyte activation, and interleukin-8 and tumor necrosis factor-a were studied in 11 patients with distal ulcerative colitis and proctitis before and during treatment with steroid enemas. A rectal perfusion technique for sampling and specific immunoassays for analysis were used. In responders (N = 8) the concentrations of all proteins decreased during the study. There was a close correlation between human neutrophil lipocalin concentrations and treatment response. Tumor necrosis factor-a showed an initial decline in concentrations irrespective of treatment outcome and preceded the decline of human neutrophil lipocalin and interleukin-8. We conclude that decreased neutrophil degranulation is correlated with treatment outcome. Furthermore, an important role of tumor necrosis factor-a in the process of stimulating neutrophil activation and degranulation in ulcerative colitis is suggested.

BACKGROUND AND AIM: Accumulation and infiltration by neutrophil granulocytes is a prominent feature in the local inflammatory process in ulcerative colitis (UC). The present study was performed to evaluate human neutrophil lipocalin (HNL) as a specific neutrophil marker in the inflamed lesions of the colon and rectum in patients with colitis and proctitis. METHODS: The activity of intestinal neutrophils with respect to release of granule proteins was studied in 18 patients with UC (10 with colitis and eight with isolated proctitis) and in 18 healthy controls using perfusion fluid and biopsies from the sigmoid colon and rectum. The released amounts of the neutrophil granule proteins HNL and myeloperoxidase (MPO) were determined by radioimmunoassays, and the location of HNL and MPO in biopsies from colonic mucosa was examined by immunohistochemistry. RESULTS: Mucosal release of HNL and MPO was increased 10-55-fold in patients with colitis and proctitis compared with controls. Their bowel biopsies demonstrated that only neutrophils were stained with anti-HNL. We also found correlations between HNL and levels of granulocyte/macrophage-colony stimulating factor (GM-CSF) and interleukin 8 (IL-8) in perfusion fluids from the sigmoidal segments of patients with proctitis, between HNL and GM-CSF in rectal segments in patients with proctitis, and in sigmoidal segments in patients with colitis. CONCLUSION: We conclude that the increased release of HNL and MPO in colorectal perfusion fluids indicates neutrophil involvement in the local inflammatory process, and suggest that HNL may serve as a specific marker of intestinal neutrophil activation in UC. GM-CSF, and to some extent IL-8, may play a role in neutrophil accumulation and priming in this disease.

A 95-kDa protein was purified to homogeneity from granule extracts of normal human granulocytes. The column procedure consisted of Sephadex G-75, Mono-S cation exchange and Superdex HR 75 chromatography. The purified protein showed only one broad band at a molecular weight of 95 kDa when analyzed by sodium dodecylsulfate-polyacrylamide gel electrophoresis (SDS-PAGE). It reacted with polyclonal antibodies against carcinoembryonic antigen (CEA) and a specific monoclonal antibody against CD66b, but did not react with monoclonal antibodies against CD66acde and CD66c when analyzed by immunoblotting. The molecular weight of the protein shifted from 95 to 40 kDa on SDS-PAGE after deglycosylation. Tryptic peptide analysis by MALDI-Tof identified four peptides with spectra of m/z matching the expected tryptic peptides from a CGM6 gene product. Furthermore, the nanoelectrospray mass spectrometry (MS/MS) analysis of the two selected tryptic peptides of the protein revealed two amino acid sequences corresponding to residues 79-98 and 199-207 of the CGM6 gene product. Based on this, and also on the immunochemical data, it is concluded that the purified 95 kDa is identical to carcinoembryonic antigen-related cell adhesion molecule 8 (CEACAM8) (nonspecific cross-reacting antigen (NCA)-95, CD67 and CD66b) and is a product of the CGM6 (W272) gene. We present, for the first time, a method for the purification of CEACAM8 from normal human granulocytes, which should be useful for further studies on its structure and functions. We also confirmed at the protein level that CEACAM8 is a product of the CGM6 (NCA-W272) gene.