Elevated HbA1c level associated with disease severity and surgical extension in diabetic foot patients.

BACKGROUND: Diabetic foot is a complex syndrome that is associated with other diabetic complications, such as peripheral arte-rial disease and peripheral neuropathy. Optimization of plasma glucose and glycated hemoglobin (HbA1c) is one of the main principles of standard care and treatment approaches in individuals with diabetes mellitus (DM). In this study, the relationship of HbA1c level at the time of diagnosis was evaluated with diabetic foot disease severity score and surgical extension in patients with Type 2 DM. METHODS: This study included 301 consecutive patients who were diagnosed with diabetic foot in the general surgery diabetic foot clinic and were hospitalized for surgery. The relationships between the HbA1c levels of the patients with the Wagner and PEDIS (Perfusion, Extent, Dept, Infection, Sensation) classification system grades, and the surgical procedures performed were analyzed and the treatment outcomes were evaluated. RESULTS: It was determined that there was a 90% statistically significant relationship between HbA1c values of ≥10.1% and the de-velopment of Wagner Grade 4 diabetic foot ulcer (DFU) (P=0.037). A strong statistically significant relationship at the rate of 85% was determined between HbA1c values of ≥10.1% and the development of PEDIS Grade 3 ulcers. As the HbA1c values increased, so there was determined to be a statistically significant relationship with the development of PEDIS Grade 3 ulcer (P=0.003). In the comparison of the HbA1c values according to the type of surgery performed, a weak relationship was determined at the rate of 26%, and it was determined that as the HbA1c values increased, so there could be an increase in the amputation level. CONCLUSION: The results of this study showed that as HbA1c values at diagnosis increased in patients with diabetic foot; Wagner/PEDIS grades, disease severity, surgical extension, amputation level, and tissue loss increased. To reduce the severity of diabetic foot disease and prevent amputation, compliance with diabetic treatment and glycemic control should be increased.

Energy and material refineries of future: Wastewater treatment plants.

There have been many important milestones on humanity's long journey towards achieving environmental sanitation. In particular, the development of the activated sludge system can be claimed to be one of the most groundbreaking advances in the protection of both public health and the wider ecosystem. The first wastewater treatment plants (WWTPs) were developed over a century ago and were soon configured for use with activated sludge. However, despite their long history and service, conventional activated sludge (CAS) plants have become an unsustainable method of wastewater treatment. In addition, conventional WWTPs are intensive energy-consumers and at best allow only very limited material recovery. A paradigm shift to convert existing WWTPs into more sustainable facilities must therefore be considered necessary and to this end the wastewater biorefinery (WWBR) concept may be considered a solution that maximizes both energy and material recovery, in line with the circular economy approach.

Simultaneous use of individual and joint regularization terms in compressive sensing: Joint reconstruction of multi-channel multi-contrast MRI acquisitions.

Multi-contrast images are commonly acquired together to maximize complementary diagnostic information, albeit at the expense of longer scan times. A time-efficient strategy to acquire high-quality multi-contrast images is to accelerate individual sequences and then reconstruct undersampled data with joint regularization terms that leverage common information across contrasts. However, these terms can cause features that are unique to a subset of contrasts to leak into the other contrasts. Such leakage-of-features may appear as artificial tissues, thereby misleading diagnosis. The goal of this study is to develop a compressive sensing method for multi-channel multi-contrast magnetic resonance imaging (MRI) that optimally utilizes shared information while preventing feature leakage. Joint regularization terms group sparsity and colour total variation are used to exploit common features across images while individual sparsity and total variation are also used to prevent leakage of distinct features across contrasts. The multi-channel multi-contrast reconstruction problem is solved via a fast algorithm based on Alternating Direction Method of Multipliers. The proposed method is compared against using only individual and only joint regularization terms in reconstruction. Comparisons were performed on single-channel simulated and multi-channel in-vivo datasets in terms of reconstruction quality and neuroradiologist reader scores. The proposed method demonstrates rapid convergence and improved image quality for both simulated and in-vivo datasets. Furthermore, while reconstructions that solely use joint regularization terms are prone to leakage-of-features, the proposed method reliably avoids leakage via simultaneous use of joint and individual terms, thereby holding great promise for clinical use.

Fast System Calibration With Coded Calibration Scenes for Magnetic Particle Imaging.

Magnetic particle imaging (MPI) is a relatively new medical imaging modality, which detects the nonlinear response of magnetic nanoparticles (MNPs) that are exposed to external magnetic fields. The system matrix (SM) method for MPI image reconstruction requires a time consuming system calibration scan prior to image acquisition, where a single MNP sample is measured at each voxel position in the field-of-view (FOV). The scanned sample has the maximum size of a voxel so that the calibration measurements have relatively poor signal-to-noise ratio (SNR). In this paper, we present the coded calibration scene (CCS) framework, where we place multiple MNP samples inside the FOV in a random or pseudo-random fashion. Taking advantage of the sparsity of the SM, we reconstruct the SM by solving a convex optimization problem with alternating direction method of multipliers using CCS measurements. We analyze the effects of filling rate, number of measurements, and SNR on the SM reconstruction using simulations and demonstrate different implementations of CCS for practical realization. We also compare the imaging performance of the proposed framework with that of a standard compressed sensing SM reconstruction that utilizes a subset of calibration measurements from a single MNP sample. The results show that CCS significantly reduces calibration time while increasing both the SM reconstruction and image reconstruction performances.

Trajectory analysis for field free line magnetic particle imaging.

PURPOSE: Magnetic particle imaging (MPI) is a relatively new method to image the spatial distribution of magnetic nanoparticle (MNP) tracers administered to the body with high spatial and temporal resolution using an inhomogeneous magnetic field. The spatial information of the MNP's is encoded using a field free point (FFP), or a field free line (FFL), in which the magnetic field vanishes at a point, or on a line, respectively. FFL scanning has the advantage of improved sensitivity compared to FFP scanning as a result of higher signal-to-noise ratio. The trajectory traversed by the FFL or FFP is an important parameter of the MPI system and should be selected to achieve the best imaging quality in minimum scan time, while considering hardware constraints and patient safety. In this study, we analyzed the image quality of different FFL trajectories for a large field of view (FOV) using simulations, to provide a baseline information for FFL scanning MPI system design. METHODS: We simulated a human-sized FFL scanning MPI configuration to image a circular FOV with 160 mm diameter, and compared Radial, Spiral, Uniform Spiral, Flower, and Lissajous trajectories with different trajectory densities scanned by the FFL for constant scan time. We analyzed the system matrices of the trajectories in terms of mutual coherence and homogeneity of the spatial sensitivity. We calculated the maximum electric fields induced on a homogeneous conductive body by the selection field (SF) and the focus field (FF) to compare the trajectories based on the nerve stimulation threshold. The images were obtained using the system matrix reconstruction approach with two different image reconstruction methods. In the first one, we used the conventional image reconstruction method, algebraic reconstruction technique (ART), which gives a regularized least-squares solution. In the second one, we used the state-of-the-art alternating direction method of multipliers (ADMM), which minimizes a weighted sum of the l1 -norm and the total variation (TV) of the images. RESULTS: The Radial and Spiral trajectories resulted in a poor imaging performance at low trajectory densities due to relatively high coherency and poor sensitivity of the measurements, respectively. For ART reconstruction, the highest image quality with the lowest trajectory density was achieved with the Uniform Spiral trajectory. Uniform Spiral, Flower, and Lissajous trajectories yielded comparable performance with ADMM reconstruction. The rotating SF induced higher electric field amplitude compared to the FF. Consequently, maximum allowable gradient at the same trajectory density was greater for the Radial trajectory compared to the other trajectories. CONCLUSIONS: For a large FOV coverage, the Uniform Spiral trajectory offers a good compromise between image quality and imaging time, taking safety and hardware limitations into account. The Radial trajectory, especially using l1 -norm and TV priors in the reconstruction, may be favorable in case the SF induced electric field is higher than that of the FF at the same frequency (e.g., relatively small FOV coverage). In general, ADMM reconstruction resulted in higher contrast and resolution compared to ART, leading to lighter requirements on the density of the trajectory.

Statistically Segregated k-Space Sampling for Accelerating Multiple-Acquisition MRI.

A central limitation of multiple-acquisition magnetic resonance imaging (MRI) is the degradation in scan efficiency as the number of distinct datasets grows. Sparse recovery techniques can alleviate this limitation via randomly undersampled acquisitions. A frequent sampling strategy is to prescribe for each acquisition a different random pattern drawn from a common sampling density. However, naive random patterns often contain gaps or clusters across the acquisition dimension that, in turn, can degrade reconstruction quality or reduce scan efficiency. To address this problem, a statistically segregated sampling method is proposed for multiple-acquisition MRI. This method generates multiple patterns sequentially while adaptively modifying the sampling density to minimize k-space overlap across patterns. As a result, it improves incoherence across acquisitions while still maintaining similar sampling density across the radial dimension of k-space. Comprehensive simulations and in vivo results are presented for phase-cycled balanced steady-state free precession and multi-echo [Formula: see text]-weighted imaging. Segregated sampling achieves significantly improved quality in both Fourier and compressed-sensing reconstructions of multiple-acquisition datasets.

Patients' Perspective: What has Changed in Deciding about Breast-Conserving Surgery for Early-Stage Breast Cancer in Turkey?

BACKGROUND: This study aims to describe patients' perception of early breast cancer, factors influencing the choice of operation, patients' sources of information about the disease and the seriousness with which this information is considered, and to address what surgeons can do to enlighten their patients prior to decision-making. METHODS: Patients were asked to complete a questionnaire consisting of 3 sections: The first section addressed influential factors during the decision-making process; the second pertained to the role of surgeons or health facilities in the process; and the third asked patients to revisit their initial choice of surgery. RESULTS: 237 patients were included in the study. Statistical analyzes regarding demographic features showed that nulliparous, younger than 50 years, never or <5 years married, highly educated, business-owning, employed, and stage I breast cancer patients preferred breast-conserving surgery (BCS) to mastectomy. CONCLUSION: Although the rate of BCS is a technical quality indicator for breast cancer centers, providing sufficient patient counseling, involving the patient in the decision-making process, and offering every possible surgical option are key to improving quality of life. Systematic counseling should be provided to breast cancer patients who have primary tumors that are eligible for BCS.

Topical hemostatics for bleeding control in pre-hospital setting: Then and now.

Massive hemorrhage causes instant and early deaths because of hypovolemia. However, even if the victim makes it to the hospital, hypothermia, metabolic acidosis, and coagulation impairments caused by bleeding pose a great risk for survival. Many topical hemostatic agents are developed for neck, armpit, or groin injuries that are not amenable to tourniquet application and for extremity wounds to be used in conjunction with tourniquets. This paper focuses on those hemostatics that differ based on the action mechanism and are suitable for pre-hospital setting and summarizes the latest recommendations regarding their usage.

Bethesda Made It Clearer: A Review of 542 Patients in a Single Institution.

BACKGROUND: It is essential to interpret fine needle aspiration biopsy (FNAB) material correctly to create a common language among pathologists and surgeons, leading to a uniform approach to thyroid nodule management. We aimed to compare FNAB reports of patients at our institution who were treated with total thyroidectomy, before and after the Bethesda classification system. PATIENTS AND METHODS: Patients who underwent total thyroidectomy for thyroid nodules are reviewed. 226 patients who underwent total thyroidectomy before the Bethesda era (2006-2009) were classified as Group-I, and 316 patients in whom total thyroidectomy was performed after the Bethesda classification system was introduced (2010-2014) were classified as Group-II. RESULTS: Before Bethesda, 'nondiagnostic' or 'benign' lesions were reported in 16.4 and 45% of patients, respectively, which then significantly decreased to 4.7 and 32.9% as the Bethesda classification criteria came into use. In Group-II, the actual malignancy rates were 13.3, 2.8, 7.3, 15.5, 85.4, and 96.5% for Bethesda I, II, III, IV, V, and VI, respectively. CONCLUSION: Our experience confirms that the Bethesda classification system leads to a significant reduction in lesions that used to be reported as 'benign' without compromising the actual rates of malignancy. It ensures better classification of so-called suspicious lesions, and allows for more accurate predictions of suspicious or malignant lesions.

The role of calcium entry on the relaxation response of rho-kinase inhibitor in rabbit renal artery.

This study was performed to clarify the role of extracellular and intracellular Ca2+ on rho-kinase enzyme inhibition-induced relaxation in rabbit renal arteries. The response to rho-kinase inhibitor (Y-27632) was studied in isolated renal artery segments precontracted with phenylephrine in the presence of voltage-gated calcium channel blocker nifedipine and in the absence of intracellular or extracellular Ca2+. Cumulative addition of rho-kinase inhibitor Y-27632 (10-8-10-5 M) produced a concentration-dependent relaxation in renal artery rings precontracted with phenylephrine. Preincubation with nifedipine (1µM) resulted in a significant increase in relaxation response to rho-kinase inhibitor Y-27632 compared with preincubation with DMSO; the solvent of nifedipine. The maximal relaxation to Y-27632 in renal arteries precontracted with phenylephrine was significantly increased in the Ca-free Krebs containing 100 µmol/l ethylene glycol tetraacetic acid (EGTA) but after depletion of intracellular stores with 20 mmol/l caffeine and 1mmol/l EGTA in Ca2+ free Krebs there was no significant difference between the relaxation to Y-27632 from control response in 2.5 mmol/l Ca2+ Krebs in the renal artery. These results suggest the involvement of extracellular Ca and L-type voltage-operated Ca2+ channels in phenylephrine-induced rho-kinase activation (Fig. 3, Ref. 20).

Multi-parameter acoustic imaging of uniform objects in inhomogeneous soft tissue.

The problem studied in this paper is ultrasound image reconstruction from frequency-domain measurements of the scattered field from an object with contrast in attenuation and sound speed. The case in which the object has uniform but unknown contrast in these properties relative to the background is considered. Background clutter is taken into account in a physically realistic manner by considering an exact scattering model for randomly located small scatterers that vary in sound speed. The resulting statistical characteristics of the interference are incorporated into the imaging solution, which includes application of a total-variation minimization-based approach in which the relative effect of perturbation in sound speed to attenuation is included as a parameter. Convex optimization methods provide the basis for the reconstruction algorithm. Numerical data for inversion examples are generated by solving the discretized Lippman-Schwinger equation for the object and speckle-forming scatterers in the background. A statistical model based on the Born approximation is used for reconstruction of the object profile. Results are presented for a two-dimensional problem in terms of classification performance and compared with minimum-l2-norm reconstruction. Classification using the proposed method is shown to be robust down to a signal-to-clutter ratio of less than 1 dB.

Venous thromboembolism risk and thromboprophylaxis among hospitalized patients: data from the Turkish arm of the ENDORSE study.

OBJECTIVES: To evaluate venous thromboembolism (VTE) risk and use of thromboprophylaxis in the acute care hospital setting. METHODS: A total of 1701 patients hospitalized for acute or exacerbated chronic medical illnesses or elective major surgery at 11 different hospitals across Turkey were included in the study. Patients at risk and VTE prophylaxis application were retrospectively identified based on medical charts. RESULTS: According to the American College of Chest Physicians (ACCP) criteria, overall 35.6% (606 of 1701) of the patients were identified to be at VTE risk. Venous thromboembolism-risk was observed in 64.9% of surgical and 23.8% of medical patients, the latter being lower than global Epidemiologic International Day for the Evaluation of Patients at Risk for Venous Thromboembolism in the Acute Hospital Care Setting (ENDORSE) study results; while prophylaxis was prescribed in 39.0% and 38.5% of them, respectively. Contraindication to anticoagulant prophylaxis was observed in 8.7% of medical and 8.8% of surgical patients. CONCLUSIONS: VTE remains a risk factor among patients hospitalized across Turkey, since identification as well as prophylaxis of patients at VTE risk seems to be neglected.

Evaluation of vascular smooth muscle and corpus cavernosum on hypercholesterolemia. Is resveratrol promising on erectile dysfunction?

The aim of this study is to evaluate the effects of hypercholesterolemia in thoracic aorta (TA), mesenteric artery (MA), renal artery (RA), and corpus cavernosum (CC) isolated from cholesterol-fed rabbits. For determination of the maximum detrimental effect, vasorelaxation and vasoconstriction results of arteries and CC have been compared. Animals were fed with a diet that contained 2% w/w cholesterol and 2% w/w high cholesterol plus resveratrol (4 mg kg(-1) per day) for 6-week duration. Total cholesterol levels in the plasma were measured. Vascular and endothelial functions in RA, TA, MA, and CC were assessed by isolated tissue bath with cumulative doses of acetylcholine and sodium nitroprusside. The statistical significance of differences of groups was analyzed by means of one-way ANOVA or Student's t-test. P-values <0.05 were considered significant. There have been no significant changes on plasma total cholesterol levels between cholesterol and cholesterol + resveratrol-treated groups. Vasorelaxation responses to acetylcholine in resveratrol-treated group showed significant changes when compared with hypercholesterolemic group. No statistically significant differences were seen between non-receptor-mediated vasorelaxation responses between the three groups. Resveratrol might be an effective treatment in the prevention of atherosclerotic changes in arteries and CC. The initial effects of hypercholesterolemia on erectile dysfunction and endothelial dysfunction may be precluded with resveratrol. This protective effect may also ensure the prevention of coronary arterial diseases and renovascular diseases in hypercholesterolemic patients.

Fast computation of the acoustic field for ultrasound elements.

A fast method for computing the acoustic field of ultrasound transducers is presented with application to rectangular elements that are cylindrically focused. No closed-form solutions exist for this case but several numerical techniques have been described in the ultrasound imaging literature. Our motivation is the rapid calculation of imaging kernels for physics-based diagnostic imaging for which current methods are too computationally intensive. Here, the surface integral defining the acoustic field from a baffled piston is converted to a 3-D spatial convolution of the element surface and the Green's function. A 3-D version of the overlap-save method from digital signal processing is employed to obtain a fast computational algorithm based on spatial Fourier transforms. Further efficiency is gained by using a separable approximation to the Green's function through singular value decomposition and increasing the effective sampling rate by polyphase filtering. The tradeoff between accuracy and spatial sampling rate is explored to determine appropriate parameters for a specific transducer. Comparisons with standard tools such as Field II are presented, where nearly 2 orders of magnitude improvement in computation speed is observed for similar accuracy.

B-type natriuretic peptide as an indicator of right ventricular dysfunction in acute pulmonary embolism.

OBJECTIVE: B-type natriuretic peptide (BNP) is a neurohormone secreted from cardiac ventricles in response to ventricular strain. The aim of present study was to evaluate the role of BNP in the diagnosis of the right ventricular (RV) dysfunction in acute pulmonary embolism (PE). METHODS: BNP levels were measured in patients with acute PE as diagnosed by high probability lung scan or positive spiral computed tomography. All patients underwent standard echocardiography and blood tests during the second hour of the diagnosis. RESULTS: Forty patients diagnosed as acute PE (mean age, 60.4 +/- 13.2 years; 62.5% women) were enrolled in this study. Patients with RV dysfunction had significantly higher BNP levels than patients without RV dysfunction (426 +/- 299.42 pg/ml vs. 39.09 +/- 25.22 pg/ml, p < 0.001). BNP-discriminated patients with or without RV dysfunction (area under the receiver operating characteristic curve, 0.943; 95% CI, 0.863-1.022). BNP > 90 pg/ml was associated with a risk ratio of 165 (95% CI, 13.7-1987.2) for the diagnosis of RV dysfunction. There was a significant correlation between RV end-diastolic diameter and BNP (r = 0.89, p < 0.001). Sixteen patients (40%) were diagnosed as having low-risk PE, 19 patients (47.5%) with submassive PE and five patients (12.5%) with massive PE. The mean BNP was 39.09 +/- 25.2, 378.4 +/- 288.4 and 609.2 +/- 279.2 pg/ml in each group respectively. CONCLUSION: Measurement of BNP levels may be a useful approach in diagnosis of RV dysfunction in patients with acute PE. The possibility of RV dysfunction in patients with plasma BNP levels > 90 pg/ml should be strongly considered.

Vasorelaxant effect of iloprost on isolated human internal mammary artery.

In this study, vasodilator effect of iloprost on KCl-induced contraction in human internal mammary artery (IMA) was studied and compared with other vasodilators papaverin and diltiazem. Ring segments of IMA were studied in organ baths for measurement of isometric tension. After the tissues has reached their baseline tension, precontraction was induced by 100 mm KCl and cumulative concentration-relaxation was measured by the application of iloprost (10(-9)-10(-6) m), papaverine (10(-5)-10(-4) m), diltiazem (10(-9)-10(-4) m) or ethanol; a solvent for iloprost; alone. The maximal relaxation of IMA segments to iloprost was 13.5 +/- 2.2%. Iloprost caused significantly limited relaxation when compared with papaverin (106.0 +/- 2.9%) and diltiazem (93.6 +/- 2.5%) (P < 0.001). Papaverin produced the greatest maximal relaxation to KCl-induced contraction of IMA. The potency of iloprost (-log EC(50) = 6.59 +/- 0.19) was significantly higher than those of papaverine (-log EC(50) = 4.21 +/- 0.11) and diltiazem (-log EC(50) = 5.63 +/- 0.06) (P < 0.001). In addition, -log EC(50) of diltiazem was significantly greater than papaverin (P < 0.001). Iloprost appears to be more potent than those of papaverine and diltiazem but it was inefficient in maximal inhibition on KCl-induced contraction. Iloprost may have little benefit in KCl-related vasoconstriction on human IMA segments.

Clinical importance of preoperative detection of the apical lymph node metastasis in patients with breast carcinoma.

INTRODUCTION: According to the revised staging system for breast cancer, the infraclavicular node status has become more important because the involvement of the apical nodes now changes the stage of the disease for all tumour sizes. In this study, we analysed the stage migration among our patients treated with mastectomy for breast cancer. METHODS: 44 patients who were treated with modified radical mastectomy for breast cancer in our department during 2003 were reviewed for their clinicopathological features, including the status of the axillary lymph nodes. RESULTS: 11 patients (25 percent) were reclassified as stage IIIC according to the new Tumour, Node and Metastasis (TNM) classification system of American Joint Committee on Cancer that was revised in 2002. The mean age was 40.2 years and the mean tumour size was 5 cm. CONCLUSION: Patients with breast cancer should be properly staged preoperatively for choosing appropriate individual treatment, and more accurate evaluation of the infraclavicular region for metastatic lymph nodes should be done.

Liver enzyme alterations after laparoscopic cholecystectomy.

AIMS: We aimed to investigate the alterations in serum levels of alanine aminotransferase (ALT), aspartate aminotransferase (AST), gamma-glutamyl-transferase (GGT), alkaline phosphatase (ALP) and lactate dehydrogenase (LDH) in patients who had undergone laparoscopic cholecystectomy (LC) and compare these changes with those occurring after open cholecystectomy (OC). METHODS: Of 267 patients who underwent LC between January 2003 and December 2005, 86 patients without complications were eligible for study. Twenty-six patients who underwent OC during the same interval were also enrolled in the study as a control group. Blood samples were taken preoperatively and 24 hours after operation for biochemical tests. RESULTS: Statistical analyses revealed significant increases in AST, ALT, GGT and LDH levels in the LC group postoperatively. Compared with the OC group, the differences between elevations of enzyme levels were also significant for LC group. CONCLUSION: We conclude that these enzyme elevations could mostly be attributed to the negative effects of the pneumoperitoneum on the hepatic blood flow. Although these changes do not seem to be clinically important, care should be taken before deciding to perform LC in patients with hepatic insufficiency.

Granulomatous mastitis: surgical outcomes.

OBJECTIVE: To report the clinical and pathological features and surgical treatment outcomes of patients with granulomatous mastitis. DESIGN: Case series. PLACE AND DURATION OF STUDY: Ankara Oncology Training and Research Hospital, between 1999-2003. PATIENTS AND METHODS: Data of 16 patients with granulomatous mastitis treated surgically by total excision with disease-free margins were reviewed. Patients given additional medical therapy or treated with mastectomy because of the size and extent of the disease were excluded. RESULTS: The mean age of patients at the time of diagnosis was 31.8 (range: 22-45 years). All patients were diagnosed from the pathological tissue specimens obtained by surgery. Clinical and radiological examinations suggested breast carcinoma in 82.1% patients. Except one patient who developed a fistula from the incision which was treated again with surgery, no other complications were noted, including recurrence of disease during a median follow-up period of 12.8 months (range: 4-30 months). CONCLUSION: Although granulomatous mastitis is a rare benign breast disease, it usually mimics breast carcinoma both clinically and radiologically, making the diagnosis difficult and challenging. As long as good cosmetic results can be achieved, surgical excision is quick, safe and effective treatment method for idiopathic granulomatous mastitis.

Evaluation of ex vivo expanded human NK cells on antileukemia activity in SCID-beige mice.

The possibility of using natural killer (NK) cells in treatment of human hematological malignancies has increased in recent years. One factor contributing to this is the introduction of new methods for ex vivo generation of enriched populations of clinical grade NK cells. The objective of the present study was to evaluate the safety and efficacy of human ex vivo expanded clinical grade NK cells against K562 leukemia cells in severe combined immunodeficiency disease (SCID)-beige mice. Irradiated SCID-beige mice were injected intravenously (i.v.) with K562 leukemia cells. Following leukemia cell injection, mice were injected with ex vivo expanded human NK cells. NK cells were followed in vivo and mice monitored for survival from leukemia. Administration of these ex vivo expanded clinical grade NK cells was safe and prevented leukemia development. In conclusion, these results imply possibilities for the use of this NK cell preparation in treatment trials of human hematological malignancies and possibly other forms of cancer.