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1.
Cells ; 8(11)2019 10 24.
Article in English | MEDLINE | ID: mdl-31653091

ABSTRACT

Glioblastoma (GBM) is the most common astrocytic-derived brain tumor in adults, characterized by a poor prognosis mainly due to the resistance to the available therapy. The study of mitochondria-derived oxidative stress, and of the biological events that orbit around it, might help in the comprehension of the molecular mechanisms at the base of GBM responsiveness to Temozolomide (TMZ). Sensitive and resistant GBM cells were used to test the role of mitochondrial ROS release in TMZ-resistance. Chaperone-Mediated Autophagy (CMA) activation in relation to reactive oxygen species (ROS) release has been measured by monitoring the expression of specific genes. Treatments with H2O2 were used to test their potential in reverting resistance. Fluctuations of cytoplasmic ROS levels were accountable for CMA induction and cytotoxic effects observed in TMZ sensitive cells after treatment. On the other hand, in resistant cells, TMZ failed in producing an increase in cytoplasmic ROS levels and CMA activation, preventing GBM cell toxicity. By increasing oxidative stress, CMA activation was recovered, as also cell cytotoxicity, especially in combination with TMZ treatment. Herein, for the first time, it is shown the relation between mitochondrial ROS release, CMA activation and TMZ-responsiveness in GBM.


Subject(s)
Chaperone-Mediated Autophagy/physiology , Glioblastoma/metabolism , Oxidative Stress/physiology , Apoptosis , Autophagy/drug effects , Autophagy/physiology , Brain Neoplasms/genetics , Cell Line, Tumor , Chaperone-Mediated Autophagy/drug effects , Cytoplasm/metabolism , Drug Resistance, Neoplasm/genetics , Glioblastoma/drug therapy , Humans , Hydrogen Peroxide , Mitochondria/metabolism , Oxidation-Reduction , Reactive Oxygen Species/metabolism , Signal Transduction , Temozolomide/metabolism , Temozolomide/pharmacology
2.
J Nucl Cardiol ; 26(3): 775-785, 2019 06.
Article in English | MEDLINE | ID: mdl-29043555

ABSTRACT

AIM: To evaluate the impact of non-specific normal databases on the percent summed rest score (SR%) and stress score (SS%) from simulated low-dose SPECT studies by shortening the acquisition time/projection. METHODS: Forty normal-weight and 40 overweight/obese patients underwent myocardial studies with a conventional gamma-camera (BrightView, Philips) using three different acquisition times/projection: 30, 15, and 8 s (100%-counts, 50%-counts, and 25%-counts scan, respectively) and reconstructed using the iterative algorithm with resolution recovery (IRR) AstonishTM (Philips). Three sets of normal databases were used: (1) full-counts IRR; (2) half-counts IRR; and (3) full-counts traditional reconstruction algorithm database (TRAD). The impact of these databases and the acquired count statistics on the SR% and SS% was assessed by ANOVA analysis and Tukey test (P < 0.05). RESULTS: Significantly higher SR% and SS% values (> 40%) were found for the full-counts TRAD databases respect to the IRR databases. For overweight/obese patients, significantly higher SS% values for 25%-counts scans (+19%) are confirmed compared to those of 50%-counts scan, independently of using the half-counts or the full-counts IRR databases. CONCLUSIONS: AstonishTM requires the adoption of the own specific normal databases in order to prevent very high overestimation of both stress and rest perfusion scores. Conversely, the count statistics of the normal databases seems not to influence the quantification scores.


Subject(s)
Coronary Artery Disease/diagnostic imaging , Myocardial Perfusion Imaging , Tomography, Emission-Computed, Single-Photon , Aged , Algorithms , Coronary Artery Disease/complications , Databases, Factual , Female , Gamma Cameras , Humans , Image Processing, Computer-Assisted , Male , Middle Aged , Obesity/complications , Radiopharmaceuticals
3.
Front Oncol ; 8: 249, 2018.
Article in English | MEDLINE | ID: mdl-30013951

ABSTRACT

RATIONALE: The activity of the transcription factor, hypoxia-inducible factor (HIF)-1α, is a common driver of a number of the pathways involved in the aggressiveness of glioblastomas (GBMs), and it has been suggested that the reduction in this activity observed, soon after the administration of temozolomide (TMZ), can be a biomarker of an early response in GBM models. As HIF-1α is a tightly regulated protein, studying the processes involved in its downregulation could shed new light on the mechanisms underlying GBM sensitivity or resistance to TMZ. METHODS: The effect of HIF-1α silencing on cell responsiveness to TMZ was assessed in four genetically different human GBM cell lines by evaluating cell viability and apoptosis-related gene balance. LAMP-2A silencing was used to evaluate the contribution of chaperone-mediated autophagy (CMA) to the modulation of HIF-1α activity in TMZ-sensitive and TMZ-resistant cells. RESULTS: The results showed that HIF-1α but not HIF-2α activity is associated with GBM responsiveness to TMZ: its downregulation improves the response of TMZ-resistant cells, while blocking CMA-mediated HIF-1α degradation induces resistance to TMZ in TMZ-sensitive cells. These findings are in line with the modulation of crucial apoptosis-related genes. CONCLUSION: Our results demonstrate the central role played by HIF-1α activity in determining the sensitivity or resistance of GBMs to TMZ, and we suggest that CMA is the cellular mechanism responsible for modulating this activity after TMZ treatment.

4.
Front Immunol ; 9: 1186, 2018.
Article in English | MEDLINE | ID: mdl-29896202

ABSTRACT

Tumor microenvironment is fundamental for cancer progression and chemoresistance. Among stromal cells tumor-associated macrophages (TAMs) represent the largest population of infiltrating inflammatory cells in malignant tumors, promoting their growth, invasion, and immune evasion. M2-polarized TAMs are endowed with the nitric oxide (NO)-generating enzyme inducible nitric oxide synthase (iNOS). NO has divergent effects on tumors, since it can either stimulate tumor cells growth or promote their death depending on the source of it; likewise the role of iNOS in cancer differs depending on the cell type. The role of NO generated by TAMs has not been investigated. Using different tumor models in vitro and in vivo we found that NO generated by iNOS of M2-polarized TAMs is able to protect tumor cells from apoptosis induced by the chemotherapeutic agent cisplatin (CDDP). Here, we demonstrate that the protective effect of NO depends on the inhibition of acid sphingomyelinase (A-SMase), which is activated by CDDP in a pathway involving the death receptor CD95. Mechanistic insights indicate that NO actions occur via generation of cyclic GMP and activation of protein kinase G (PKG), inducing phosphorylation of syntaxin 4 (synt4), a SNARE protein responsible for A-SMase trafficking and activation. Noteworthy, phosphorylation of synt4 at serine 78 by PKG is responsible for the proteasome-dependent degradation of synt4, which limits the CDDP-induced exposure of A-SMase to the plasma membrane of tumor cells. This inhibits the cytotoxic mechanism of CDDP reducing A-SMase-triggered apoptosis. This is the first demonstration that endogenous NO system is a key mechanism through which TAMs protect tumor cells from chemotherapeutic drug-induced apoptosis. The identification of the pathway responsible for A-SMase activity downregulation in tumors leading to chemoresistance warrants further investigations as a means to identify new anti-cancer molecules capable of specifically inhibiting synt4 degradation.


Subject(s)
Cisplatin/pharmacology , Drug Resistance, Neoplasm/immunology , Glioma/immunology , Macrophages/immunology , Neoplasm Proteins/immunology , Nitric Oxide/immunology , Qa-SNARE Proteins/immunology , Sphingomyelin Phosphodiesterase/immunology , Animals , Cell Line, Tumor , Drug Resistance, Neoplasm/drug effects , Drug Resistance, Neoplasm/genetics , Glioma/drug therapy , Glioma/genetics , Glioma/pathology , Humans , Macrophages/pathology , Mice , Mice, Knockout , Neoplasm Proteins/genetics , Nitric Oxide/genetics , Nitric Oxide Synthase Type II/genetics , Nitric Oxide Synthase Type II/immunology , Qa-SNARE Proteins/genetics , Sphingomyelin Phosphodiesterase/genetics
5.
Phys Med ; 41: 109-116, 2017 Sep.
Article in English | MEDLINE | ID: mdl-28343906

ABSTRACT

New technologies are available in myocardial perfusion imaging. They include new software that recovers image resolution and limits image noise, multifocal collimators and dedicated cardiac cameras in which solid-state detectors are used and all available detectors are constrained to imaging just the cardiac field of view. These innovations resulted in shortened study times or reduced administered activity to patients, while preserving image quality. Many single center and some multicenter studies have been published during the introduction of these innovations in the clinical practice. Most of these studies were lead in the framework of "agreement studies" between different methods of clinical measurement. They aimed to demonstrate that these new software/hardware solutions allow the acquisition of images with reduced acquisition time or administered activity with comparable results (as for image quality, image interpretation, perfusion defect quantification, left ventricular volumes and ejection fraction) to the standard-time or standard-dose SPECT acquired with a conventional gamma camera and reconstructed with the traditional FBP method, considered as the gold standard. The purpose of this review is to provide the reader with a comprehensive understanding of the pro and cons of the different approaches summarizing the achievements reached so far and the issues that need further investigations.


Subject(s)
Algorithms , Myocardial Perfusion Imaging , Gamma Cameras , Humans , Radiographic Image Enhancement , Software , Tomography, Emission-Computed, Single-Photon
6.
J Nucl Cardiol ; 24(3): 876-887, 2017 06.
Article in English | MEDLINE | ID: mdl-26911365

ABSTRACT

BACKGROUND: The introduction of a camera-based dose-reduction strategy in myocardial perfusion imaging (MPI) clinical setting entails the definition of objective and reproducible criteria for establishing the amount of activity to be injected. AIM: The aim is to evaluate the impact of count statistics on the estimation of summed-scores (SS), end-diastolic volume (EDV), end-systolic volume (ESV), and ejection fraction (EF). METHODS: Data rest/stress ECG-gated SPECT (2-day protocol and 8 MBq·kg-1) were acquired with Bright View gamma camera and Astonish algorithm for 40 normal-weight and 40 overweight patients. Assuming that count statistics of shorter acquisition time may simulate that of lower injected activity, three simultaneous scans (full-time, half-time, and quarter-time scans) were started at the same time but with different acquisition time/projection (30, 15 and 8 seconds). RESULTS: A significant difference between SS values of half-time and quarter-time stress scans was found for overweight group (P = .006). Post hoc test showed significant differences for ESV (P < .05), EDV (P < .01) and EF (P < .05) between half-time and quarter-time scans for both patient groups. CONCLUSIONS: The reduction of the count-statistics to a quarter of the MPI reference influenced negatively the quantification in overweight patients. The decrease of radiopharmaceutical activity to 25% of the reference seems practicable for normal-weight patients, while it is more appropriate an activity reduction limited to 50% for overweight and obese patients.


Subject(s)
Cardiac-Gated Single-Photon Emission Computer-Assisted Tomography/methods , Coronary Artery Disease/diagnostic imaging , Image Interpretation, Computer-Assisted/methods , Obesity/diagnostic imaging , Organophosphorus Compounds/administration & dosage , Organotechnetium Compounds/administration & dosage , Radiation Exposure/analysis , Radiation Exposure/prevention & control , Aged , Female , Humans , Image Enhancement/methods , Male , Myocardial Perfusion Imaging , Radiation Protection/methods , Radiopharmaceuticals/administration & dosage , Reproducibility of Results , Sensitivity and Specificity , Stroke Volume
7.
J Nucl Cardiol ; 24(5): 1626-1636, 2017 10.
Article in English | MEDLINE | ID: mdl-27233252

ABSTRACT

BACKGROUND: New technologies are available in MPI. Our aim was to evaluate their impact on the uniformity of normal myocardial uptake in the polar-map representation, over different count statistics, with and without the attenuation (AC) and scatter corrections (SC). METHODS: A phantom study was performed using 5 Anger gamma cameras with filtered back projection or iterative reconstruction with resolution recovery (IRR), with or without SCAC; a D530c, with or without AC; and a D-SPECT. Count statistics ranged up to a quarter of the reference for the conventional gamma cameras and up to one half for the advanced scanners. Using polar maps, the segmental uptakes and their uncertainties, the 'global uniformity' of polar maps expressed as the coefficient of variation (COV) among the segmental uptakes and the anterior/inferior (ANT/INF) ratio were calculated. RESULTS: Both segmental uptakes and their uncertainties did not depend on the count statistics in the range studied. An increase in the segmental uptakes was found from IRR to IRR + SCAC (78.0% ± 13.5% vs 86.1% ± 9.4%; P < .0001). COV was lower for D-SPECT (10.1% ± 0.5%) and after SCAC for both conventional (9.9% ± 3.0%) and advanced systems (8.9% ± 1.7%). The ANT/INF ratio was above 1 for IRR (1.12 ± 0.07) and fell slightly below 1 for IRR + SCAC (0.97 ± 0.05). CONCLUSIONS: To compare data from the analysis of polar maps across different systems will require the adoption of specific normality databases, developed for each system and reconstruction method employed.


Subject(s)
Heart/diagnostic imaging , Myocardial Perfusion Imaging/methods , Myocardial Perfusion Imaging/trends , Tomography, Emission-Computed, Single-Photon , Algorithms , Anthropometry , Gamma Cameras , Humans , Image Processing, Computer-Assisted , Myocardium/pathology , Phantoms, Imaging , Radionuclide Imaging , Software
8.
Clin Nucl Med ; 41(12): e522-e524, 2016 Dec.
Article in English | MEDLINE | ID: mdl-27824327

ABSTRACT

Urinary clearance of F-FDG and variability in bladder wall FDG uptake may hamper the interpretation and limit the use of FDG-PET/CT for imaging bladder tumors. Nevertheless, careful combined evaluation of both CT and FDG-PET images of the urinary tract can provide useful findings. We present 2 cases of bladder cancer detected by FDG-PET/CT. These cases suggest that FDG uptake can be indicative of malignancy in bladder cancer when viewed in conjunction with CT scans and that whole-body FDG-PET/CT scans should always be reviewed with particular attention to the urinary tract because abnormalities suggestive of bladder cancer can be found unexpectedly.


Subject(s)
Fluorodeoxyglucose F18 , Positron Emission Tomography Computed Tomography , Radiopharmaceuticals , Urinary Bladder Neoplasms/diagnostic imaging , Humans , Male , Middle Aged
9.
Cancer Cell ; 30(2): 257-272, 2016 08 08.
Article in English | MEDLINE | ID: mdl-27505672

ABSTRACT

Hypoxia is a universal driver of aggressive tumor behavior, but the underlying mechanisms are not completely understood. Using a phosphoproteomics screen, we now show that active Akt accumulates in the mitochondria during hypoxia and phosphorylates pyruvate dehydrogenase kinase 1 (PDK1) on Thr346 to inactivate the pyruvate dehydrogenase complex. In turn, this pathway switches tumor metabolism toward glycolysis, antagonizes apoptosis and autophagy, dampens oxidative stress, and maintains tumor cell proliferation in the face of severe hypoxia. Mitochondrial Akt-PDK1 signaling correlates with unfavorable prognostic markers and shorter survival in glioma patients and may provide an "actionable" therapeutic target in cancer.


Subject(s)
Cellular Reprogramming/physiology , Mitochondria/metabolism , Neoplasms/metabolism , Neoplasms/pathology , Proto-Oncogene Proteins c-akt/metabolism , Animals , Cell Hypoxia/physiology , Cell Line, Tumor , Cell Proliferation/physiology , Female , Humans , Male , Mice , Mice, Inbred NOD , Mice, Nude , Protein Serine-Threonine Kinases/metabolism , Pyruvate Dehydrogenase Acetyl-Transferring Kinase , Signal Transduction
10.
Oncotarget ; 7(30): 48753-48787, 2016 Jul 26.
Article in English | MEDLINE | ID: mdl-27145373

ABSTRACT

Cancer is a complex disease, characterized by alteration of different physiological molecular processes and cellular features. Keeping this in mind, the possibility of early identification and detection of specific tumor biomarkers by non-invasive approaches could improve early diagnosis and patient management.Different molecular imaging procedures provide powerful tools for detection and non-invasive characterization of oncological lesions. Clinical studies are mainly based on the use of computed tomography, nuclear-based imaging techniques and magnetic resonance imaging. Preclinical imaging in small animal models entails the use of dedicated instruments, and beyond the already cited imaging techniques, it includes also optical imaging studies. Optical imaging strategies are based on the use of luminescent or fluorescent reporter genes or injectable fluorescent or luminescent probes that provide the possibility to study tumor features even by means of fluorescence and luminescence imaging. Currently, most of these probes are used only in animal models, but the possibility of applying some of them also in the clinics is under evaluation.The importance of tumor imaging, the ease of use of optical imaging instruments, the commercial availability of a wide range of probes as well as the continuous description of newly developed probes, demonstrate the significance of these applications. The aim of this review is providing a complete description of the possible optical imaging procedures available for the non-invasive assessment of tumor features in oncological murine models. In particular, the characteristics of both commercially available and newly developed probes will be outlined and discussed.


Subject(s)
Biomarkers, Tumor/metabolism , Early Detection of Cancer/methods , Fluorescent Dyes/administration & dosage , Luminescent Measurements/methods , Molecular Imaging/methods , Neoplasms/diagnostic imaging , Optical Imaging/methods , Animals , Genes, Reporter/genetics , Humans , Magnetic Resonance Imaging/methods , Neoplasms/metabolism , Neoplasms/pathology , Neoplasms, Experimental/diagnostic imaging , Optical Imaging/instrumentation , Sensitivity and Specificity , Staining and Labeling/methods
12.
PLoS One ; 11(1): e0146622, 2016.
Article in English | MEDLINE | ID: mdl-26795765

ABSTRACT

INTRODUCTION: Dendritic cells play a key role as initiators of T-cell responses, and even if tumour antigen-loaded dendritic cells can induce anti-tumour responses, their efficacy has been questioned, suggesting a need to enhance immunization strategies. MATHERIALS & METHODS: We focused on the characterization of bone marrow-derived dendritic cells pulsed with whole tumour lysate (TAA-DC), as a source of known and unknown antigens, in a mouse model of breast cancer (MMTV-Ras). Dendritic cells were evaluated for antigen uptake and for the expression of MHC class I/II and costimulatory molecules and markers associated with maturation. RESULTS: Results showed that antigen-loaded dendritic cells are characterized by a phenotypically semi-mature/mature profile and by the upregulation of genes involved in antigen presentation and T-cell priming. Activated dendritic cells stimulated T-cell proliferation and induced the production of high concentrations of IL-12p70 and IFN-γ but only low levels of IL-10, indicating their ability to elicit a TH1-immune response. Furthermore, administration of Antigen loaded-Dendritic Cells in MMTV-Ras mice evoked a strong anti-tumour response in vivo as demonstrated by a general activation of immunocompetent cells and the release of TH1 cytokines. CONCLUSION: Data herein could be useful in the design of antitumoral DC-based therapies, showing a specific activation of immune system against breast cancer.


Subject(s)
Antigen Presentation/immunology , Cancer Vaccines/pharmacology , Dendritic Cells/immunology , Immunotherapy/methods , Neoplasms/therapy , Tissue Extracts/pharmacology , Animals , Antigen Presentation/genetics , Antigens, Neoplasm/immunology , Cancer Vaccines/immunology , Cell Proliferation/physiology , Cells, Cultured , Female , Histocompatibility Antigens Class I/biosynthesis , Histocompatibility Antigens Class II/biosynthesis , Interferon-gamma/biosynthesis , Interleukin-10/biosynthesis , Interleukin-12/biosynthesis , Lymphocyte Activation/immunology , Male , Mice , Neoplasms/immunology , Neoplasms/metabolism , T-Lymphocytes, Cytotoxic/immunology , Th1 Cells/immunology
13.
Radiat Prot Dosimetry ; 168(3): 337-42, 2016 Mar.
Article in English | MEDLINE | ID: mdl-25994847

ABSTRACT

Given the large number of [(18)F]fluorodeoxyglucose (FDG) PET examinations performed annually throughout the world, reduction of the administered activity without compromise of the clinical information being sought is encouraged. Guidelines issued by the SNMMI and European Association of Nuclear Medicine (EANM) differ greatly on the choice of the activity that should be administered to patients: the EANM suggests a personalised activity based on the patient's body weight, whereas the SNMMI recommends the administration of fixed activities. The authors analysed a database of 24 716 [(18)F]FDG administrations performed worldwide in 15 PET centres to assess the degree of heterogeneity, in relation to available technology, operational protocols and reference guidelines. Median activities based on the patients' body weight were 43 % lower than fixed-activity administrations (p < 0.001). When TOF scanners are available, the median activity is lowered, but when comparing centres with the same technology or those that use the same operational protocols, weight-based activities are still significantly lower than fixed activities.


Subject(s)
Fluorodeoxyglucose F18/administration & dosage , Health Care Surveys , Positron-Emission Tomography/methods , Positron-Emission Tomography/standards , Practice Guidelines as Topic/standards , Radiopharmaceuticals/administration & dosage , Communicable Diseases/diagnostic imaging , Humans , Inflammation/diagnostic imaging , International Agencies , Neoplasms/diagnostic imaging , Nuclear Medicine
14.
Mol Imaging ; 142015.
Article in English | MEDLINE | ID: mdl-26044881

ABSTRACT

The main scientific issue hindering the development of tissue engineering technologies is the lack of proper vascularization. Among the various approaches developed for boosting vascularization, scaffold design has attracted increasing interest over the last few years. The aim of this article is to illustrate a scaffold design strategy for enhancing vascularization based on sacrificial microfabrication of embedded microchannels. This approach was combined with an innovative poly(ether urethane urea) (PEUtU) porous scaffold to provide an alternative graft substitute material for the treatment of tissue defects. Fluorescent and chemiluminescent imaging combined with computed tomography were used to study the behavior of the scaffold composition within living subjects by analyzing angiogenesis and inflammation processes and observing the variation in x-ray absorption, respectively. For this purpose, an IntegriSense 680 probe was used in vivo for the localization and quantification of integrin αvß3, due to its critical involvement in angiogenesis, and a XenoLight RediJect Inflammation Probe for the study of the decline in inflammation progression during healing. Overall, the collected data suggest the advantages of embedding a synthetic vascular network into a PEUtU porous matrix to enhance in vivo tissue integration, maturation, and regeneration. Moreover, our imaging approach proved to be an efficient and versatile tool for scaffold in vivo testing.


Subject(s)
Diagnostic Imaging/methods , Neovascularization, Physiologic , Tissue Scaffolds/chemistry , Animals , Female , Inflammation/pathology , Mechanical Phenomena , Mice , Porosity , Tomography, X-Ray Computed
15.
Clin Nucl Med ; 40(1): 32-5, 2015 Jan.
Article in English | MEDLINE | ID: mdl-25290294

ABSTRACT

INTRODUCTION: Although parkinsonism is considered a core feature of dementia with Lewy bodies (DLB), it is occasionally mild or even absent. I-FP-CIT SPECT has been accepted as a diagnostic support tool in this context, given that low striatal uptake is associated with neuronal loss. The aim of this retrospective study was to look for correlations between I-FP-CIT uptake in the striatum and clinical extrapyramidal signs (EPSs) in patients with a diagnosis of probable DLB to clarify the extent to which the supporting role of I-FP-CIT is related to motor impairment. METHODS: Semiquantitative I-FP-CIT uptake was analyzed and correlated with Unified Parkinson Disease Rating Scale Part III scores in a sample of 22 patients with a diagnosis of probable DLB and a wide range of EPSs. RESULTS: A significant negative linear correlation between I-FP-CIT uptake and Unified Parkinson Disease Rating Scale Part III score was found both in the caudate and the putamen (r = -0.69 and -0.72, respectively, P < 0.001). Striatal uptake in patients with no or questionable EPS was comparable to that recorded in normal age-matched subjects (99% [22%] in the putamen) but significantly reduced in those with mild and severe EPS (43% [35%] and 30% [17%], respectively, P < 0.0001, but P = nonsignificant between mild and severe EPS). CONCLUSIONS: SPECT may be redundant when there are no doubts about the parkinsonism (ie, when it is absent or unequivocally present), but it may be helpful in identifying presynaptic nigrostriatal degeneration in patients with mild EPSs.


Subject(s)
Lewy Body Disease/diagnostic imaging , Radiopharmaceuticals , Tomography, Emission-Computed, Single-Photon , Tropanes , Aged , Female , Humans , Lewy Body Disease/pathology , Male
16.
Nanomedicine (Lond) ; 9(10): 1457-74, 2014 Jul.
Article in English | MEDLINE | ID: mdl-24823433

ABSTRACT

AIM: To study the specificity of cellular MRI based on superparamagnetic iron oxide particles (SPIOs), especially within the CNS. MATERIALS & METHODS: A microglial cell line was engineered for the expression of a suicide gene, the receptor of diphtheria toxin (DT), and two reporter genes, green fluorescent protein and luciferase, in order to induce, in a controlled manner, cell death and test it through bioluminescence. SPIO-labeled DT-sensitive and control DT-insensitive cells were transplanted into the brains of mice, which underwent serial MRI and bioluminescence studies before and up to 90 days after DT-induced cell death. RESULTS: No variations in SPIO signal voids were detected along longitudinal monitoring in brain hemispheres transplanted with DT-sensitive cells. Ex vivo analyses showed persistence of iron nanoparticle deposits at transplantation sites. CONCLUSION: Due to the long-term persistence of signal after transplanted cell death, caution is advised when SPIOs are employed for cell tracking.


Subject(s)
Brain/cytology , Cell Tracking/methods , Dextrans , Magnetic Resonance Imaging/methods , Magnetite Nanoparticles , Microglia/cytology , Microglia/transplantation , Animals , Apoptosis/physiology , Brain/surgery , Cell Line , Female , Longitudinal Studies , Mice , Mice, Nude
17.
Nucl Med Commun ; 35(4): 416-22, 2014 Apr.
Article in English | MEDLINE | ID: mdl-24457319

ABSTRACT

INTRODUCTION: Measurement of the glomerular filtration rate (GFR) is recognized worldwide as the most accurate way of assessing kidney function. The prevalence of impaired renal function increases with advancing age. In this study we compared the clinical formulae Cockcroft-Gault (CG), isotope dilution mass spectrometry-modification of diet in renal disease (IMDS-MDRD) and chronic kidney disease epidemiology collaboration (CKD-EPI) with (99m)Tc-diethylene triamine pentaacetic acid ((99m)Tc-DTPA) in elderly patients over and under the age of 70 years in an attempt to establish which formula produces the best measurement of renal function in this population. MATERIALS AND METHODS: Patients were randomly selected from two age groups [<70 years (n = 37) and ≥ 70 years (n = 39)]. Two plasma samples were collected at 60 and 180 min after injection of (99m)Tc-DTPA, and the GFR was calculated applying Charles D. Russell's two-sample method. RESULTS: In patients younger than 70 years, no statistically significant difference was found between GFR evaluated with (99m)Tc-DTPA and GFR obtained using the other methods.In patients aged at least 70 years, no statistically significant difference was found between GFR evaluated with (99m)Tc-DTPA and GFR evaluated using the CG real weight formula. Conversely, statistically significant differences were found between GFR evaluated with (99m)Tc-DTPA and GFR obtained using the CG normalized weight (P = 0.002), IMDS-MDRD (P = 0.024) and CKD-EPI (P = 0.028) formulae. DISCUSSION AND CONCLUSION: In patients older than 70 years, the use of the two 'classical' formulae (IMDS-MDRD and CKD-EPI) overestimated GFR in stage III CKD (GFR 30-59 ml/min) when compared with the gold standard (99m)Tc-DTPA method. Thus, in patients aged 70 years and above only the CG real weight formula provided unbiased results comparable to (99m)Tc-DTPA. In conclusion, in elderly patients, GFR measured using CKD-EPI and IMDS-MDRD serum creatinine-based formulae may be overestimated compared with that measured using (99m)Tc-DTPA GFR.


Subject(s)
Creatinine/blood , Kidney Function Tests/methods , Technetium Tc 99m Pentetate , Age Factors , Aged , Female , Glomerular Filtration Rate , Humans , Male
18.
Multidiscip Respir Med ; 8(1): 75, 2013 Dec 19.
Article in English | MEDLINE | ID: mdl-24354912

ABSTRACT

The diagnosis of pulmonary embolism (PE) is frequently considered in patients presenting to the emergency department or when hospitalized. Although early treatment is highly effective, PE is underdiagnosed and, therefore, the disease remains a major health problem. Since symptoms and signs are non specific and the consequences of anticoagulant treatment are considerable, objective tests to either establish or refute the diagnosis have become a standard of care. Diagnostic strategy should be based on clinical evaluation of the probability of PE. The accuracy of diagnostic tests for PE are high when the results are concordant with the clinical assessment. Additional testing is necessary when the test results are inconsistent with clinical probability. The present review article represents the consensus-based recommendations of the Interdisciplinary Association for Research in Lung Disease (AIMAR) multidisciplinary Task Force for diagnosis and treatment of PE. The aim of this review is to provide clinicians a practical diagnostic and therapeutic management approach using evidence from the literature.

19.
Arch Ital Biol ; 151(3): 114-25, 2013 Sep.
Article in English | MEDLINE | ID: mdl-24599629

ABSTRACT

We set out to assess the feasibility of exploiting expression of the mCherry gene, after lentiviral infection, in order visualise bone marrow-derived human mesenchymal stem cells (hMSCs) by optical imaging, and to provide proof of principle of this approach as a method for cell tracking and quantification in pre-clinical models. Commercial hMSCs were infected with a lentiviral vector carrying the mCherry gene under the control of the phosphoglycerate kinase promoter. After extensive in vitro culture, infected hMSCs were analysed for viability, morphology, differentiation capability, and maintenance of fluorescence. Thereafter, mCherry-positive cells were transplanted into unilaterally 6-hydroxy-dopamine lesioned rats (an experimental model of Parkinson's disease). Our analysis showed that hMSCs can be efficiently transduced with the lentiviral vector, retaining their biological features even in the long term. Intrastriatally transplanted mCherry-positive hMSCs can be detected ex vivo by a sensitive cooled CCD camera, both in the whole brain and in serial slices, and relatively quantified. Our protocol was found to be a reliable means of studying the viability of implanted hMSCs. mCherry labelling appears to be readily applicable in the post-transplantation tracking of stem cells and could favour the rapid development of new therapeutic targets for clinical treatments.


Subject(s)
Flow Cytometry , Mesenchymal Stem Cell Transplantation/methods , Neurodegenerative Diseases/surgery , Optogenetics , Adrenergic Agents/toxicity , Animals , Cells, Cultured , Disease Models, Animal , Humans , Lentivirus/genetics , Luminescent Proteins/genetics , Luminescent Proteins/metabolism , Male , Mesenchymal Stem Cells/physiology , Neurodegenerative Diseases/chemically induced , Oxidopamine/toxicity , Rats , Rats, Sprague-Dawley , Thy-1 Antigens/metabolism , Time Factors , Transfection , Red Fluorescent Protein
20.
Eur J Nucl Med Mol Imaging ; 39(11): 1720-9, 2012 Nov.
Article in English | MEDLINE | ID: mdl-22740098

ABSTRACT

PURPOSE: In nuclear medicine, radiopharmaceuticals are usually administered in unit doses partitioned from multi-dose vials. The partitioning typically takes place in a radiopharmacy, depending on local practice. Automatic, as opposed to manual, partitioning and administration should reduce radiation exposure of the personnel involved, improve the accuracy of the administration and mitigate contamination. This study set out to verify and validate the (18)F-fluorodeoxyglucose (FDG) administration procedure performed using Intego (MEDRAD, Inc., Warrendale, PA, USA), a combined dispenser and injector system. We considered maintenance of sterility and the system's potential to improve, with respect to the manual procedure, the accuracy of net administered (18)F-FDG radioactivity in patients and the radiation protection of operators. METHODS: A media-fill procedure was used to assess whether sterility is maintained during use of the Intego system. Simulating a typical working day's setup and use of the system, we investigated the accuracy of the net administered (18)F-FDG activity obtained with Intego versus the manual dose delivery system. We also measured personnel radiation exposure during use of Intego and during manual administration and recorded and compared environmental doses in the two conditions. RESULTS: The radiopharmaceutical remained sterile in all the tests performed. The accuracy of the net (18)F-FDG activity delivered to the patients was found to be within 3 % points, as required by European Association of Nuclear Medicine (EANM) guidelines on (18)F-FDG imaging procedures. With Intego, the residual radioactivity in the tubing was 0.20 MBq, corresponding to approximately 0.07 % of the mean activity delivered. With manual injection, the residual radioactivity in the syringe averaged 7.37 MBq, corresponding to a mean error of 2.9 % in the delivered dose. During the injection step of the positron emission tomography (PET) procedure, whole-body and extremity radiation exposures were significantly reduced with Intego by 38 and by 94 %, respectively, compared to the levels associated with manual administration (p < 0.05). CONCLUSION: Integoaccurately partitions and administers sterile doses of (18)F-FDG from multi-dose vials. Compared with standard manual (18)F-FDG administration, the new procedure with an automatic dispensing and injection system greatly reduces the extremity dose to the operator involved in the administration of the radiopharmaceutical.


Subject(s)
Fluorodeoxyglucose F18/administration & dosage , Infusions, Intravenous/methods , Injections/methods , Radiopharmaceuticals/administration & dosage , Humans , Infusion Pumps , Infusions, Intravenous/instrumentation , Injections/instrumentation , Multimodal Imaging/instrumentation , Multimodal Imaging/methods , Positron-Emission Tomography , Tomography, X-Ray Computed
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