In vivo imaging and characterization of [(18)F]DPA-714, a potential new TSPO ligand, in mouse brain and peripheral tissues using small-animal PET

INTRODUCTION

The translocator protein 18 kDa (TSPO), a biochemical marker of neuroinflammation, is highly expressed in the brain activated microglia and it is also expressed by peripheral inflammatory cells and normal peripheral tissues. Thus, development of radioligands for the TSPO may contribute to further understanding the in vivo TSPO function in central and peripheral inflammatory processes and other pathologies. Here, we report the biodistribution, the specific binding and the radiometabolites of [(18)F]DPA-714, a promising fluorinated PET radiotracer, in normal mice using a microPET/CT scanner.

METHODS

The in vivo biodistribution and kinetics of [(18)F]DPA-714 were measured in mice brain and peripheral tissues. Specific binding to TSPO sites was assessed using pharmacological competitive studies by means of saturation experiments performed by i.v. injection of 1mg/kg of unlabeled DPA-714 or 3mg/kg of unlabeled PK11195. A region of interest analysis was performed to generate time-activity curves in the brain, heart, lung, kidney, spleen and liver. Metabolites assay was performed in the plasma and peripheral organs by radio-HPLC.

RESULTS

[(18)F]DPA-714 reached high concentration in lung, heart, kidney and spleen, tissues well known to be rich in TSPO sites. [(18)F]DPA-714 kinetics were faster in the lung and slower in the kidney. Pre-injection of unlabeled DPA-714 or PK11195 inhibited about 80% of [(18)F]DPA-714 uptake in the lung and heart (p<0.0005). The percentage of inhibition in the kidney was lower and achieved at later times only with DPA-714 (p<0.05) but not with PK11195. Sixty minutes after radiotracer injection only unmetabolized radioligand was found in the brain, lung, heart and spleen.

CONCLUSION

These results suggest that [(18)F]DPA-714 is a suitable PET ligand for imaging in mice brain and peripheral tissues since it binds with high specificity TSPO binding sites and it is almost unchanged at 60 minutes after radiotracer injection in the brain and TSPO-rich regions.

Evaluation of the effectiveness of a polyhexanide and propyl betaine-based gel in the treatment of chronic wounds

AIM

The objective of this multicenter observational clinical study was to evaluate the therapeutic effects of a polyhexanide and propyl betaine-based gel in the treatment of patients of every age, affected by chronic skin wounds.

METHODS

One hundred twenty-four patients (60% females, from 4-day-old to 91-year-old, mean age 59) were treated with polyhexanide/propyl betaine (Prontosan® Wound Gel, B. Braun) applied directly on the surface of the wound and in the possible undermining, in combination with a secondary dressing. At the baseline visit and at subsequent checks were evaluated the wound diameter and characteristics (the wound bed and the surrounding skin and edges appearance, level and type of exudate) and local pain at dressing change.

RESULTS

The assessment and analysis between the initial visit and the final one showed the following results: the wound size and pain characteristics have decreased substantially and significantly (P<0.001) both in the size of the wounds (length: -17.5 ± 21.4 cm, width: -15.5 ± 21.1 cm; area: -8.3 ± 16.7 cm²) and in the intensity of pain perceived by the patient (Visual Analogue Scale [VAS]: -4.67 ± 2.7; Face, Legs, Activity, Cry, Consolability [FLACC] Scale <1 ± 4); for patients younger than 3 years, the scale used was FLACC. Wound bed: it was found a significant increase in the percentage of improvement in patients; 90% of them showed a reduction in the wound size, while 80% of them showed a relative reduction in pain compared with that observed during the baseline visit, with the wound bed cleansed, granulating or re-epithelializing. Just as significant was the decrease in percentage of subjects with wounds with fibrinous and partially necrotic bed, and/or with biofilm. Edges of the wound and periwound skin: the percentage of patients who have shown during the treatment an improvement in the clinical condition both of the wound edges and the surrounding skin has significantly increased, with a number of cases (75%) who have reached complete skin integrity. In a smaller percentage, already at the initial visit, the wound edges (28%) or the peristomal skin (18%) have been found undamaged. Exudate: there was a reduction in the level of exudate, with 74% of patients who showed no exudate at the final visit, compared with 15% of patients with non-exudative wounds at baseline.

CONCLUSION

The treatment of chronic skin wounds through the use of a polyhexanide/propyl betaine-based gel, in combination with a secondary dressing, showed significant improvements, such as a 30% reduction of pain at dressing change, the reduction in the size and characteristics of the wounds and a reduction in the levels of exudate. All these factors have contributed to a reduction in the number of dressings, thus reducing the overall cost of treatment.

Evidence and role of autoantibodies in chronic rhinosinusitis with nasal polyps

In this study, we review our current knowledge of the autoimmune etiopathogenesis of chronic rhinosinusitis with nasal polyps including bacterial infections, viral infections and immunomediated mechanisms and to discuss pathogenesis with relevance for pharmacotherapy. Relevant publications on the etiopathogenesis and treatment of chronic rhinosinusitis with nasal polyps (CRSwNP) from 1977 to 2013 were analyzed. The characteristic signs and symptoms include appearance of relapsing nasal polyps, with typical symptoms such as nasal obstruction, nasal discharge and, usually, loss of the sense of smell. The etiology and pathogenesis remain unknown. Proposed theories of causation include bacterial or viral infections and immunomediated mechanisms. The autoimmune aetiology of unknown origin or failure to respond to classic pharmacological treatments with nasal and oral steroids is now suspected. At present, the nature of the antigen trigger, the exact role played by B/T cells and anti-dsDNA autoantibodies in the pathogenesis of nasal polyposis remains unclear. Corticosteroids and surgery are the first line of treatment in CRSwNP. In the case of corticosteroid treatment failure, other drugs can be used such as rituximab, belimumab or omalizumab which have demonstrated clinical efficacy in the treatment of nasal polyposis with comorbid asthma. Immunosuppressive drugs such as methotrexate, and cyclophosphamide have also been used with varying degrees of success.

Genetic deletion in uncoupling protein 3 augments 18F-fluorodeoxyglucose cardiac uptake in the ischemic heart

Background

We investigated the effects of uncoupling protein 3 (UCP3) genetic deletion on ¹⁸F-fluorodeoxyglucose (FDG) cardiac uptake by positron emission tomography (PET)/computed tomography (CT) dedicated animal system after permanent coronary artery ligation.

Methods

Cardiac ¹⁸F-FDG PET/CT was performed in UCP3 knockout (UCP3^−/−) and wild-type (WT) mice one week after induction of myocardial infarction or sham procedure.

Results

In sham-operated mice no difference in left ventricular (LV) volume was detectable between WT and UCP3^−/−. After myocardial infarction, LV volume was higher in both WT and UCP3^−/− compared to sham animals, with a significant interaction (p < 0.05) between genotype and myocardial infarction. In sham-operated animals no difference in FDG standardized uptake value (SUV) was detectable between WT (1.8 ± 0.6) and UCP3^−/− (1.8 ± 0.6). After myocardial infarction SUV was significantly higher in remote areas than in infarcted territories in both UCP3−/− and WT mice (both p < 0.01). Moreover, in remote areas, SUV was significantly higher (p < 0.001) in UCP3−/− as compared to WT, while in the infarcted territory SUV was comparable (p = 0.29). A significant relationship (r = 0.68, p < 0.001) between LV volume and SUV was found.

Conclusions

In a mice model of permanent coronary occlusion, UCP3 deficiency results in a metabolic shift that favored glycolytic metabolism and increased FDG uptake in remote areas.

Monitoring reversal of MET-mediated resistance to EGFR tyrosine kinase inhibitors in non-small cell lung cancer using 3'-deoxy-3'-[18F]-fluorothymidine positron emission tomography

PURPOSE

MET amplification is one of the mechanisms underlying acquired resistance to EGFR tyrosine kinase inhibitors (TKI) in non-small cell lung cancer (NSCLC). Here, we tested whether 3'-deoxy-3'-[(18)F]-fluorothymidine ([(18)F]FLT) positron emission tomography/computerized tomography (PET/CT) can detect MET-mediated resistance to EGFR TKIs and monitor the effects of MET inhibitors in NSCLC.

EXPERIMENTAL DESIGN

H1993 and H820 NSCLC cells with high and low levels of MET amplification, respectively, and HCC827-expressing MET, but without gene amplification, were tested for the effects of MET inhibitors on the EGFR pathway and proliferation both in vitro and in vivo. Nude mice bearing NSCLCs with and without MET amplification were subjected to [(18)F]FLT PET/CT before and after treatment with crizotinib or erlotinib (50 mg/kg and 100 mg/kg p.o. for 3 days).

RESULTS

H1993 cells showed high responsiveness to MET inhibitors and were resistant to erlotinib. Conversely, HCC827 cells showed high sensitivity to erlotinib and were resistant to MET inhibitors. Accordingly, H1993 tumors bearing MET amplification showed a mean reduction in [(18)F]FLT uptake of 28% and 41% after low- and high-dose treatment with crizotinib for 3 days, whereas no posttherapy changes of [(18)F]FLT uptake were observed in HCC827 tumors lacking MET amplification. Furthermore, a persistently high [(18)F]FLT uptake was observed in H1993 tumors after treatment with erlotinib, whereas HCC827 tumors showed up to 39% reduction of [(18)F]FLT uptake following erlotinib treatment. Imaging findings were confirmed by Ki67 immunostaining of tumor sections.

CONCLUSIONS

[(18)F]FLT PET/CT can detect MET-mediated resistance to EGFR TKIs and its reversal by MET inhibitors in NSCLC.

Is vestibular neuritis an immune related vestibular neuropathy inducing vertigo?

OBJECTIVES

To review the current knowledge of the aetiology of vestibular neuritis including viral infections, vascular occlusion, and immunomediated mechanisms and to discuss the pathogenesis with relevance to pharmacotherapy.

SYSTEMATIC REVIEW METHODOLOGY

Relevant publications on the aetiology and treatment of vestibular neuritis from 1909 to 2013 were analysed.

RESULTS AND CONCLUSIONS

Vestibular neuritis is the second most common cause of peripheral vestibular vertigo and is due to a sudden unilateral loss of vestibular function. Vestibular neuronitis is a disorder thought to represent the vestibular-nerve equivalent of sudden sensorineural hearing loss. Histopathological studies of patients who died from unrelated clinical problems have demonstrated degeneration of the superior vestibular nerve. The characteristic signs and symptoms include sudden and prolonged vertigo, the absence of auditory symptoms, and the absence of other neurological symptoms. The aetiology and pathogenesis of the condition remain unknown. Proposed theories of causation include viral infections, vascular occlusion, and immunomediated mechanisms. The management of vestibular neuritis involves symptomatic treatment with antivertiginous drugs, causal treatment with corticosteroids, and physical therapy. Antiviral agents did not improve the outcomes.

Microbubble-assisted p53, RB, and p130 gene transfer in combination with radiation therapy in prostate cancer

Combining radiation therapy and direct intratumoral (IT) injection of adenoviral vectors has been explored as a means to enhance the therapeutic potential of gene transfer. A major challenge for gene transfer is systemic delivery of nucleic acids directly into an affected tissue. Ultrasound (US) contrast agents (microbubbles) are viable candidates to enhance targeted delivery of systemically administered genes. Here we show that p53, pRB, and p130 gene transfer mediated by US cavitation of microbubbles at the tumor site resulted in targeted gene transduction and increased reduction in tumor growth compared to DU-145 prostate cancer cell xenografts treated intratumorally with adenovirus (Ad) or radiation alone. Microbubble-assisted/US-mediated Ad.p53 and Ad.RB treated tumors showed significant reduction in tumor volume compared to Ad.p130 treated tumors (p<0.05). Additionally, US mediated microbubble delivery of p53 and RB combined with external beam radiation resulted in the most profound tumor reduction in DU-145 xenografted nude mice (p<0.05) compared to radiation alone. These findings highlight the potential therapeutic applications of this novel image-guided gene transfer technology in combination with external beam radiation for prostate cancer patients with therapy resistant disease.

Cognitive vulnerability to depressive symptoms in children: the protective role of self-efficacy beliefs in a multi-wave longitudinal study

The current multi-wave longitudinal study on childhood examined the role that social and academic self-efficacy beliefs and cognitive vulnerabilities play in predicting depressive symptoms in response to elevations in idiographic stressors. Children (N = 554; males: 51.4 %) attending second and third grade completed measures of depressive symptoms, negative cognitive styles, negative life events, and academic and social self-efficacy beliefs at four time-points over 6 months. Results showed that high levels of academic and social self-efficacy beliefs predicted lower levels of depressive symptoms, whereas negative cognitive styles about consequences predicted higher depression. Furthermore, children reporting higher social self-efficacy beliefs showed a smaller elevation in levels of depressive symptoms when reporting an increases in stress than children with lower social self-efficacy beliefs. Findings point to the role of multiple factors in predicting children's depression in the long term and commend the promotion of self-efficacy beliefs and the modification of cognitive dysfunctional styles as relevant protective factors.

Effects of some anesthetic agents on skin microcirculation evaluated by laser Doppler perfusion imaging in mice

Background

Anesthetic agents alter microcirculation, influencing tissue oxygenation and delivery of vital substrates. Laser Doppler perfusion imaging is a widespread technique in the field of microvascular research that can evaluate noninvasively and in real time the effects of environmental conditions, physical manipulations, diseases and treatments on peripheral perfusion. This study aims to evaluate laser Doppler perfusion imaging as a means to detect changes in skin microcirculation induced by some popular anesthetic agents in a murine model. Twenty-four age- and gender-matched healthy CD1 mice were examined by laser Doppler perfusion imaging. The skin microcirculatory response was measured at the level of plantar surfaces during isoflurane anesthesia with or without subsequent dexmedetomidine or acepromazine. At the end of the procedure, dexmedetomidine was reversed by atipamezole administration.

Results

In all mice, skin blood flow under isoflurane anesthesia did not show significant differences over time (P = 0.1). The serial perfusion pattern and values following acepromazine or dexmedetomidine administration differed significantly (P < 0.05).

Conclusions

We standardized a reliable laser Doppler perfusion imaging protocol to non-invasively assess changes in skin microcirculation induced by anesthesia in mice, considering the advantages and drawbacks of this technique and its translational value.

Dysphagia in amyotrophic lateral sclerosis: prevalence and clinical findings

OBJECTIVES

To characterize swallowing deficits in amyotrophic lateral sclerosis (ALS); investigate the delay in dysphagia onset; estimate correlations between dysphagia severity and patients' functional status; identify the symptom(s) most likely to predict dysphagia.

MATERIALS AND METHODS

A group of 49 consecutive patients with ALS, 14 with bulbar onset and 35 with spinal onset, underwent swallowing evaluation including bedside and fiberoptic endoscopic examination to detect dysphagia.

RESULTS

Patients with dysphagia were more likely than those without to have bulbar onset ALS (P = 0.02); more severely impaired chewing (P = 0.01); and tongue muscle deficits (P = 0.001). The only variable measured at first examination significantly associated with dysphagia was a more than mild tongue muscle deficit. The only variable useful in predicting dysphagia was a chewing deficit. In 10 of the 49 patients studied, swallowing evaluation disclosed an impaired cough reflex.

CONCLUSIONS

Dysphagia in patients with ALS correlates significantly with bulbar onset and with oral swallowing impairment. Fiberoptic swallowing evaluation is a useful tool for detecting swallowing deficits and laryngeal sensitivity in patients with ALS. An impaired cough reflex is an unexpected finding in many patients with ALS.

Assessment of dual-energy x-ray absorptiometry for use in evaluating the effects of dietary and environmental management on Hermann's tortoises (Testudo hermanni)

OBJECTIVE

To assess dual-energy x-ray absorptiometry (DXA) for evaluating effects of diet and environment on bone mineral density in Hermann's tortoises (Testudo hermanni).

ANIMALS

26 Hermann's tortoises within 1 month after hatching.

PROCEDURES

Group 1 was housed in an artificial setting and fed naturally growing vegetation. Group 2 was housed in an artificial setting and fed vegetables grown for human consumption. Group 3 was maintained in an outside enclosure and fed naturally growing vegetation. After 10 months, pyramidal growth, body weight, and adverse conditions were assessed. Bone mineral density (BMD) of the axial and appendicular skeleton, shell, vertebral column, and pelvis was measured via DXA.

RESULTS

Group 2 had the highest mean ± SD body weight (65.42 ± 30.85 g), followed by group 1 (51.08 ± 22.92 g) and group 3 (35.74 ± 7.13 g). Mean BMD of the shell varied significantly among groups (group 1, 0.05 ± 0.03 g/cm(2)•m; group 2, 0.09 ± 0.15 g/cm(2)•m; and group 3, undetectable). The BMD of the axial and appendicular skeleton, vertebral column, and pelvis did not differ significantly among groups. Pyramidal growth was highest in group 1 and not evident in group 3.

CONCLUSIONS AND CLINICAL RELEVANCE

Tortoises raised in artificial conditions did not have deficits in BMD, compared with results for outdoor-housed hibernating tortoises. Supplemental calcium was apparently not necessary when an adequate photothermal habitat and plant-based diet were provided. Higher BMD of captive-raised tortoises was morphologically associated with a higher incidence of pyramidal growth in captive-raised groups.

High frequency ultrasound for in vivo pregnancy diagnosis and staging of placental and fetal development in mice

Background

Ultrasound is a valuable non-invasive tool used in obstetrics and gynecology to monitor the growth and well being of the human fetus. The laboratory mouse has recently emerged as an appropriate model for fetal and perinatal studies because morphogenetic processes in mice exhibit adequate homology to those in humans, and genetic manipulations are relatively simple to perform in mice. High-frequency ultrasound (HFUS) has recently become available for small animal preclinical imaging and can be used to study pregnancy and development in the mouse. The objective of the current study was to assess the main applications of HFUS in the evaluation of fetal growth and placental function and to better understand human congenital diseases.

Methodology/Principal Findings

On each gestational day, at least 5 dams were monitored with HFUS; a total of ∼200 embryos were examined. Because it is not possible to measure each variable for the entire duration of the pregnancy, the parameters were divided into three groups as a function of the time at which they were measured. Univariate analysis of the relationship between each measurement and the embryonic day was performed using Spearman’s rank correlation (Rs). Continuous linear regression was adopted for multivariate analysis of significant parameters. All statistical tests were two-sided, and a p value of 0.05 was considered statistically significant.

Conclusions/Significance

The study describes the main applications of HFUS to assess changes in phenotypic parameters in the developing CD1 mouse embryo and fetus during pregnancy and to evaluating physiological fetal and placental growth and the development of principal organs such as the heart, kidney, liver, brain and eyes in the embryonic mouse. A database of normal structural and functional parameters of mouse development will provide a useful tool for the better understanding of morphogenetic and cardiovascular anomalies in transgenic and mutant mouse models.

Imaging of thyroid tumor angiogenesis with microbubbles targeted to vascular endothelial growth factor receptor type 2 in mice

BACKGROUND

To evaluate whether Contrast Enhanced Ultrasund (CEUS) with microbubbles (MBs) targeted to VEGFR-2 is able to characterize in vivo the VEGFR-2 expression in the tumor vasculature of a mouse model of thyroid cancer (Tg-TRK-T1).

METHODS

Animal protocol was approved by Institutional committee on Laboratory Animal Care. Contrast-enhanced ultrasound imaging with MBs targeted with an anti-VEGFR-2 monoclonal antibody (UCAVEGFR-2) and isotype control antibody (UCAIgG) was performed in 7 mice with thyroid carcinoma, 5 mice with hyperplasia or benign thyroid nodules and 4 mice with normal thyroid. After ultrasonography, the tumor samples were harvested for histological examination and VEGFR-2 expression was tested by immunohistochemistry. Data were reported as median and range. Paired non parametric Wilcoxon's test and ANOVA of Kruskal-Wallis were used. The correlation between the contrast signal and the VEGFR-2 expression was assessed by the Spearman coefficient.

RESULTS

The Video intensity difference (VID) caused by backscatter of the retained UCAVEGFR-2 was significantly higher in mice harboring thyroid tumors compared to mice with normal thyroids (P < 0.01) and to mice harboring benign nodules (P < 0.01). No statistically significant differences of VID were observed in the group of mice carrying benign nodules compared to mice with normal thyroids. Moreover in thyroid tumors VID of retained VEGFR-2-targeted UCA was significantly higher than that of control UCAIgG (P <0.05). Results of immunohistochemical analysis confirmed VEGFR-2 overexpression. The magnitude of the molecular ultrasonographic signal from a VEGFR-2-targeted UCA retained by tissue correlates with VEGFR-2 expression determined by immunohistochemistry (rho 0.793, P=0.0003).

CONCLUSIONS

We demonstrated that CEUS with UCAVEGFR-2 might be used for in vivo non invasive detection and quantification of VEGFR-2 expression in thyroid cancer in mice, and to differentiate benign from malignant thyroid nodules.

Imaging of thyroid tumor angiogenesis with microbubbles targeted to vascular endothelial growth factor receptor type 2 in mice

Background

To evaluate whether Contrast Enhanced Ultrasund (CEUS) with microbubbles (MBs) targeted to VEGFR-2 is able to characterize in vivo the VEGFR-2 expression in the tumor vasculature of a mouse model of thyroid cancer (Tg-TRK-T1).

Methods

Animal protocol was approved by Institutional committee on Laboratory Animal Care. Contrast-enhanced ultrasound imaging with MBs targeted with an anti-VEGFR-2 monoclonal antibody (UCA_VEGFR-2) and isotype control antibody (UCA_IgG) was performed in 7 mice with thyroid carcinoma, 5 mice with hyperplasia or benign thyroid nodules and 4 mice with normal thyroid. After ultrasonography, the tumor samples were harvested for histological examination and VEGFR-2 expression was tested by immunohistochemistry. Data were reported as median and range. Paired non parametric Wilcoxon’s test and ANOVA of Kruskal-Wallis were used. The correlation between the contrast signal and the VEGFR-2 expression was assessed by the Spearman coefficient.

Results

The Video intensity difference (VI_D) caused by backscatter of the retained UCA_VEGFR-2 was significantly higher in mice harboring thyroid tumors compared to mice with normal thyroids (P < 0.01) and to mice harboring benign nodules (P < 0.01). No statistically significant differences of VI_D were observed in the group of mice carrying benign nodules compared to mice with normal thyroids. Moreover in thyroid tumors VI_D of retained VEGFR-2-targeted UCA was significantly higher than that of control UCA_IgG (P <0.05). Results of immunohistochemical analysis confirmed VEGFR-2 overexpression. The magnitude of the molecular ultrasonographic signal from a VEGFR-2-targeted UCA retained by tissue correlates with VEGFR-2 expression determined by immunohistochemistry (rho 0.793, P=0.0003).

Conclusions

We demonstrated that CEUS with UCA_VEGFR-2 might be used for in vivo non invasive detection and quantification of VEGFR-2 expression in thyroid cancer in mice, and to differentiate benign from malignant thyroid nodules.

PCAF ubiquitin ligase activity inhibits Hedgehog/Gli1 signaling in p53-dependent response to genotoxic stress

The Hedgehog (Hh) signaling regulates tissue development, and its aberrant activation is a leading cause of malignancies, including medulloblastoma (Mb). Hh-dependent tumorigenesis often occurs in synergy with other mechanisms, such as loss of p53, the master regulator of the DNA damage response. To date, little is known about mechanisms connecting DNA-damaging events to morphogen-dependent processes. Here, we show that genotoxic stress triggers a cascade of signals, culminating with inhibition of the activity of Gli1, the final transcriptional effector of Hh signaling. This inhibition is dependent on the p53-mediated elevation of the acetyltransferase p300/CBP-associated factor (PCAF). Notably, we identify PCAF as a novel E3 ubiquitin ligase of Gli1. Indeed PCAF, but not a mutant with a deletion of its ubiquitination domain, represses Hh signaling in response to DNA damage by promoting Gli1 ubiquitination and its proteasome-dependent degradation. Restoring Gli1 levels rescues the growth arrest and apoptosis effect triggered by genotoxic drugs. Consistently, DNA-damaging agents fail to inhibit Gli1 activity in the absence of either p53 or PCAF. Finally, Mb samples from p53-null mice display low levels of PCAF and upregulation of Gli1 in vivo, suggesting PCAF as potential therapeutic target in Hh-dependent tumors. Together, our data define a mechanism of inactivation of a morphogenic signaling in response to genotoxic stress and unveil a p53/PCAF/Gli1 circuitry centered on PCAF that limits Gli1-enhanced mitogenic and prosurvival response.

Mice anesthesia, analgesia, and care, Part II: anesthetic considerations in preclinical imaging studies

Animal experiments are necessary for a better understanding of diseases and for developing new therapeutic strategies. The mouse (Mus musculus) is currently the most popular laboratory animal in biomedical research. Mice imaging procedures are increasingly used in preclinical research because they allow in vivo monitoring and they are readily available for longitudinal and noninvasive studies as well as investigations into the evolution of diseases and the effects of new therapies. New imaging techniques and sophisticated laboratory animal imaging tools are currently producing a large body of evidence about the possible interference of anesthesia with different imaging methods that have the potential to compromise the results of in vivo studies. The purpose of this article is to review the existing literature on molecular imaging studies in mice, to describe the effects of different anesthetic protocols on their outcome, and to report our own experience with such studies.

Mice anesthesia, analgesia, and care, Part I: anesthetic considerations in preclinical research

Animal experiments are necessary for a better understanding of diseases and for developing new therapeutic strategies. The mouse (Mus musculus) is currently the most popular laboratory animal in biomedical research. Experimental procedures on animals often require anesthesia and/or analgesia to obtain adequate immobilization and to reduce stress or pain. Mice anesthesia is challenging for several reasons including the animals' size, metabolic rate, and the high risk of hypothermia and hypoglycemia. Moreover, anesthetic agents influence physiological parameters, further interfering with experimental results. Small animal imaging procedures are increasingly used in biomedical research both because the animals allow in vivo monitoring and because they are readily available for longitudinal and noninvasive studies as well as investigations into the evolution of diseases and the effects of new therapies. Anesthesia must adapt to the imaging technique, the procedure length, and the aim of the study. The purpose of this article is to review the existing literature on anesthetic protocols adopted in mice for molecular imaging studies and to report our experience.

Rotational Molding of Polyamide-6 Nanocomposites with Improved Flame Retardancy

The aim of this work was to develop polyamide-6/ organic-modified montmorillonite (omMMT) nanocomposites for the production of hollow parts by rotational molding. Particular emphasis was placed on the mechanical and flame retardancy properties needed for the fabrication of vessels for flammable liquids. The morphology of the melt compounded nanocomposites, produced by melt compounding, was investigated by X-ray diffraction measurements (WAXD), and Transmission Electron Microscopy (TEM) showed an exfoliated structure. Rheological measurements were used in order to verify whether the viscosity of materials was adequate for rotational molding. While thermomechanical analysis has revealed that neat PA6 and its nanocomposites were not suitable for rotational molding, due to the very low thermal stability of the polymer, the addition of a thermal stabilizer, shifted the onset of degradation to higher temperatures, thus widening the processing window of both PA6 and PA6 nanocomposites. Large-scale vessel prototypes were obtained by rotational molding of thermo-stabilized PA6 and its nanocomposites, and samples extracted from the rotomolded parts were characterized with respect to physical and mechanical properties. It was found that the PA6 nanocomposites exhibited significant improvements at cone calorimeter tests in comparison with neat PA6.

Vogt-Koyanagi-Harada syndrome

OBJECTIVES

The objectives of this study are to review our current knowledge of the aetiopathogenesis of Vogt-Koyanagi-Harada syndrome, including viral infection, genetic factors and immunomediated mechanisms, and to discuss pathogenesis and its relevance to pharmacotherapy.

SYSTEMATIC REVIEW METHODOLOGY

Relevant publications from 1965 to 2012 on the aetiopathogenesis and pharmacotherapy of VKHS were analysed.

RESULTS AND CONCLUSION

Vogt-Koyanagi-Harada syndrome (VKHS) is a rare multisystemic autoimmune disease that affects tissues containing melanin, including the eye, inner ear, meninges, and skin. The disease is characterised by bilateral uveitis associated with a varying constellation of auditory, neurological and cutaneous manifestations. The disease occurs more frequently among people with darker skin pigmentation. Asians, Native Americans, and Hispanics are most frequently affected. It predominates in patients aged between 20 and 50years, and females are affected more frequently, with a female:male ratio of 2:1. The classic clinical course is characterised by bilateral panuveitis, hypoacusis, and meningitis, in addition to cutaneous involvement with poliosis, vitiligo, and alopecia. Although the exact cause of VKH disease remains unknown, it is thought to be a T-cell-mediated autoimmune process directed against melanocytes. VKHS classically begins with vague systemic symptoms suggestive of a viral infection, although a clear association between a specific viral agent and the disease has not been established. Genetic factors may play an important role in the loss of self-tolerance in VKHS. The HLA-DRB1*0405 allele is the main susceptibility allele for VKHS. Early and aggressive systemic corticosteroids are still the primary initial therapy for VKHS. Ocular complications may require an intravitreous injection of corticosteroids. Despite proper treatment with steroids, a number of patients experience recurrent attacks or steroid-associated complications. Thus, non steroid immunomodulatory therapy (IMT) has become necessary for the treatment of VKHS.

A Psychometric Evaluation of the Group Environment Questionnaire in a Sample of Professional Basketball and Soccer Players

Psychometric properties of the Group Environment Questionnaire were investigated in a large sample of soccer ( n = 222) and professional basketball players ( n = 375). Confirmatory factor analysis was performed both on the total sample and on the two subsamples through a multi-group approach; associations between cohesion and the duration of belonging to the team were also explored. Results confirmed the four-factor structure proposed by Carron's original model even though some items with low loadings were eliminated. No significant associations were found between team cohesion and the duration of belonging to the team.

Repeatability, reproducibility and standardisation of a laser Doppler imaging technique for the evaluation of normal mouse hindlimb perfusion

BACKGROUND

Preclinical perfusion studies are useful for the improvement of diagnosis and therapy in dermatologic, cardiovascular and rheumatic human diseases. The Laser Doppler Perfusion Imaging (LDPI) technique has been used to evaluate superficial alterations of the skin microcirculation in surgically induced murine hindlimb ischemia. We assessed the reproducibility and the accuracy of LDPI acquisitions and identified several critical factors that could affect LDPI measurements in mice.

METHODS

Twenty mice were analysed. Statistical standardisation and a repeatability and reproducibility analysis were performed on mouse perfusion signals with respect to differences in body temperature, the presence or absence of hair, the type of anaesthesia used for LDPI measurements and the position of the mouse body.

RESULTS

We found excellent correlations among measurements made by the same operator (i.e., repeatability) under the same experimental conditions and by two different operators (i.e., reproducibility). A Bland-Altman analysis showed the absence of bias in repeatability (p = 0.29) or reproducibility (p = 0.89). The limits of agreement for repeatability were -0.357 and -0.033, and for reproducibility, they were -0.270 and 0.238. Significant differences in perfusion values were observed in different experimental groups.

CONCLUSIONS

Different experimental conditions must be considered as a starting point for the evaluation of new drugs and strategic therapies.

Inhomogeneous kinetic effects related to intermittent magnetic discontinuities

A connection between kinetic processes and two-dimensional intermittent plasma turbulence is observed using direct numerical simulations of a hybrid Vlasov-Maxwell model, in which the Vlasov equation is solved for protons, while the electrons are described as a massless fluid. During the development of turbulence, the proton distribution functions depart from the typical configuration of local thermodynamic equilibrium, displaying statistically significant non-Maxwellian features. In particular, temperature anisotropy and distortions are concentrated near coherent structures, generated as the result of the turbulent cascade, such as current sheets, which are nonuniformly distributed in space. Here, the partial variance of increments (PVI) method has been employed to identify high magnetic stress regions within a two-dimensional turbulent pattern. A quantitative association between non-Maxwellian features and coherent structures is established.

Canine lipomas treated with steroid injections: clinical findings

Lipomas are common benign tumours of fat cells. In most cases, surgical excision is curative and simple to perform; however, such a procedure requires general anaesthesia and may be associated with delayed wound healing, seroma formation and nerve injury in deep and intramuscular tumours. The objective of this study was to evaluate treatment of subcutaneous, subfascial or intermuscular lipomas using intralesional steroid injections in dogs. Fifteen dogs presenting with lipomas were selected for treatment with ultrasound-guided intralesional injection of triamcinolone acetonide at a dose of 40 mg/mL. Nine subcutaneous and subfascial tumours showed a complete regression. The other lipomas decreased in diameter, achieving, in some cases, remission of discomfort and regression of lameness. Steroid injection was a relatively safe and effective treatment for lipomas in dogs; only six dogs experienced polyuria/polydipsia for about 2 weeks post-treatment.

Sphingosine kinase 1 overexpression contributes to cetuximab resistance in human colorectal cancer models

PURPOSE

Although the anti-EGF receptor (EGFR) monoclonal antibody cetuximab is an effective strategy in colorectal cancer therapy, its clinical use is limited by intrinsic or acquired resistance. Alterations in the "sphingolipid rheostat"-the balance between the proapoptotic molecule ceramide and the mitogenic factor sphingosine-1-phosphate (S1P)-due to sphingosine kinase 1 (SphK1) overactivation have been involved in resistance to anticancer-targeted agents. Moreover, cross-talks between SphK1 and EGFR-dependent signaling pathways have been described.

EXPERIMENTAL DESIGN

We investigated SphK1 contribution to cetuximab resistance in colorectal cancer, in preclinical in vitro/in vivo models, and in tumor specimens from patients.

RESULTS

SphK1 was found overexpressed and overactivated in colorectal cancer cells with intrinsic or acquired resistance to cetuximab. SphK1 contribution to resistance was supported by the demonstration that SphK1 inhibition by N,N-dimethyl-sphingosine or silencing via siRNA in resistant cells restores sensitivity to cetuximab, whereas exogenous SphK1 overexpression in sensitive cells confers resistance to these agents. Moreover, treatment of resistant cells with fingolimod (FTY720), a S1P receptor (S1PR) antagonist, resulted in resensitization to cetuximab both in vitro and in vivo, with inhibition of tumor growth, interference with signal transduction, induction of cancer cells apoptosis, and prolongation of mice survival. Finally, a correlation between SphK1 expression and cetuximab response was found in colorectal cancer patients.

High-resolution positron emission tomography/computed tomography imaging of the mouse heart

Different animal models have been used to reproduce coronary heart disease, but in recent years mice have become the animals of choice, because of their short life cycle and the possibility of genetic manipulation. Various techniques are currently used for cardiovascular imaging in mice, including high-resolution ultrasound, X-ray computed tomography (CT), magnetic resonance imaging and nuclear medicine procedures. In particular, molecular imaging with cardiac positron emission tomography (PET) allows non-invasive evaluation of changes in myocardial perfusion, metabolism, apoptosis, inflammation and gene expression or measurement of changes in left ventricular functional parameters. With technological advances, dedicated small laboratory PET/CT imaging has emerged in cardiovascular research, providing in vivo a non-invasive, serial and quantitative assessment of left ventricular function, myocardial perfusion and metabolism at a molecular level. This non-invasive methodology might be useful in longitudinal studies to monitor cardiac biochemical parameters and might facilitate studies to assess the effect of different interventions after acute myocardial ischaemia.

Magnetic moment nonconservation in magnetohydrodynamic turbulence models

The fundamental assumptions of the adiabatic theory do not apply in the presence of sharp field gradients or in the presence of well-developed magnetohydrodynamic turbulence. For this reason, in such conditions the magnetic moment μ is no longer expected to be constant. This can influence particle acceleration and have considerable implications in many astrophysical problems. Starting with the resonant interaction between ions and a single parallel propagating electromagnetic wave, we derive expressions for the magnetic moment trapping width Δμ (defined as the half peak-to-peak difference in the particle magnetic moments) and the bounce frequency ω(b). We perform test-particle simulations to investigate magnetic moment behavior when resonance overlapping occurs and during the interaction of a ring-beam particle distribution with a broadband slab spectrum. We find that the changes of magnetic moment and changes of pitch angle are related when the level of magnetic fluctuations is low, δB/B(0) = (10(-3),10(-2)), where B(0) is the constant and uniform background magnetic field. Stochasticity arises for intermediate fluctuation values and its effect on pitch angle is the isotropization of the distribution function f(α). This is a transient regime during which magnetic moment distribution f(μ) exhibits a characteristic one-sided long tail and starts to be influenced by the onset of spatial parallel diffusion, i.e., the variance <(Δz)(2)> grows linearly in time as in normal diffusion. With strong fluctuations f(α) becomes completely isotropic, spatial diffusion sets in, and the f(μ) behavior is closely related to the sampling of the varying magnetic field associated with that spatial diffusion.

The HMGA1-IGF-I/IGFBP system: a novel pathway for modulating glucose uptake

We previously showed that loss of the high mobility group A1 (HMGA1) protein expression, induced in mice by disrupting the Hmga1 gene, considerably decreased insulin receptor expression in the major target tissues of insulin action, causing a type 2-like diabetic phenotype, in which, however, glucose intolerance was paradoxically associated with increased peripheral insulin sensitivity. Insulin hypersensitivity despite impairment of insulin action supports the existence of molecular adaptation mechanisms promoting glucose disposal via insulin-independent processes. Herein, we provide support for these compensatory pathways/circuits of glucose uptake in vivo, the activation of which under certain adverse metabolic conditions may protect against hyperglycemia. Using chromatin immunoprecipitation combined with protein-protein interaction studies of nuclear proteins in vivo, and transient transcription assays in living cells, we show that HMGA1 is required for gene activation of the IGF-binding proteins 1 (IGFBP1) and 3 (IGFBP3), two major members of the IGF-binding protein superfamily. Furthermore, by using positron emission tomography with (18)F-labeled 2-fluoro-2-deoxy-d-glucose, in combination with the euglycemic clamp with IGF-I, we demonstrated that IGF-I's bioactivity was increased in Hmga1-knockout mice, in which both skeletal muscle Glut4 protein expression and glucose uptake were enhanced compared with wild-type littermates. We propose that, by affecting the expression of both IGFBP protein species, HMGA1 can serve as a modulator of IGF-I activity, thus representing an important novel mediator of glucose disposal.

Reproducibility and accuracy of non-invasive measurement of infarct size in mice with high-resolution PET/CT

BACKGROUND

This study assessed the reproducibility and accuracy of 2-deoxy-2[(18)F]fluoro-D-glucose ((18)F-FDG) for non-invasive quantification of myocardial infarct size in mice by a high-resolution positron emission tomography (PET)/computed tomography (CT) system.

METHODS AND RESULTS

Mice were studied by (18)F-FDG PET/CT 1 week after induction of myocardial infarction by permanent coronary occlusion or sham procedure. In a subset of mice, PET/CT was repeated 2 days apart to assess the reproducibility of infarct size measurements. Histological analysis was used as reference method to validate imaging data. The average difference in infarct size measurements between the first and the second study was -0.42% ± 2.07% (95% confidence interval -2.6 to 1.75) with a repeatability coefficient of 4.05%. At Bland-Altman analysis, the lower and upper limits of agreement between the two repeated studies were -4.46% and 3.63%, respectively, and no correlation between difference and mean was found (P = .89). The concordance correlation coefficient was 0.99 (P < .001) and the intraclass coefficient of correlation was 0.99. A high correlation between PET/CT and histology was found for measurement of infarct size (P < .001). Using Bland-Altman analysis, the mean difference in infarct size measurement (PET/CT minus histology) was 1.9% (95% confidence interval 0.94% to 2.86%).

CONCLUSIONS

In a mice model of permanent coronary occlusion non-invasive measurement of infarct size with high-resolution (18)F-FDG, PET/CT has excellent reproducibility and accuracy. These findings support the use of this methodology in serial studies.

Abstract 5626: FKBP51 is a crucial modulator of melanoma plasticity and promising molecular target for preventing melanoma metastasis

FKBP51, a protein with a relevant role in developmental stages in mammals and other organisms, is highly expressed in melanoma and correlates with tumor aggressiveness and resistance to therapy. We found that FKBP51 positively regulates melanoma cancer stem cell (CSC) phenotype at the transcriptional level. We also found that melanoma CSCs are endowed with epithelial to mesenchimal transition (EMT) traits. The immunochemistry study of 10 primitive cutaneous and 20 brain melanoma metastases showed that melanocytic cells capable of extravasation and subverting the architecture of metastatic tissue display intense FKBP51 nuclear signal and cytoplasmic positivity for the CSC marker nestin. These findings support the conclusion that the genetic programs of cancer stemness and invasiveness overlap in melanoma, and that FKBP51 plays a pivotal role in sustaining such a program. To confirm the role of FKBP51 in melanoma invasion, we utilized an experimental metastasis model. Animal studies were performed in accordance with NIH recommendations and the approval of the local institutional animal research committee. Injecting SAN melanoma cells into the tail vein of IL2γ-NOD-SCID mice produced prominent multifocal lesions in lungs and liver. We systemically administered two separate doses of FKBP51 siRNA to mice after the injection of melanoma cells. Organ colonization was evaluated both in live animals and post mortem. Qualitative PET/CT image analysis demonstrated low FDG uptake limited to small areas in lungs and liver. By contrast, untreated mice had diffuse metastatic liver and lung lesions and high FDG uptake in the same organs. Quantitative analysis performed on PET/CT images revealed that mean standardized uptake values (SUV) in treated mice were significantly lower than in untreated mice, both for lungs and liver. High Frequency Ultrasound examination revealed few or no liver metastases in treated mice versus untreated mice. Post-mortem organ examination showed a dramatic difference between the morphologically preserved organs dissected from treated mice, and severely compromised organs from untreated mice. The histological examination confirmed these findings. Most interestingly, invading cells co-expressed FKBP51 and nestin. Our study suggests a prominent role for FKBP51 in the pathogenesis of metastatic melanoma; we envision that targeting this protein for melanoma metastasis prevention may produce a successful outcome.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 103rd Annual Meeting of the American Association for Cancer Research; 2012 Mar 31-Apr 4; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2012;72(8 Suppl):Abstract nr 5626. doi:1538-7445.AM2012-5626

Meniere's disease might be an autoimmune condition?

OBJECTIVES

To review our current knowledge of the pathogenesis of Meniere's disease, including viral infection and immune system-mediated mechanisms, and to discuss the pathogenesis as it relates to pharmacotherapy.

SYSTEMATIC REVIEW METHODOLOGY

Relevant publications on the aetiopathogenesis, molecular biology, genetics and histopathology of Meniere's disease from 1861 to 2011 were analysed.

RESULTS AND CONCLUSIONS

Meniere's disease is characterised by intermittent episodes of vertigo, fluctuating sensorineural hearing loss, tinnitus, and aural pressure. The aetiology and pathogenesis remain unknown. Proposed theories of causation include viral infections and immune system-mediated mechanisms. The immune response in Meniere's disease is focused on inner ear antigens. Approximately one-third of Meniere's disease cases seem to be of an autoimmune origin although the immunological mechanisms involved are not clear. The diagnosis of autoimmune inner ear disease is based either on clinical criteria or on a positive response to steroids. The antiviral approach has virtually eliminated the use of various surgical methods used in the past. Steroid responsiveness is high, and with prompt treatment, inner ear damage may be reversible. The administration of etanercept improves or stabilises symptoms in treated patients. Treatment of antiphospholipid syndrome can be directed toward preventing thromboembolic events by using antithrombotic medications. Only warfarin has been shown to be effective. Gene therapy can be used to transfer genetic material into inner ear cells using viral vectors and to protect, rescue, and even regenerate hair cells of the inner ear.

Concomitant evaluation of flow-mediated vasodilation and epicardial fat thickness in idiopathic deep venous thrombosis

Flow mediated vasodilation (FMD) evaluates the endothelium-dependent vasodilation, is a reliable marker of arterial endothelial dysfunction and is related to coronary artery disease. Visceral fat predicts an unfavorable cardiovascular and metabolic risk profile in humans and echocardiographic assessment of epicardial fat (EF) is a reliable marker of visceral adiposity. We measured the FMD and EF thickness in 77 subjects, 38 without idiopathic deep vein thrombosis (DVT) (mean age 65.95 ± 16.29 years) and 39 with idiopathic DVT (mean age 65.49 ± 17.22 years). The purpose of this work is to investigate the presence of statistical association between FMD and DVT and between EF thickness and DVT. Furthermore, to account for possible atherosclerosis risk factor unbalances, comparison between FMD and DVT (and between EF and DVT) was assessed using a multivariate logistic regression model which included the following covariates: FMD, EF, age, sex, smoking and the presence of obesity. Subjects without DVT showed significant lower values of EF thickness (9.07 ± 1.89 mm vs 12.32 ± 1.73 mm, p=0.005) and borderline-significant greater values of FMD (9.01 ± 2.77 percent vs 7.47 ± 5.37 percent, p=0.058) as compared to those with DVT. In conclusion, the data presented indicate that subjects affected by spontaneous deep vein thrombosis may have an impaired endothelium-dependent vasodilation, a marker of arterial endothelial dysfunction related to coronary artery disease, and an increased epicardial adipose tissue, a marker of cardiometabolic risk.

On the deconvolution analysis of electrodermal activity in bipolar patients

People affected by bipolar disorders experience alternating states of depression with episodes of mania or hypomania. This mental can lead to a poor handling of daily routines, can worsen personal relationships, and often can be life-threatening. This preliminary study aims at investigating how the autonomic nervous system, in terms of electrodermal activity, responds to specific controlled emotional stimuli in bipolar patients. More specifically, we present here a method to deploy the analysis of ElectroDermal Activity (EDA) to discriminate clinical mood states. EDA was analyzed by using a deconvolution method to separate tonic from phasic components. The three subjects recruited and the experimental protocol used here is part of the European project PSYCHE. Preliminary results show that the bipolar mood states can be related to electrodermal tonic activity.