Doppler ultrasonographic measurements of the lateral digital palmar artery in pregnant mares.

Cardiovascular changes have been reported in late pregnancy in mares. However, there are no data on changes in peripheral blood flow. Doppler ultrasound represents a sensitive method for assessing the blood flow directed to the hoof. The aims of this study were to evaluate the blood flow parameters of the lateral palmar digital artery (LPDA) in pregnant mares and to assess intra- and interrater agreement between two observers with different levels of experience. The LPDAs of pregnant Italian Standardbred mares were examined. The vessels were located with B-mode ultrasound and analyzed with color and pulsed wave Doppler. The following parameters were recorded by the operators: heart rate (HR), peak systolic velocity (PSV), end-diastolic velocity (EDV), and resistive index (RI). Measurements were performed between 2 and 3 months of gestation (T1), in the last month of pregnancy (T2) and a week after delivery (T3). Seventeen mares aged 3-18 years met the inclusion criteria. Ultrasound examinations of the LPDA were subjectively easy to perform and well tolerated by the mares. Interrater and intrarater agreement were good and moderate, respectively. The HR was higher at T2 than at T1 and T3. The PSV and RI changed significantly during pregnancy, with higher values at T2 and T3, whereas the EDV remained unchanged throughout the examination. Doppler examination showed that peripheral flow changes were present in mares in late pregnancy. However, the persistence of higher values after delivery invites further investigation to assess the correlation between metabolic/endocrine changes related to pregnancy and Doppler parameters.

The heart to single vertebra ratio: A new objective method for radiographic assessment of cardiac silhouette size in dogs.

Vertebral heart size (VHS) is widely determined in clinical practice as an objective method to assess the cardiac silhouette dimensions. However, a key limitation is that it is difficult to determine VHS in dogs with vertebral alterations. This retrospective, method comparison, observer agreement study sought to overcome this limitation by using the heart-to-single vertebra ratio (HSVR), by evaluating the level of agreement between VHS and HSVR, as well as the intra- and inter-observer agreement for HSVR. Three independent observers retrospectively evaluated thoracic radiographs obtained over a set time period. Exclusion criteria were the presence of alterations of the thoracic spine and the inability to clearly outline the cardiac silhouette. The lengths of the vertebral bodies, from the fourth to eighth thoracic vertebra, and VHS were measured on each radiograph. The HSVR was calculated by dividing the sum of the cardiac long and short axes by the length of each vertebral body. Eighty dogs of different breeds were included in the final analysis. Lin's concordance correlation coefficients revealed strong correlations between VHS and HSVR (0.91-0.96), and the Bland-Altman plots showed low bias (0.01-0.2) between the methods. The mean absolute errors indicated low average magnitudes of error (0.11-0.28). The intraclass correlation coefficients showed good to excellent inter-observer (0.87-0.92; P = 0.000) and intra-observer (0.87-0.99; P < .001) agreement. In the authors' opinion, this new method, which is less time consuming and more objective, could offer a valuable alternative to VHS.

Description of a low-cost picture archiving and communication system based on network-attached storage.

High costs for installing, maintaining, and updating a standard picture archiving and communication system (PACS) can be prohibitive for small/medium-sized veterinary facilities. The aims of this prospective, exploratory study were to describe the design, implementation, and author experiences for 1 year's use of a low-cost PACS based on network-attached storage. The system described here was easily installed and resiliently stored redundant copies of data. It excellently balanced data recovery, system speed, security, and available memory for storage. A virtual private network also allowed off-site data review. This system can also be used for future off-site backup of data in the cloud.

The phosphatase Shp1 interacts with and dephosphorylates cortactin to inhibit invadopodia function.

BACKGROUND: Invadopodia are actin-based cell-membrane protrusions associated with the extracellular matrix degradation accompanying cancer invasion. The elucidation of the molecular mechanisms leading to invadopodia formation and activity is central for the prevention of tumor spreading and growth. Protein tyrosine kinases such as Src are known to regulate invadopodia assembly, little is however known on the role of protein tyrosine phosphatases in this process. Among these enzymes, we have selected the tyrosine phosphatase Shp1 to investigate its potential role in invadopodia assembly, due to its involvement in cancer development. METHODS: Co-immunoprecipitation and immunofluorescence studies were employed to identify novel substrate/s of Shp1AQ controlling invadopodia activity. The phosphorylation level of cortactin, the Shp1 substrate identified in this study, was assessed by immunoprecipitation, in vitro phosphatase and western blot assays. Short interference RNA and a catalytically-dead mutant of Shp1 expressed in A375MM melanoma cells were used to evaluate the role of the specific Shp1-mediated dephosphorylation of cortactin. The anti-invasive proprieties of glycerophosphoinositol, that directly binds and regulates Shp1, were investigated by extracellular matrix degradation assays and in vivo mouse model of metastasis. RESULTS: The data show that Shp1 was recruited to invadopodia and promoted the dephosphorylation of cortactin at tyrosine 421, leading to an attenuated capacity of melanoma cancer cells to degrade the extracellular matrix. Controls included the use of short interference RNA and catalytically-dead mutant that prevented the dephosphorylation of cortactin and hence the decrease the extracellular matrix degradation by melanoma cells. In addition, the phosphoinositide metabolite glycerophosphoinositol facilitated the localization of Shp1 at invadopodia hence promoting cortactin dephosphorylation. This impaired invadopodia function and tumor dissemination both in vitro and in an in vivo model of melanomas. CONCLUSION: The main finding here reported is that cortactin is a specific substrate of the tyrosine phosphatase Shp1 and that its phosphorylation/dephosphorylation affects invadopodia formation and, as a consequence, the ability of melanoma cells to invade the extracellular matrix. Shp1 can thus be considered as a regulator of melanoma cell invasiveness and a potential target for antimetastatic drugs. Video abstract.

A computed tomography-based method for the assessment of canine retrobulbar cone volume for ophthalmic anaesthesia.

OBJECTIVE: To develop a comprehensive formula for calculating the volume of local anaesthetic solution used for retrobulbar anaesthesia in dogs with different skull morphologies. STUDY DESIGN: Retrospective cohort imaging study. ANIMALS: Skull computed tomography (CT) images of 188 dogs of different breeds collected between January 2009 and December 2017. METHODS: Anatomical integrity of the orbit and adjacent structures, presenting complaint, clinical signs and CT findings were verified to exclude ocular abnormalities. The volume of the retrobulbar cone of 376 eyes was calculated using CT scans of the dogs' skulls. Additional data recorded included morphology of the skull, body weight, sex and size of the dogs, all of which were matched for possible association to the retrobulbar cone volume through univariable and multivariable linear regression models. Results of linear regression models were expressed as estimated beta coefficients with the corresponding 95% confidence intervals (95% CIs). RESULTS: Using univariate analysis, the retrobulbar cone volume was positively associated with weight and male sex. In addition, brachycephalic and dolichocephalic dogs showed a larger retrobulbar cone volume than mesocephalic dogs, while sex was no longer significantly associated with the retrobulbar cone volume. In multivariate analysis, when considering all variables in the model, weight emerged as the strongest predictor (beta coefficient: 0.062 mL kg-1, 95% CI: 0.056-0.067 mL kg-1, p < 0.001). CONCLUSIONS: and clinical relevance In the veterinary literature, there is no agreement on the precise volume of local anaesthetic solution that should be used to achieve intraconal retrobulbar anaesthesia in dogs. Here we suggest a formula to calculate the retrobulbar cone volume and, accordingly, the injection volume of local anaesthetic solution for effective retrobulbar anaesthesia.

Ultrasonographic measurement of kidney-to-aorta parameters in Whippets.

In a previous study, an ultrasonographic method to assess kidney size in dogs as a ratio of kidney length to aortic luminal diameter (KL/AoD ratio) was proposed. The main limitation of this method was the wide range of normal values (5.5-9.1), which resulted in poor sensitivity and specificity. The aim of this prospective, observational, reference interval study was to determine whether the KL/AoD normal cut-off values in a single breed (Whippets) would have a narrower range than the previously reported normal reference ranges. The influence of sex, age, weight, and side on kidney length (KL) and of sex, age, weight, and scanning plane (longitudinal vs transversal) on aortic luminal diameter (AoD) were also investigated. Thirty-six clinically healthy Whippets (16 males, 20 females) without ultrasonographic renal lesions were included in this study. The 95% confidence interval of mean KL/AoD was found to be narrower than the previously reported range (ie, 6.3-6.9 versus 5.5-9.1). This was considered to be especially notable in that the KL in this breed exhibits marked sexual dimorphism. The KL/AoD ratio did not differ between right versus left sides or male versus female sexes in Whippets (P > .05). Findings from the current study provided KL/AoD ratio normal reference range cut-off values for future use in Whippets and supported the use of breed-specific KL/AoD ratio values for characterizing abnormal renal size in other canine breeds.

FOXE1 Gene Dosage Affects Thyroid Cancer Histology and Differentiation In Vivo.

The transcription factor Forkhead box E1 (FOXE1) is a key player in thyroid development and function and has been identified by genome-wide association studies as a susceptibility gene for papillary thyroid cancer. Several cancer-associated polymorphisms fall into gene regulatory regions and are likely to affect FOXE1 expression levels. However, the possibility that changes in FOXE1 expression modulate thyroid cancer development has not been investigated. Here, we describe the effects of FOXE1 gene dosage reduction on cancer phenotype in vivo. Mice heterozygous for FOXE1 null allele (FOXE1+/-) were crossed with a BRAFV600E-inducible cancer model to develop thyroid cancer in either a FOXE1+/+ or FOXE1+/- genetic background. In FOXE1+/+ mice, cancer histological features are quite similar to that of human high-grade papillary thyroid carcinomas, while cancers developed with reduced FOXE1 gene dosage maintain morphological features resembling less malignant thyroid cancers, showing reduced proliferation index and increased apoptosis as well. Such cancers, however, appear severely undifferentiated, indicating that FOXE1 levels affect thyroid differentiation during neoplastic transformation. These results show that FOXE1 dosage exerts pleiotropic effects on thyroid cancer phenotype by affecting histology and regulating key markers of tumor differentiation and progression, thus suggesting the possibility that FOXE1 could behave as lineage-specific oncogene in follicular cell-derived thyroid cancer.

Helper-dependent adenovirus-mediated gene transfer of a secreted LDL receptor/transferrin chimeric protein reduces aortic atherosclerosis in LDL receptor-deficient mice.

Familial hypercholesterolemia (FH) is a genetic hyperlipidemia characterized by elevated concentrations of plasma LDL cholesterol. Statins are not always effective for the treatment of FH patients; unresponsive patients have poor prognosis and rely on LDL apheresis. In the past, we developed safe and effective gene therapy strategies for the expression of anti-atherogenic proteins using PEGylated helper-dependent adenoviral (HD-Ad) vectors. We recently developed a HD-Ad vector for the expression of the soluble form of the extracellular portion of the human LDL receptor (LDLR) fused with a rabbit transferrin dimer (LDLR-TF). We evaluated the efficacy of the LDLR-TF chimeric protein  in CHOLDLA7, a cell line lacking LDLR expression, restoring the ability to uptake LDL. Subsequently, we administered intravenously 1 × 10E13 vp/kg of this vector in LDLR-deficient mice and observed amelioration of lipid profile and reduction of aortic atherosclerosis. Finally, we studied LDL distribution after HD-Ad vector-mediated expression of LDLR-TF in LDLR-deficient mice and found LDL accumulation in liver, and in heart and intestine. These results support the possibility of lowering LDL-C levels and reducing aortic atherosclerosis using a secreted therapeutic transgene; the present strategy potentially can be modified and adapted to non-systemic gene transfer with expression of the secreted chimeric protein in muscle or other tissues. Intramuscular or local administration strategies could improve the safety profile of this strategy and facilitate applicability.

Junctional adhesion molecule-A is down-regulated in anaplastic thyroid carcinomas and reduces cancer cell aggressiveness by modulating p53 and GSK3 α/ß pathways.

Junctional adhesion molecule A (JAM-A) is a transmembrane protein that contributes to different biological process, including the epithelial to mesenchymal transition (EMT). Through an EMT profiler array, we explored the molecular players associated with human thyroid cancer progression and identified JAM-A as one of the genes mostly deregulated. The quantitative real-time polymerase chain reaction and immunohistochemistry analyses showed that downregulation of JAM-A occurred in anaplastic thyroid carcinoma (ATC) compared with normal thyroid (NT) and papillary thyroid carcinoma (PTC) tissues and correlated with extrathyroid infiltration, tumor size, and ATC histotype. In ATC cell lines, JAM-A restoration suppressed malignant hallmarks of transformation including cell proliferation, motility, and transendothelial migration. Accordingly, knockdown of JAM-A enhanced thyroid cancer cell proliferation and motility in PTC cells. Through the proteome profiler human phospho-kinase array, we demonstrated that higher expression of JAM-A was associated with a significant increased level of phosphorylation of p53 and GSK3 α/ß proteins. In conclusion, our findings highlight a novel role of JAM-A in thyroid cancer progression and suggest that JAM-A restoration could have potential clinical relevance in thyroid cancer treatment.

Measurement of [123I]FP-CIT binding to the dopamine transporter (DAT) in healthy mouse striatum using dedicated small animal SPECT imaging: feasibility, optimization and validation.

BACKGROUND: In-vivo imaging of dopamine transporter (DAT), a reliable marker of degeneration of nigrostriatal dopaminergic innervation, has gained increasing interest in preclinical neurodegenerative research for studying disease mechanisms and testing new therapeutic strategies. We assessed the feasibility and the reliability of in vivo and ex vivo quantification of Methyl (3S,4S,5R)-8-(3-fluoropropyl)-3-(4-iodophenyl)-8-azabicyclo[3.2.1]octane-4-carboxylate ([123I]FP-CIT) binding to striatal DAT sites in mouse brain. METHODS: Dedicated small animal single-photon emission computed tomography (SPECT) images of [123I]FP-CIT binding were obtained in 3 groups of healthy mice: untreated (N.=6), pre-treated with lugol solution (N.=4), and pre-treated with selective dopamine transporter uptake inhibitor GBR12909 (N.=4). Ex-vivo autoradiography studies were performed at the end of SPECT studies with phosphor image system in 4 out of the 6 untreated mice and in all mice pre-treated with lugol. Regions of interest were defined over the striatum. The specific binding (SB) was calculated using the cerebral cortex as reference region. RESULTS: SPECT images in untreated mice showed high [123I]FP-CIT uptake in the striatum and extracerebral regions. Lugol pretreatment improved striatal images quality decreasing salivary and thyroid glands uptake. SB was higher (P<0.0001) in mice pre-treated with lugol (5.97±0.60) than in untreated mice (2.25±0.28). Autoradiography showed similar SB findings in untreated (2.27±0.33) and lugol-treated (4.27±0.57) mice (P<0.0001). In-vivo striatal 123I-FP-CIT SB and ex-vivo striatal 123I-FP-CIT SB were significantly correlated (r=0.87; P<0.0001). SPECT competition studies showed a significant (P<0.0001) reduction of [123I]FP-CIT SB in the striatum after GBR12909. CONCLUSIONS: We demonstrated the feasibility of [123I]FP-CIT imaging of the normal mouse brain using small-animal SPECT without pinhole collimators. The reliability of quantitative measurement of striatal [123I]FP-CIT SB is supported by competition studies showing measurable inhibition of uptake induced by GBR12909 and by the strong correlation between in vivo and ex vivo striatal [123I]FP-CIT SB. Our data also demonstrate that pre-treatment with lugol might improve striatal [123I]FP-CIT SB in mice.

Multimodal imaging for a theranostic approach in a murine model of B-cell lymphoma with engineered nanoparticles.

Nanoparticles (NPs) are a promising tool for in vivo multimodality imaging and theranostic applications. Hyaluronic acid (HA)-based NPs have numerous active groups that make them ideal as tumor-targeted carriers. The B-lymphoma neoplastic cells express on their surfaces a clone-specific immunoglobulin receptor (Ig-BCR). The peptide A20-36 (pA20-36) selectively binds to the Ig-BCR of A20 lymphoma cells. In this work, we demonstrated the ability of core-shell chitosan-HA-NPs decorated with pA20-36 to specifically target A20 cells and reduce the tumor burden in a murine xenograft model. We monitored tumor growth using high-frequency ultrasonography and demonstrated targeting specificity and kinetics of the NPs via in vivo fluorescent reflectance imaging. This result was also confirmed by ex vivo magnetic resonance imaging and confocal microscopy. In conclusion, we demonstrated the ability of NPs loaded with fluorescent and paramagnetic tracers to act as multimodal imaging contrast agents and hence as a non-toxic, highly specific theranostic system.

Advances in multimodal molecular imaging.

Preclinical molecular imaging is an emerging field. Improving the ability of scientists to study the molecular basis of human pathology in animals is of the utmost importance for future advances in all fields of human medicine. Moreover, the possibility of developing new imaging techniques or of implementing old ones adapted to the clinic is a significant area. Cardiology, neurology, immunology and oncology have all been studied with preclinical molecular imaging. The functional techniques of photoacoustic imaging (PAI), fluorescence molecular tomography (FMT), positron emission tomography (PET), and single photon emission computed tomography (SPECT) in association with each other or with the anatomic reference provided by computed tomography (CT) as well as with anatomic and functional information provided by magnetic resonance (MR) have all been proficiently applied to animal models of human disease. All the above-mentioned imaging techniques have shown their ability to explore the molecular mechanisms involved in animal models of disease. The clinical translatability of most of the techniques motivates the ongoing study of their possible fields of application. The ability to combine two or more techniques allows obtaining as much information as possible on the molecular processes involved in pathologies, reducing the number of animals necessary in each experiment. Merging molecular probes compatible with various imaging technique will further expand the capability to achieve the best results.

Advances in molecular preclinical therapy mediated by imaging.

Several advances have been made toward understanding the biology of cancer and most of them are due to robust genetic studies that led to the scientific recognition that although many patients have the same type of cancer their tumors may have harbored different molecular alterations. Personalized therapy and the development of advanced techniques of preclinical imaging and new murine models of disease are emerging concepts that are allowing mapping of disease markers in vivo and in some cases also receptor targeted therapy. Aim of this review is to illustrate some emerging models of disease that allow patient tumor implantation in mice for subsequent drug testing and advanced approaches for therapy mediated by preclinical imaging. In particular we discuss targeted therapy mediated by high frequency ultrasound and magnetic resonance, two emerging techniques in molecular preclinical therapy.

Preclinical Imaging for the Study of Mouse Models of Thyroid Cancer.

Thyroid cancer, which represents the most common tumors among endocrine malignancies, comprises a wide range of neoplasms with different clinical aggressiveness. One of the most important challenges in research is to identify mouse models that most closely resemble human pathology; other goals include finding a way to detect markers of disease that common to humans and mice and to identify the most appropriate and least invasive therapeutic strategies for specific tumor types. Preclinical thyroid imaging includes a wide range of techniques that allow for morphological and functional characterization of thyroid disease as well as targeting and in most cases, this imaging allows quantitative analysis of the molecular pattern of the thyroid cancer. The aim of this review paper is to provide an overview of all of the imaging techniques used to date both for diagnosis and theranostic purposes in mouse models of thyroid cancer.

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.

Identification and characterization of a new potent inhibitor targeting CtBP1/BARS in melanoma cells.

BACKGROUND: The C-terminal-binding protein 1/brefeldin A ADP-ribosylation substrate (CtBP1/BARS) acts both as an oncogenic transcriptional co-repressor and as a fission inducing protein required for membrane trafficking and Golgi complex partitioning during mitosis, hence for mitotic entry. CtBP1/BARS overexpression, in multiple cancers, has pro-tumorigenic functions regulating gene networks associated with "cancer hallmarks" and malignant behavior including: increased cell survival, proliferation, migration/invasion, epithelial-mesenchymal transition (EMT). Structurally, CtBP1/BARS belongs to the hydroxyacid-dehydrogenase family and possesses a NAD(H)-binding Rossmann fold, which, depending on ligands bound, controls the oligomerization of CtBP1/BARS and, in turn, its cellular functions. Here, we proposed to target the CtBP1/BARS Rossmann fold with small molecules as selective inhibitors of mitotic entry and pro-tumoral transcriptional activities. METHODS: Structured-based screening of drug databases at different development stages was applied to discover novel ligands targeting the Rossmann fold. Among these identified ligands, N-(3,4-dichlorophenyl)-4-{[(4-nitrophenyl)carbamoyl]amino}benzenesulfonamide, called Comp.11, was selected for further analysis. Fluorescence spectroscopy, isothermal calorimetry, computational modelling and site-directed mutagenesis were employed to define the binding of Comp.11 to the Rossmann fold. Effects of Comp.11 on the oligomerization state, protein partners binding and pro-tumoral activities were evaluated by size-exclusion chromatography, pull-down, membrane transport and mitotic entry assays, Flow cytometry, quantitative real-time PCR, motility/invasion, and colony assays in A375MM and B16F10 melanoma cell lines. Effects of Comp.11 on tumor growth in vivo were analyzed in mouse tumor model. RESULTS: We identify Comp.11 as a new, potent and selective inhibitor of CtBP1/BARS (but not CtBP2). Comp.11 directly binds to the CtBP1/BARS Rossmann fold affecting the oligomerization state of the protein (unlike other known CtBPs inhibitors), which, in turn, hinders interactions with relevant partners, resulting in the inhibition of both CtBP1/BARS cellular functions: i) membrane fission, with block of mitotic entry and cellular secretion; and ii) transcriptional pro-tumoral effects with significantly hampered proliferation, EMT, migration/invasion, and colony-forming capabilities. The combination of these effects impairs melanoma tumor growth in mouse models.  CONCLUSIONS: This study identifies a potent and selective inhibitor of CtBP1/BARS active in cellular and melanoma animal models revealing new opportunities to study the role of CtBP1/BARS in tumor biology and to develop novel melanoma treatments.

Btk regulation in human and mouse B cells via protein kinase C phosphorylation of IBtkγ.

The inhibitor of Bruton tyrosine kinase γ (IBtkγ) is a negative regulator of the Bruton tyrosine kinase (Btk), which plays a major role in B-cell differentiation; however, the mechanisms of IBtkγ-mediated regulation of Btk are unknown. Here we report that B-cell receptor (BCR) triggering caused serine-phosphorylation of IBtkγ at protein kinase C consensus sites and dissociation from Btk. By liquid chromatography and mass-mass spectrometry and functional analysis, we identified IBtkγ-S87 and -S90 as the critical amino acid residues that regulate the IBtkγ binding affinity to Btk. Consistently, the mutants IBtkγ carrying S87A and S90A mutations bound constitutively to Btk and down-regulated Ca(2+) fluxes and NF-κB activation on BCR triggering. Accordingly, spleen B cells from Ibtkγ(-/-) mice showed an increased activation of Btk, as evaluated by Y551-phosphorylation and sustained Ca(2+) mobilization on BCR engagement. These findings identify a novel pathway of Btk regulation via protein kinase C phosphorylation of IBtkγ.

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.

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.

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.