Greater Signal Intensity Research Articles

Achieving NPVR ≥ 80% as technical success of high-intensity focused ultrasound ablation for uterine fibroids: a cohort study

ObjectiveTo report the long-term re-intervention of patients with uterine fibroids after ultrasound-guided high-intensity focused ultrasound (USgHIFU) ablation and to analyse the influencing factors of re-intervention in patients in the NPVR ≥ 80% group.Materials and methodsPatients with a single uterine fibroid who underwent USgHIFU at our hospital from January 2012 to December 2019 were enrolled. The patients were divided into four groups according to different nonperfusion volume ratio (NPVR). Kaplan–Meier survival curve was used to analyse long-term re-intervention in different NPVR groups, and Cox regression was used to analyse the influencing factors of re-intervention in the NPVR ≥ 80% group.Main resultsA total of 1,257 patients were enrolled, of whom 920 were successfully followed up. The median follow-up time was 88 months, and the median NPVR was 85.0%. The cumulative re-intervention rates at 1, 3, 5, 8 and 10 years after USgHIFU were 3.4%, 11.8%, 16.8%, 22.6% and 24.1%, respectively. The 10-year cumulative re-intervention rate was 37.3% in the NPVR < 70% group, 31.0% in the NPVR 70–79% group, 18.2% in the NPVR 80–89% group and 17.8% in the NPVR ≥ 90% group (P < 0.05). However, no difference was found between the group of NPVR 80−89% and the group of NPVR ≥ 90% (P = 0.499). Age of patients and signal intensity on T2-weighted imaging (T2WI) of tumours were found to be independent risk factors for long-term re-intervention in the NPVR ≥ 80% group. A younger age and greater signal intensity on T2W images corresponded to a greater risk of re-intervention.ConclusionUSgHIFU, an alternative treatment for uterine fibroids, has reliable long-term efficacy. NPVR ≥ 80% can be used as a sign of technical success, which can reduce re-intervention rates. However, an important step is to communicate with patients in combination with the age of patients and the signal intensity on T2WI of fibroids.Trial registrationThis retrospective study was approved by the ethics committee at our institution (Registration No. HF2023001; Date: 06/04/2023). The Chinese Clinical Trial Registry provided full approval for the study protocol (Registration No. CHiCTR2300074797; Date: 16/08/2023).

Serum biomarkers of liver fibrosis identify globus pallidus vulnerability

The CNS manifestation of chronic liver disease can include magnetic resonance (MR) signal hyperintensities in basal ganglia structures. Here, relations between liver (serum-derived fibrosis scores) and brain (regional T1-weighted signal intensities and volumes) integrity were evaluated in a sample of 457 individuals including those with alcohol use disorders (AUD), people living with human immunodeficiency virus (HIV), those comorbid for AUD and HIV, and healthy controls. Liver fibrosis was identified from cutoff scores as follows: aspartate aminotransferase to platelet ratio index (APRI) > 0.7 in 9.4% (n = 43) of the cohort; fibrosis score (FIB4) > 1.5 in 28.0% (n = 128) of the cohort; and non-alcoholic fatty liver disease fibrosis score (NFS) > -1.4 in 30.2% (n = 138) of the cohort. Presence of serum-derived liver fibrosis was associated with high signal intensities selective to basal ganglia (i.e., caudate, putamen, and pallidum) structures. High signal intensities in the pallidum, however, explained a significant portion of the variance in APRI (25.0%) and FIB4 (23.6%) cutoff scores. Further, among the regions evaluated, only the globus pallidus showed a correlation between greater signal intensity and smaller volume (r = -0.44, p <.0001). Finally, higher pallidal signal intensity correlated worse ataxia (eyes open ρ = -0.23, p =.0002; eyes closed ρ = -0.21, p =.0005). This study suggests that clinically relevant serum biomarkers of liver fibrosis such as the APRI may identify individuals vulnerable to globus pallidus pathology and contribute to problems with postural balance.

Development of a Low-Cost Lateral Flow Assay for Rapid Detection of Vibrio Cholerae

Cholera is an acute, often fatal diarrheal disease that primarily affects areas with poor sanitation and unclean water. Cholera is caused by toxigenic strains of Vibrio cholerae (V. cholerae), which cause the body to rapidly dehydrate upon colonizing the intestine. The WHO estimates that 2.9 million people contract cholera each year, resulting in approximately 95000 deaths [1].Current methods for detection of V. cholerae are either inferential (detection of fecal coliforms or monitoring weather patterns) or diagnosed after an infection (stool tests) [2]. Even methods that have been developed for direct detection of V. cholerae fall short of detecting environmental concentrations of the bacterium (10-104 CFU/mL) [3]; a lateral flow assay (LFA) using gold nanoparticle-labelled antibodies for the simultaneous detection of O1 and O139 strains of V. cholerae achieved a limit of detection of 108 CFU/mL for O1 and 107 CFU/mL for O139 [4]. The current work aims to develop an LFA for the detection of V. cholerae at environmental conditions in drinking water under limited resource settings. By incorporating novel aptamers as antigen detecting agents, carbon nanoparticles as colorimetric indicators, and N-acetylglucosamine (GlcNAc)–a known chemoattractant for V. cholerae –in the sample pad, the limit of detection will be improved without the need for lengthy preprocessing steps or costly reagents.The antigen detection agent employed in the LFA is the aptamer V.ch27 which was identified by Mojarad and Gargaria [5]. This aptamer was shown to have a favourable secondary structure at 21°C and high binding affinity to the surface of V. cholerae bacteria. Aptamers are a synthetic alternative to conventionally used antibodies for this application. They exhibit specificities comparable to those of monoclonal antibodies, are cheaper to synthesize, and can be easily immobilized to surfaces via biotin-avidin complexing.Amorphous carbon nanoparticles (ACNPs) were chosen as the colorimetric indicator for the assay due to their strong black color and low cost [6]. For instance, carbon nanoparticles have shown a 100-fold decrease in the limit of detection for dengue fever antigen when compared to gold nanoparticles [7]. The ACNPs were synthesized by collecting the soot from burning candles followed by size selection by centrifugation, as previously described Zhang et al [8].The chemotaxis of V. cholerae to GlcNAc is well documented in literature [9]. The sample pad of the LFA contains a GlcNAc solution which diffuses into the water sample. V. cholerae swim up the GlcNAc concentration gradient and accumulate in high concentrations at the sample pad. This in turn results in a high concentration of analyte entering the assay, and consequently, a greater signal intensity. Previous studies have shown that chemotaxis can be exploited to collect nearly all of the bacteria in a 100 mL water sample [10,11].The fabricated LFA device will provide a rapid, accessible, and low-cost platform for V. cholerae detection in the water sources available to rural and low-income communities, without the need for technical training or well-established laboratory infrastructure. Successful implementation of the device will result in the overall reduction of global deaths due to cholera, as well as provide the framework for future preventative initiatives aimed towards cholera outbreak prediction and monitoring.

Probing Methionine Uptake in Live Cells by Deuterium Labeling and Stimulated Raman Scattering.

The small biomolecule methionine (Met) is a fundamental amino acid required for a vast range of biological processes such as protein synthesis, cancer metabolism, and epigenetics. However, it is still difficult to visualize the subcellular distribution of small biomolecules including Met in a minimally invasive manner. Here, we demonstrate stimulated Raman scattering (SRS) imaging of cellular uptake of deuterated methionine (d8-Met) in live HeLa cells by way of comparison to the previously used alkyne-labeled Met analogue─homopropargylglycine (Hpg). We show that the solutions of d8-Met and Hpg have similar SRS signal intensities. Furthermore, by careful image analysis with background subtraction, we succeed in the SRS imaging of cellular uptake of d8-Met with a much greater signal intensity than Hpg, possibly reflecting the increased and minimally invasive uptake kinetics of d8-Met compared with Hpg. We anticipate that d8-Met and other deuterated biomolecules will be useful for investigating metabolic processes with subcellular resolution.

Intracolic ultrasound molecular imaging: a novel method for assessing colonic tumor necrosis factor-\u03b1 expression in inflammatory bowel disease

BackgroundWhile anti-tumor necrosis factor alpha (TNF-α) therapy has been proven effective in inflammatory bowel disease (IBD), approximately 40% of patients lose the response. Transmembrane TNF-α (mTNF-α) expression in the intestinal mucosa is correlated with therapeutic efficacy, and quantification of mTNF-α expression is significant for predicting response. However, conventional intravenous application of microbubbles is unable to assess mTNF-α expression in intestinal mucosa. Herein, we proposed intracolic ultrasound molecular imaging with TNF-α-targeted microbubbles (MBTNF-α) to quantitatively detect mTNF-α expression in the intestinal mucosa.MethodsMBTNF-α was synthesized via a biotin–streptavidin bridging method. TNF-α-targeted ultrasound imaging was performed by intracolic application of MBTNF-α to detect mTNF-α expression in surgical specimens from a murine model and patients with IBD. Linear regression analyses were performed to confirm the accuracy of quantitative targeted ultrasound imaging.ResultsOn quantitative TNF-α-targeted ultrasound images, a greater signal intensity was observed in the mouse colons with colitis ([1.96 ± 0.45] × 106 a.u.) compared to that of the controls ([0.56 ± 0.21] × 106 a.u., P < 0.001). Targeted US signal intensities and inflammatory lesions were topographically coupled in mouse colons. Linear regression analyses in specimens of mice and patients demonstrated significant correlations between the targeted ultrasound signal intensity and mTNF-α expression (both P < 0.001). Furthermore, TNF-α-targeted ultrasound imaging qualitatively distinguished the varying inflammatory severity in intestinal specimens from IBD patients.ConclusionIntracolic ultrasound molecular imaging with MBTNF-α enables quantitative assessment of mTNF-α expression. It may be a potential tool for facilitating the implementation of personalized medicine in IBD.

Effectiveness of antibody specific for heat-processed milk proteins and incurred calibrants for ELISA-based quantification of milk in dark chocolate matrices

Although undeclared milk is prevalent in chocolate products, processing-induced alterations of milk proteins and matrix composition prevent reliable quantification of this allergen by current enzyme-linked immunosorbent assays (ELISA). High affinity antibodies (Abs) are required to detect milk protein epitopes that may be modified by manufacturing procedures. We therefore developed an Ab specific for heat-processed milk proteins (HPMP), which might allow enhanced milk quantification in processed complex matrices, including chocolate. When characterizing HPMP-Ab by immunoblot analysis, greater signal intensities were observed with heat modified proteins. Using a sandwich (s)-ELISA, HPMP-Ab reacted with high affinity to purified major milk proteins, proteins extracted from milk-derived ingredients and reference materials subjected to several thermal processing procedures. Milk-incurred cookies (0–17.7 ppm) and tempered dark chocolate samples (62% cacao: 0–134 ppm; 100% cacao: 0–75 ppm) were assessed using HPMP-Ab in a revised s-ELISA. To optimize protein extraction, samples were defatted with hexane; cookies were then extracted using a high salt buffer (HSB)/1% Tween (T)-20 while chocolate samples were extracted using HSB/1%T-20/5% polyvinylpyrrolidone (PVP)/1% fish gelatin. Despite reliable detection of milk proteins using incurred cookies and tempered 62% dark chocolate samples, as shown by acceptable dynamic ranges of the HPMP-Ab binding curves, high baseline absorbance/background persisted using 100% dark chocolate samples. The HPMP-Ab ELISA was highly specific; no cross reactivity was observed when testing a broad range of food commodities using incurred cookies as calibrants. The HPMP-Ab demonstrated the capacity to detect declared milk proteins in products containing a variety of milk-derived ingredients and undeclared milk proteins in products with precautionary labeling when used to analyze chocolate market samples (up to 85% cacao). Milk proteins were also detected in cross-contact samples produced on equipment used to manufacture milk chocolate, utilizing tempered 62% dark chocolate samples as calibrants. Our results establish the benefits of using HPMP-Ab and matrix-specific incurred calibrants for milk quantification in chocolate matrices by ELISA.

Metabolic profiling of organic acids in urine samples of Cri Du Chat syndrome individuals by gas chromatography-mass spectrometry

Cri Du Chat (CDC) syndrome is a rare genetic condition caused by the deletion of genetic material on the small arm (the p arm) of chromosome 5. A high-pitched cry that sounds like that of a cat, dysmorphic characteristics, and cytogenetic methods are often used for diagnosing the syndrome. In this study, we applied GC–MS analysis for determining organic acids in urine from 17 control volunteers without CDC syndrome, and from 16 individuals with the CDC syndrome in order to determine the profile of organic acids and biochemical pathways alterations resulting from this genetic condition. First, performing multivariate data analysis selected the best method for extracting organic acids with greater signal intensities and good reproducibility. After selection, multivariate (PLS-DA) and univariate (Mann-Whitney test) data analysis discriminated the metabolites responsible for separation between groups. Nine organic acid metabolites had values of VIP ≥ 1.0 and p-values ≤ 0.05, with highest intensities in the samples from CDC individuals, indicating the strongest discriminative power (tricarballylic acid, indoleacetic acid, anthranilic acid, 4-hydroxyphenylacetic acid, 4-hydroxybenzoic acid, 4-hydroxyhippuric acid, pantothenic acid, homovanillic acid, and vanillylmandelic acid). These metabolites are involved in several biochemical pathways like in the tyrosine and phenylalanine metabolism, as well as the tryptophan metabolism, which could be associated (i) to some neuropsychiatric alterations commonly observed in CDC individuals, (ii) to exogenous compounds related to transformation products by intestinal microbial, and (iii) to a possible deficiency in enzyme activity due to the syndrome.

Abstract 1375: Multiplex gene expression using the HyCEAD assay in CTCs isolated with the Parsortix™ system

Abstract Background: Discrimination between benign and malignant pelvic masses by gene expression profiling of circulating tumor cells (CTCs) may provide information to assist in treatment decisions and improve outcomes. CTCs can be isolated and harvested from blood based on cell size and deformability using the Parsortix™ system. Because the number of CTCs in the blood of pelvic mass patients suspected of having ovarian malignancies is likely very low, gene expression profiling of these CTCs requires a highly sensitive detection system that is tolerant of the presence of normal nucleated blood cells. Objective: To assess the suitability of the HyCEAD assay for gene expression profiling of cells in Parsortix harvests. HyCEAD (Hybrid Capture Enrichment Amplification and Detection) is a fast and simple method for the simultaneous analysis of 100 or more mRNA species captured from cell lysates. The products of the multiplex amplification with HyCEAD can be quantified by hybridization on a flow-through chip. Methods: Multiple HyCEAD primer/probe sets were designed for 125 relevant genes, and purified total RNA or lysates from Parsortix harvests were processed with the HyCEAD assay. Primer/probe sets were screened using total RNA from cell lines and ovarian cancer tissues. Genes with significant expression in white blood cells were culled from the gene set. A set of non-human poly-adenylated mRNA molecules (separately quantified using digital droplet PCR) were used as spike-in standards to assess absolute sensitivity. CaOV3 cells spiked into blood from normal healthy volunteers (NHVs) were used as a model system for sensitivity analyses. Results: Many genes were identified that yielded substantially greater signal intensities in harvests from HNV blood spiked with CaOV3 cells relative to the unspiked blood samples. The expression levels could be quantified over a signal intensity range of 2.5 log10 units. Small numbers of non-human standard molecules could be detected; stochastic detection failures were observed when five or fewer molecules of the standards were assayed (dropout level). CVs in repeatability experiments were typically less than 20% with numbers of standard molecules greater than the dropout level. CVs in repeatability measurements of human genes related to ovarian cancer in spiked Parsortix harvests averaged about 25%. CVs were greater between assays of Parsortix harvests of different HNVs, reflecting in part biological variability and variation of the number of cells actually spiked into the blood and the number of cells recovered in the individual harvests. Conclusion: The HyCEAD assay provides adequate sensitivity to simultaneously profile expression levels of more than 100 genes in small numbers of CTCs directly from the lysates of Parsortix harvests. Expression profiling is limited to genes expressed at much higher levels in CTCs than in normal nucleated blood cells. Citation Format: David F. Englert, Mariya Kolesnikova, Nishat Zaman, Arianna Hustler, Gabrielle Wishart, Daniel J. O'Shannessy. Multiplex gene expression using the HyCEAD assay in CTCs isolated with the Parsortix™ system [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2019; 2019 Mar 29-Apr 3; Atlanta, GA. Philadelphia (PA): AACR; Cancer Res 2019;79(13 Suppl):Abstract nr 1375.

Wall enhancement of intracranial saccular and fusiform aneurysms may differ in intensity and extension: a pilot study using 7-T high-resolution black-blood MRI.

To evaluate and compare wall enhancement patterns in saccular and fusiform intracranial aneurysms using high-resolution black-blood MRI at 7T. Thirty-one patients with 32 unruptured intracranial aneurysms (21 saccular and 11 fusiform) underwent 7-T black-blood MRI. Aneurysm wall enhancement (AWE) was categorized as follows: no wall enhancement (NWE), focal wall enhancement (FWE), and uniform wall enhancement (UWE). The degree of enhancement was scored as follows: 0 (no enhancement), 1 (signal intensity (SI) of the aneurysm wall less than that of the pituitary infundibulum), and 2 (equal to that of the pituitary infundibulum). The chi-squared test was used to compare the AWE pattern and degree between saccular and fusiform aneurysms. In saccular aneurysms, 12/21 (57%) enhanced. Of these, 9 showed FWE (5 grade 1 and 4 grade 2), and 3 showed UWE (2 grade 1 and 1 grade 2). In fusiform aneurysms, 11/11 (100%) enhanced. Of these, 1 showed FWE and 10 showed UWE. All fusiform aneurysms had grade-2 enhancement. Fusiform aneurysms had more extensive and higher SI AWE than saccular aneurysms (p < 0.01) despite having a similar size (6.9 ± 3.0mm vs. 8.0 ± 2.9, p = 0.23). For saccular aneurysm, larger aneurysm size was correlated with higher degree of enhancement with Pearson's r = 0.64 (p = 0.002). Intracranial fusiform aneurysms had enhancement of higher SI and that covered a more extensive area than saccular aneurysms, which might indicate differences in vessel wall pathology. • Intracranial aneurysm wall enhancement can be reliably characterized by 7-T black-blood MRI. • AWE in intracranial fusiform aneurysms presents over a larger surface area and with greater signal intensity as compared with that in saccular aneurysms, which might indicate differences in pathology. • Stronger signal intensity of AWE correlates with the aneurysm size in saccular aneurysms.

Enhancing the Sensitivity of Lateral Flow Immunoassay by Centrifugation-Assisted Flow Control.

Lateral flow immunoassay (LFIA) is widely used but is limited by its sensitivity. In this study, a novel centrifugation-assisted lateral flow immunoassay (CLFIA) was proposed that had enhanced sensitivity compared to traditional LFIA based on test strips. For CLFIA, a vaulted piece of nitrocellulose membrane was prepared and inserted into a centrifugal disc. Powered by the centrifugal force, the sample volume on the disc was not limited and the flow rate of the reaction fluid was steady and adjustable at different rotation speeds. It was found that lower rotation speeds and larger sample volumes resulted in greater signal intensity in the nitrocellulose membrane as well as higher sensitivity, indicating that the actively controlled flow on the disc allowed for sensitivity enhancement of CLFIA. To operate CLFIA on the centrifugal disc, a portable and cost-effective operating device was constructed to rotate the disc with a stepper motor and collect the results with a smartphone. The proposed method was successfully applied to detect prostate specific antigen (PSA) in human serum. Standard curves were established for CLFIA and LFIA, and both had correlation coefficients of up to 0.99. Under optimal conditions (1500 rpm rotation speed, 120 μL sample volume), the detection limit of CLFIA reached 0.067 ng/mL, showing a 6.2-fold improvement in sensitivity compared to that of LFIA. With clinical serum samples, a good correlation was observed between PSA concentrations measured by CLFIA and by a bulky commercial instrument in hospital. In summary, this portable, cost-effective, and easy-to-use system holds great promise for biomarker detection with enhanced sensitivity compared to traditional LFIA.

The use of a binary chelate formulation: Could gadolinium based linear contrast agents be rescued by the addition of zinc selective chelates?

Tissue and bone retention of gadolinium based contrast agents (GBCAs) has become a clinical concern because of the potential short and long term toxic effects of free gadolinium. This is a critical problem for most open-chain agents that more readily transmetallate in vivo, in comparison to macrocyclic compounds. Gadolinium diethylene tri-aminepentaacetic acid bis-glucosamide (Gd-DTPA-BIGA) is an experimental, open-chain contrast agent which has a significantly increased relaxivity coefficient in comparison to other GBCAs. This results in greater signal intensity and improved contrast enhancement. These superior imaging qualities initiated a search for a solution to the transmetallation of this agent. Plasma zinc is a well-known GBCA transmettalation agent. Since the base chelate of Gadodiamide (Gd-DPTA-Bis-Methylamide or Omniscan), DTPA-Bis-Methylamide (DTPA-BMA), readily transmettalates with and binds serum zinc, we hypothesized that a plasma “zinc sink,” may significantly reduce transmetallation of linear agents. 5% DTPA-BMA was added to a formulation of Gd-DTPA-BIGA, which was tested against the original formulation of Gd-DTPA-BIGA with 0.2% of the base chelate DTPA-BIGA. These formulations, including gadodiamide, were labeled with 153GdCl3 followed by infusion into cohorts of Sprague Dawley rats which were sacrificed at 1, 30 and 60 days. Internal organs were harvested, along with blood, skin and femur, and analyzed for residual gadolinium. A subset of tissues were also interrogated with ICP-MS. Labeled Gadodiamide and saline where used as controls.Conclusion: The addition of 5% DTPA-BMA, as a zinc binding agent, reduced the transmetallation of the linear agent Gd-DTPA-BIGA, in comparison to its original formulation supplemented with 0.2% BIGA. This result indicates that supplementing linear GBCAs with ancillary chelates may hold promise for reducing, or eliminating the biological archiving of gadolinium in tissues. In addition, this paper provides valuable animal data on the long term retention of gadolinium from linear based contrast agents.

Establishment of a Charge Reversal Derivatization Strategy to Improve the Ionization Efficiency of Limaprost and Investigation of the Fragmentation Patterns of Limaprost Derivatives Via Exclusive Neutral Loss and Survival Yield Method.

Sensitivity is generally an issue in bioassays of prostaglandins and their synthetic analogs due to their extremely low concentration in vivo. To improve the ionization efficiency of limaprost, an oral prostaglandin E1 (PGE1) synthetic analog, we investigated a charge reversal derivatization strategy in electrospray ionization mass spectrometry (ESI-MS). We established that the cholamine derivative exhibits much greater signal intensity in the positive-ion mode compared with limaprost in the negative ion mode. Collision-induced dissociation (CID) involved exclusive neutral mass loss and positive charge migration to form stable cationic product ions with the positive charge on the limaprost residue rather than on the modifying group. This has the effect of maintaining the efficiency and specificity of multiple reaction monitoring (MRM) and avoiding cross talk. CID fragmentation patterns of other limaprost derivatives allowed us to relate the dissociation tendency of different neutral leaving groups to an internal energy distribution scale based on the survival yield method. Knowledge of the energy involved in the production of stabilized positive ions will potentially assist the selection of suitable derivatization reagents for the analysis of a wide variety of lipid acids. Graphical Abstract ᅟ.

Impact of the Characteristic Impedance of Coaxial Lines on the Sensitivity of a 750-MHz Electronically Tunable EPR Resonator

A 750-MHz electronically tunable resonator was investigated in terms of the sensitivity of electron paramagnetic resonance (EPR) signal detection. The conversion efficiency of the radio-frequency magnetic field was calculated for resonators with 50- and 100-Ω coaxial coupling lines using three-dimensional (3D) microwave field and microwave circuit simulators. Based on the simulation results, two tunable resonators were physically constructed and compared in terms of EPR signal sensitivity using a nitroxyl radical solution. While the resonator with 100-Ω coaxial lines provided 14% greater signal intensity, its signal-to-noise ratio was lower than that of the resonator with 50-Ω lines. To demonstrate the capability of the constructed tunable resonator for EPR imaging experiments, a solution of nitroxyl radical and the leg of a tumor-bearing mouse were visualized.

Randomized, controlled, prospective clinical trial of autologous greater omentum free graft versus autogenous cancellous bone graft in radial and ulnar fractures in miniature breed dogs.

To determine the rate of radiographic healing, complications, vascularization, and bone density after repair of radial and ulnar fractures in dogs <6 kg that were treated with an autogenous cancellous bone graft (BG) or free autologous omentum graft (OG). Prospective, randomized, controlled clinical trial with owners/radiologists blinded to treatment. 25 dogs with naturally occurring traumatic radial/ulnar fractures. Fractures underwent plate fixation with OG or BG. Power Doppler ultrasonographic, computed tomographic (CT), and radiographic examinations of the affected antebrachium were performed preoperatively and every 3 weeks postoperatively until healed. Pressure-sensitive walkway gait analysis and owner and veterinarian assessments were obtained preoperatively (0 weeks) and 3, 6, 9, 12, and 24 weeks postoperatively. Owner/veterinarian assessments improved postoperatively but did not differ significantly between groups. The improvement in peak vertical force/vertical impulse was greater in dogs with OG than in those with BG, beginning 3 weeks postoperatively. Radiographic healing occurred earlier in bones treated with OG (median, 9 weeks) than in those treated with BG (12 weeks). Cortical bone density derived from CT of the distal ulna was higher in bones with BG compared with bones with OG. Signal intensity and the number of vessels in the fracture callus declined over time in both groups, according to results of ultrasonography. However, bones retained more vessels and greater signal intensity when treated with OG compared with treatment with BG, according to multiple views at 6 and 9 weeks postoperatively. Omental grafting was not associated with major complications, and it accelerated bone healing and return to weight bearing in dogs. Omental grafting should be considered as an adjunct to stabilization of antebrachial fractures in toy and small breed dogs.

Laser Ablation with Vacuum Capture for MALDI Mass Spectrometry of Tissue.

We have developed a laser ablation sampling technique for matrix-assisted laser desorption ionization (MALDI) mass spectrometry and tandem mass spectrometry (MS/MS) analyses of in-situ digested tissue proteins. Infrared laser ablation was used to remove biomolecules from tissue sections for collection by vacuum capture and analysis by MALDI. Ablation and transfer of compounds from tissue removes biomolecules from the tissue and allows further analysis of the collected material to facilitate their identification. Laser ablated material was captured in a vacuum aspirated pipette-tip packed with C18 stationary phase and the captured material was dissolved, eluted, and analyzed by MALDI. Rat brain and lung tissue sections 10 μm thick were processed by in-situ trypsin digestion after lipid and salt removal. The tryptic peptides were ablated with a focused mid-infrared laser, vacuum captured, and eluted with an acetonitrile/water mixture. Eluted components were deposited on a MALDI target and mixed with matrix for mass spectrometry analysis. Initial experiments were conducted with peptide and protein standards for evaluation of transfer efficiency: a transfer efficiency of 16% was obtained using seven different standards. Laser ablation vacuum capture was applied to freshly digested tissue sections and compared with sections processed with conventional MALDI imaging. A greater signal intensity and lower background was observed in comparison with the conventional MALDI analysis. Tandem time-of-flight MALDI mass spectrometry was used for compound identification in the tissue.

Long-Term Response to Cholinesterase Inhibitor Treatment Is Related to Functional MRI Response in Alzheimer's Disease

Background: Treatment of Alzheimer's disease (AD) with cholinesterase inhibitors (ChEI) enhances cholinergic activity and alleviates clinical symptoms. However, there is variation in the clinical response as well as system level changes revealed by functional MRI (fMRI) studies. Methods: We investigated 18 newly diagnosed mild AD patients with fMRI using a face recognition task after a single oral dose of rivastigmine, a single dose of placebo and 1-month treatment with rivastigmine. The clinical follow-up took place at 6 and 12 months. Results: MMSE score difference between baseline and the follow-ups showed a positive correlation with fMRI activation difference between treatment and placebo in the right prefrontal cortex. A negative correlation was found for the left prefrontal cortex and the left fusiform gyrus. In addition, greater signal intensity in the right versus the left fusiform gyrus predicted a response to ChEI with increasing MMSE scores during the follow-up with 77.8% sensitivity and 77.8% specificity. Conclusions: The increased fMRI activation by cholinergic stimulation in brain areas associated with the processing of the visual task reveals still functioning brain networks and a subsequent positive effect of ChEI on cognition. Thus, fMRI may be useful for identifying AD patients most likely to respond to treatment with ChEI.

A Comparison of Alternating Current and Direct Current Electrospray Ionization for Mass Spectrometry

A series of studies comparing the performance of alternating current electrospray ionization (AC ESI) mass spectrometry (MS) and direct current electrospray ionization (DC ESI) MS have been conducted, exploring the absolute signal intensity and signal-to-background ratios produced by both methods using caffeine and a model peptide as targets. Because the high-voltage AC signal was more susceptible to generating gas discharges, the operating voltage range of AC ESI was significantly smaller than that for DC ESI, such that the absolute signal intensities produced by DC ESI at peak voltages were one to two orders of magnitude greater than those for AC ESI. Using an electronegative nebulizing gas, sulfur hexafluoride (SF6), instead of nitrogen (N2) increased the operating range of AC ESI by ~50%, but did not appreciably improve signal intensities. While DC ESI generated far greater signal intensities, both ionization methods produced comparable signal-to-background noise, with AC ESI spectra appearing qualitatively cleaner. A quantitative calibration analysis was performed for two analytes, caffeine and the peptide MRFA. AC ESI utilizing SF6 outperforms all other techniques for the detection of MRFA, producing chromatographic limits of detection nearly one order of magnitude lower than that of DC ESI utilizing N2, and one-half that of DC ESI utilizing SF6. However, DC ESI outperforms AC ESI for the analysis of caffeine, indicating that improvements in spectral quality may benefit certain compounds or classes of compounds, on an individual basis.

Applicability of 3T Body MRI in Assessment of Nonfocal Bone Marrow Involvement of Hematopoietic Neoplasia in Dogs

The utility of whole body magnetic resonance imaging (MRI) in detecting bone marrow infiltration in dogs with cancer has not been investigated. To assess the feasibility of 3T body MRI for bone marrow assessment in dogs with hematopoietic neoplasia. Seven dogs with B-cell lymphoma, 3 dogs with myelodysplastic syndrome (MDS), and 2 clinically normal dogs. A prospective study of dogs with hematopoetic cancer was conducted using T1W, T2W, In-Phase, Out-of-Phase and STIR pulse sequences of the body excluding the head prior to bone marrow sampling. The relative signal intensity of a midlumbar vertebral body and a midshaft femoral bone marrow was compared by visual and point region of interest analysis to regional skeletal muscle. Similarity of femoral diaphyseal and vertebral body marrow signal intensity to that of skeletal muscle on the Out-of-Phase sequence was useful in distinguishing the 3 dogs with hypercellular marrow because of MDS from the 7 dogs with B-cell lymphoma and from the 2 clinically normal dogs. 1/7 dogs with lymphoma had proven bone marrow involvement but normal cellularity and less than 5% abnormal cells. Unaffected midfemoral marrow had greater signal intensity than skeletal muscle and unaffected vertebral marrow had less signal intensity than skeletal muscle on the Out-of-Phase sequence. 3T, Out-of-Phase MR pulse sequence was useful in distinguishing diffuse bone marrow infiltrate (MDS) from minimally or unaffected marrow using skeletal muscle for signal intensity comparison on whole body MRI.

Extraction of social information from gait in schizophrenia.

The human face and body are rich sources of socio-emotional cues. Accurate recognition of these cues is central to adaptive social functioning. Past studies indicate that individuals with schizophrenia (SZ) show deficits in the perception of emotion from facial cues but the contribution of bodily cues to social perception in schizophrenia is undetermined. The present study examined the detection of social cues from human gait patterns presented by computer-generated volumetric walking figures. A total of 22 SZ and 20 age-matched healthy control participants (CO) viewed 1 s movies of a 'digital' walker's gait and subsequently made a forced-choice decision on the emotional state (angry or happy) or the gender of the walker presented at three intensity levels. Overall sensitivity to the social cues and bias were computed. For SZ, symptom severity was assessed. SZ were less sensitive than CO on both emotion and gender discrimination, regardless of intensity. While impaired overall, greater signal intensity did improve performance of SZ. Neither group differed in their response bias in either condition. The discrimination sensitivity of SZ was unrelated to their social functioning or symptoms but a bias toward perceiving gait as happy was associated with better social functioning. These results suggest that SZ are impaired in extracting social information from gait but SZ benefited from increased signal intensity of social cues. Inaccurate perception of social cues in others may hinder adequate preparation for social interactions.

Distinctive lipid profiles of human breast cancer and adjacent normal tissues by desorption electrospray ionization mass spectrometry imaging.

1132 Background: Routine intra-operative distinction between normal breast tissue and tumor is currently not possible in breast conserving surgery (BCS). This limitation affects the success of surgery, resulting in up to 40% requiring more than one operative procedure. Desorption electrospray ionization mass spectrometry (DESI MS) has been successfully used to discriminate between normal and cancerous human tissues from anatomical sites such as the liver and brain. The aim of this proof of concept study was to determine the feasibility of using DESI MS imaging for tissue identification and differentiation of breast cancer versus normal tissue. Methods: DESI MS imaging was carried out on 14 human invasive breast cancer samples. Breast cancer and adjacent normal paired human tissue sections (margin of tumor, 2cm and 5 cm from tumor) from 14 patients undergoing mastectomy were flash frozen in liquid nitrogen, sectioned, and thaw mounted to glass slides. All samples were imaged using DESI MS at 200 μm imaging resolution. DESI MS images were overlaid and compared with hematoxylin and eosin (H&amp;E) images of the same sections. Results: Discrimination between cancer and adjacent normal tissue was achieved on the basis of the spatial distribution and varying intensities of particular fatty acids and lipid species. Several fatty acids such as oleic acid (m/z 281) and arachidonic acid (m/z 303) displayed much greater signal intensities in the cancer specimen compared to low or undetectable intensities in normal tissue. The cancer margins delineated by the DESI MS images of these molecules were consistent with H and E images of the tumor edge. Cancerous tissue was distinguished from normal tissue based on the qualitative assessment of molecular signatures and the distinction was in agreement with expert histopathology evaluation in 85% of samples. Conclusions: Our findings offer proof of concept that examination and classification of breast normal and cancer tissue by mass spectrometry imaging is highly accurate. The results are encouraging for development of a MS-based method that could be utilized intra-operatively for rapid detection of residual cancer tissue in the lumpectomy bed in BCS.