Proton resonance frequency chemical shift thermometry: experimental design and validation toward high-resolution noninvasive temperature monitoring and in vivo experience in a nonhuman primate model of acute ischemic stroke

BACKGROUND AND PURPOSE

Applications for noninvasive biologic temperature monitoring are widespread in biomedicine and of particular interest in the context of brain temperature regulation, where traditionally costly and invasive monitoring schemes limit their applicability in many settings. Brain thermal regulation, therefore, remains controversial, motivating the development of noninvasive approaches such as temperature-sensitive nuclear MR phenomena. The purpose of this work was to compare the utility of competing approaches to MR thermometry by using proton resonance frequency chemical shift. We tested 3 methodologies, hypothesizing the feasibility of a fast and accurate approach to chemical shift thermometry, in a phantom study at 3T.

MATERIALS AND METHODS

A conventional, paired approach (difference [DIFF]-1), an accelerated single-scan approach (DIFF-2), and a new, further accelerated strategy (DIFF-3) were tested. Phantom temperatures were modulated during real-time fiber optic temperature monitoring, with MR thermometry derived simultaneously from temperature-sensitive changes in the water proton chemical shift (∼0.01 ppm/°C). MR thermometry was subsequently performed in a series of in vivo nonhuman primate experiments under physiologic and ischemic conditions, testing its reproducibility and overall performance.

RESULTS

Chemical shift thermometry demonstrated excellent agreement with phantom temperatures for all 3 approaches (DIFF-1: linear regression R(2) = 0.994; P < .001; acquisition time = 4 minutes 40 seconds; DIFF-2: R(2) = 0.996; P < .001; acquisition time = 4 minutes; DIFF-3: R(2) = 0.998; P < .001; acquisition time = 40 seconds).

CONCLUSIONS

These findings confirm the comparability in performance of 3 competing approaches to MR thermometry and present in vivo applications under physiologic and ischemic conditions in a primate stroke model.

Dual imaging-guided photothermal/photodynamic therapy using micelles

We report a type of photosensitizer (PS)-loaded micelles integrating cyanine dye as potential theranostic micelles for precise anatomical tumor localization via dual photoacoustic (PA)/near-infrared fluorescent (NIRF) imaging modalities, and simultaneously superior cancer therapy via sequential synergistic photothermal therapy (PTT)/photodynamic therapy (PDT). The micelles exhibit enhanced photostability, cell internalization and tumor accumulation. The dual NIRF/PA imaging modalities of the micelles cause the high imaging contrast and spatial resolution of tumors, which provide precise anatomical localization of the tumor and its inner vasculature for guiding PTT/PDT treatments. Moreover, the micelles can generate severe photothermal damage on cancer cells and destabilization of the lysosomes upon PTT photoirradiation, which subsequently facilitate synergistic photodynamic injury via PS under PDT treatment. The sequential treatments of PTT/PDT trigger the enhanced cytoplasmic delivery of PS, which contributes to the synergistic anticancer efficacy of PS. Our strategy provides a dual-modal cancer imaging with high imaging contrast and spatial resolution, and subsequent therapeutic synergy of PTT/PDT for potential multimodal theranostic application.

Impact of psm-mec in the mobile genetic element on the clinical characteristics and outcome of SCCmec-II methicillin-resistant Staphylococcus aureus bacteraemia in Japan

Over-expression of alpha-phenol-soluble modulins (PSMs) results in high virulence of community-associated methicillin-resistant Staphylococcus aureus (MRSA). The psm-mec gene, located in the mobile genetic element SCCmec-II, suppresses PSMαs production. Fifty-two patients with MRSA bacteraemia were enrolled. MRSA isolates were evaluated with regard to the psm-mec gene sequence, bacterial virulence, and the minimum inhibitory concentration (MIC) of vancomycin and teicoplanin. Fifty-one MRSA isolates were classified as SCCmec-II, and 10 had one point mutation in the psm-mec promoter. We compared clinical characteristics and outcomes between mutant MRSA and wild-type MRSA. Production of PSMα3 in mutant MRSA was significantly increased, but biofilm formation was suppressed. Wild-type MRSA caused more catheter-related bloodstream infections (30/41 vs. 3/10, p 0.0028), whereas mutant MRSA formed more deep abscesses (4/10 vs. 3/41, p 0.035). Bacteraemia caused by mutant MRSA was associated with reduced 30-day mortality (1/10 vs. 13/41, p 0.25), although this difference was not significant. The MIC90 of teicoplanin was higher for wild-type MRSA (1.5 mg/L vs. 1 mg/L), but the MIC of vancomycin was not different between the two groups. The 30-day mortality of MRSA with a high MIC of teicoplanin (≥1.5 mg/L) was higher than that of strains with a lower MIC (≤0.75 mg/L) (6/10 vs. 6/33, p 0.017). Mutation of the psm-mec promoter contributes to virulence of SCCmec-II MRSA, and the product of psm-mec may determine the clinical characteristics of bacteraemia caused by SCCmec-II MRSA, but it does not affect mortality.

Highly efficient hierarchical micelles integrating photothermal therapy and singlet oxygen-synergized chemotherapy for cancer eradication

It is highly desirable to develop theranostic nanoparticles for achieving cancer imaging with enhanced contrast and simultaneously multimodal synergistic therapy. Herein, we report a theranostic micelle system hierarchically assembling cyanine dye (indocyanine green) and chemotherapeutic compound (doxorubicin) (I/D-Micelles) as a novel theranostic platform with high drug loading, good stability and enhanced cellular uptake via clathrin-mediated endocytosis. I/D-Micelles exhibit the multiple functionalities including near-infrared fluorescence (NIRF), hyperthermia and intracellular singlet oxygen from indocyanine green, and simultaneous cytotoxicity from doxorubicin. Upon photoirradiation, I/D-Micelles can induce NIRF imaging, acute photothermal therapy via hyperthermia and simultaneous synergistic chemotherapy via singlet oxygen-triggered disruption of lysosomal membranes, eventually leading to enhanced NIRF imaging and superior tumor eradication without any re-growth. Our results suggest that the hierarchical micelles can act as a superior theranostic platform for cancer imaging and multimodal synergistic therapy.

Human infection with avian influenza A(H7N9) virus re-emerges in China in winter 2013

Through a national surveillance system for unexplained pneumonia, a severe case of influenza A(H7N9) in a man in his mid-30s was identified in Zhejiang Province, China on 14 October 2013. Epidemiological and clinical findings were consistent with the patterns reported during the outbreak in spring 2013, and laboratory findings showed that the virus had 99.6% identity with earlier H7N9 viruses identified in humans in the spring except for five mutations in the NA gene.

Targeted delivery of siRNA-generating DNA nanocassettes using multifunctional nanoparticles

Molecular therapy using a small interfering RNA (siRNA) has shown promise in the development of novel therapeutics. Various formulations have been used for in vivo delivery of siRNAs. However, the stability of short double-stranded RNA molecules in the blood and efficiency of siRNA delivery into target organs or tissues following systemic administration have been the major issues that limit applications of siRNA in human patients. In this study, multifunctional siRNA delivery nanoparticles are developed that combine imaging capability of nanoparticles with urokinase plasminogen activator receptor-targeted delivery of siRNA expressing DNA nanocassettes. This theranostic nanoparticle platform consists of a nanoparticle conjugated with targeting ligands and double-stranded DNA nanocassettes containing a U6 promoter and a shRNA gene for in vivo siRNA expression. Targeted delivery and gene silencing efficiency of firefly luciferase siRNA nanogenerators are demonstrated in tumor cells and in animal tumor models. Delivery of survivin siRNA expressing nanocassettes into tumor cells induces apoptotic cell death and sensitizes cells to chemotherapy drugs. The ability of expression of siRNAs from multiple nanocassettes conjugated to a single nanoparticle following receptor-mediated internalization should enhance the therapeutic effect of the siRNA-mediated cancer therapy.

Observation of two new N* resonances in the decay ψ(3686)→ppπ0

Based on 106×10(6)ψ(3686) events collected with the BESIII detector at the BEPCII facility, a partial wave analysis of ψ(3686)→ppπ0 is performed. The branching fraction of this channel has been determined to be B(ψ(3686)→ppπ0)=(1.65±0.03±0.15)×10(-4). In this decay, 7 N* intermediate resonances are observed. Among these, two new resonances, N(2300) and N(2570) are significant, one 1/2+ resonance with a mass of 2300(-30-0)(+40+109)  MeV/c2 and width of 340(-30-58)(+30+110)  MeV/c2, and one 5/2- resonance with a mass of 2570(-10-10)(+19+34)  MeV/c2 and width of 250(-24-21)(+14+69)  MeV/c2. For the remaining 5 N* intermediate resonances [N(1440), N(1520), N(1535), N(1650) and N(1720)], the analysis yields mass and width values that are consistent with those from established resonances.

Late onset systemic lupus erythematosus with severe hypercalcaemia

We report a case of a 76-year old female presenting with symptomatic severe hypercalcaemia, and subsequently diagnosed with late onset SLE due to the presence of anaemia, leucopenia, antibodies of antinuclear (ANA), anti-dsDNA, and also kidney impairment. Serum levels of FGF23 and intact-parathyroid hormone (iPTH) were low in this patient. Serum calcium, FGF23 and iPTH levels responded to steroids, which occurred simultaneously with disease activity. On follow-up, the faster increase in FGF23 than in parathyroid hormone suggested that FGF23 might be involved in the pathogenesis of hypercalcaemia in SLE.

Evidence for the direct two-photon transition from ψ(3686) to J/ψ

The two-photon transition ψ(3686)→γγJ/ψ is studied in a sample of 1.06×10(8) ψ(3686) decays collected by the BESIII detector. The branching fraction is measured to be (3.1±0.6(stat)(-1.0)(+0.8)(syst))×10(-4) using J/ψ→e(+)e(-) and J/ψ→μ(+)μ(-) decays, and its upper limit is estimated to be 4.5×10(-4) at the 90% confidence level. This work represents the first measurement of a two-photon transition among charmonium states. The orientation of the ψ(3686) decay plane and the J/ψ polarization in this decay are also studied. In addition, the product branching fractions of sequential E1 transitions ψ(3686)→γχ(cJ) and χ(cJ)→γJ/ψ(J=0,1,2) are reported.

First observation of the M1 transition ψ(3686)→γη(c)(2S)

Using a sample of 106×10(6) ψ(3686) events collected with the BESIII detector at the BEPCII storage ring, we have made the first measurement of the M1 transition between the radially excited charmonium S-wave spin-triplet and the radially excited S-wave spin-singlet states: ψ(3686)→γη(c)(2S). Analyses of the processes ψ(3686)→γη(c)(2S) with η(c)(2S)→K(S)(0)K(±)π(∓) and K(+)K(-)π(0) give an η(c)(2S) signal with a statistical significance of greater than 10 standard deviations under a wide range of assumptions about the signal and background properties. The data are used to obtain measurements of the η(c)(2S) mass (M(η(c)(2S))=3637.6±2.9(stat)±1.6(syst) MeV/c(2)), width (Γ(η(c)(2S))=16.9±6.4(stat)±4.8(syst) MeV), and the product branching-fraction (B(ψ(3686)→γη(c)(2S))×B(η(c)(2S)→KKπ)=(1.30±0.20(stat)±0.30(syst))×10(-5)). Combining our result with a BABAR measurement of B(η(c)(2S)→KKπ), we find the branching fraction of the M1 transition to be B(ψ(3686)→γη(c)(2S))=(6.8±1.1(stat)±4.5(syst))×10(-4).

Measurements of the mass and width of the η(c) using the decay ψ(3686)→γη(c)

The mass and width of the lowest-lying S-wave spin singlet charmonium state, the η(c), are measured using a data sample of 1.06×10(8) ψ(3686) decays collected with the BESIII detector at the BEPCII storage ring. We use a model that incorporates full interference between the signal reaction, ψ(3686)→γη(c), and a nonresonant radiative background to describe the line shape of the η(c) successfully. We measure the η(c) mass to be 2984.3±0.6±0.6 MeV/c(2) and the total width to be 32.0±1.2±1.0 MeV, where the first errors are statistical and the second are systematic.

First observation of η(1405) decays into f(0)(980)π0

The decays J/ψ → γ π+ π- π0 and J/ψ → γ π0 π0 π0 are analyzed using a sample of 225×10(6) J/ψ events collected with the BESIII detector. The decay of η(1405) → f(0)(980)π0 with a large isospin violation is observed for the first time. The width of the f(0)(980) observed in the dipion mass spectra is anomalously narrower than the world average. Decay rates for three-pion decays of the η' are also measured precisely.

Spin-parity analysis of pp¯ mass threshold structure in J/ψ and ψ(3686) radiative decays

A partial wave analysis of the pp¯ mass-threshold enhancement in the reaction J/ψ→γpp¯ is used to determine its J(PC) quantum numbers to be 0(-+), its peak mass to be below threshold at M=1832(-5)(+19)(stat)(-17)(+18)(syst)±19(model) MeV/c(2), and its total width to be Γ<76 MeV/c(2) at the 90% C.L. The product of branching ratios is measured to be BR[J/ψ→γX(pp¯)]BR[X(pp¯)→pp¯]=[9.0(-1.1)(+0.4)(stat)(-5.0)(+1.5)(syst)±2.3(model)]×10(-5). A similar analysis performed on ψ(3686)→γpp¯ decays shows, for the first time, the presence of a corresponding enhancement with a production rate relative to that for J/ψ decays of R=[5.08(-0.45)(+0.71)(stat)(-3.58)(+0.67)(syst)±0.12(model)]%.

ηπ+ π- resonant structure around 1.8 GeV/c(2) and η(1405) in J/ψ → ωηπ+ π-

We present results of a study of the decay J/ψ → ωηπ+ π- using a sample of (225.2 ± 2.8) × 10(6) J/ψ events collected by the BESIII detector, and report the observation of a new process J/ψ → ωX(1870) with a statistical significance of 7.2σ, in which X(1870) decays to a(0)(±)(980)π±. Fitting to ηπ+ π- mass spectrum yields a mass M = 1877.3 ± 6.3(stat)(-7.4)(+3.4)(syst) MeV/c(2), a width Γ = 57 ± 12(stat)(-4)(+19)(syst) MeV/c(2), and a product branching fraction B(J/ψ → ωX) × B(X→a(0)(±)(980)π±) × B(a(0) (±)(980) → ηπ±) = [1.50 ± 0.26(stat)(-0.36)(+0.72) (syst)] × 10(-4). Signals for J/ψ → ωf(1)(1285) and J/ψ → ω η(1405) are also clearly observed and measured.

Observation of χ(c1) decays into vector meson pairs φφ, ωω, and ωφ

Using (106±4)×10⁻⁶ ψ(3686) events accumulated with the BESIII detector at the BEPCII e⁺e⁻ collider, we present the first measurement of decays of χ(c1) to vector meson pairs φφ, ωω, and ωφ. The branching fractions are measured to be (4.4±0.3±0.5)×10⁻⁴, (6.0±0.3±0.7)×10⁻⁴, and (2.2±0.6±0.2)×10⁻⁵, for χ(c1)→φφ, ωω, and ωφ, respectively, which indicates that the hadron helicity selection rule is significantly violated in χ(cJ) decays. In addition, the measurement of χ(cJ)→ωφ provides the first indication of the rate of doubly OZI-suppressed χ(cJ) decay. Finally, we present improved measurements for the branching fractions of χ(c0) and χ(c2) to vector meson pairs.

Confirmation of the X(1835) and observation of the resonances X(2120) and X(2370) in J/ψ→γπ+π-η'

With a sample of (225.2±2.8)×10(6) J/ψ events registered in the BESIII detector, J/ψ→γπ(+)π(-)η(') is studied using two η(') decay modes: η(')→π(+)π(-)η and η(')→γρ(0). The X(1835), which was previously observed by BESII, is confirmed with a statistical significance that is larger than 20σ. In addition, in the π(+)π(-)η(') invariant-mass spectrum, the X(2120) and the X(2370), are observed with statistical significances larger than 7.2σ and 6.4σ, respectively. For the X(1835), the angular distribution of the radiative photon is consistent with expectations for a pseudoscalar.

Evidence for ψ' decays into γπ0 and γη

The decays ψ'→γπ(0), γη and γη' are studied using data collected with the BESIII detector at the BEPCII e(+)e(-) collider. The processes ψ'→γπ(0) and ψ'→γη are observed for the first time with signal significances of 4.6σ and 4.3σ, respectively. The branching fractions are determined to be B(ψ'→γπ(0))=(1.58±0.40±0.13)×10(-6), B(ψ'→γη)=(1.38±0.48±0.09)×10(-6), and B(ψ'→γη')=(126±3±8)×10(-6), where the first errors are statistical and the second ones systematic.

Effects of a Cannabinoid Receptor 2 Selective Antagonist on the Inflammatory Reaction to Titanium Particles In Vivo and In Vitro

Wear particle-induced inflammation is a major factor contributing to aseptic loosening in peri-prosthetic tissue. The effects of cannabinoid receptor 2 (CB2) on wear particle-induced inflammation remain unclear. Reverse transcription–polymerase chain reaction and enzyme-linked immunosorbent assay were used to assess the effects of a CB2-selective antagonist, AM630, on regulation of the inflammatory reaction and production of pro-inflammatory cytokines in response to in vitro and in vivo stimulation with titanium particles. In vitro studies, in a model for pre-osteoclast-like cells, demonstrated that AM630 inactivation of CB2 profoundly inhibited interleukin (IL)-1β and tumour necrosis factor (TNF)-α production by RAW264.7 cells stimulated with titanium particles. In vivo findings in a murine air-pouch model of titanium-induced inflammatory osteolysis indicated that AM630 reduced titanium-induced tissue inflammation, seen as a reduction in pouch membrane thickness, inflammatory infiltration and levels of the pro-inflammatory cytokines IL-1β and TNF-α. Thus, inactivation of CB2 by AM630 inhibited the titanium particle-induced inflammatory reaction by reducing pro-inflammatory cytokines in vitro and in vivo.

A 6-bp deletion in the TYRP1 gene causes the brown colouration phenotype in Chinese indigenous pigs

Brown coat colour has been described in Chinese-Tibetan, Kele, and Dahe pigs. Here, we report the identification of a causal mutation underlying the brown colouration. We performed a genome-wide association study (GWAS) on Tibetan and Kele pigs, and found that brown colours in Chinese breeds are controlled by a single locus on pig chromosome 1. By using a haplotype-sharing analysis, we refined the critical region to a 1.5-Mb interval that encompasses only one pigmentation gene: tyrosinase-related protein 1 (TYRP1). Mutation screens of sequence variants in the coding region of TYRP1 revealed a strong candidate causative mutation (c.1484_1489del). The protein-altering deletion showed complete association with the brown colouration across Chinese-Tibetan, Kele, and Dahe breeds by occurring exclusively in brown pigs (n=121) and lacking in all non-brown-coated pigs (n=745) from 27 different breeds. The findings provide the compelling evidence that brown colours in Chinese indigenous pigs are caused by the same ancestral mutation in TYRP1. To our knowledge, this study gives the first description of GWAS identifying causal mutation for a monogenic trait in the domestic pig.

Genetic diversity and origin of Gayal and cattle in Yunnan revealed by mtDNA control region and SRY gene sequence variation

There are hump, humpless cattle and gayal distributed in Yunnan province, south-west China, but their genetic background remains unclear. To determine the origin and genetic diversity of Yunnan gayal and cattle (Diqing, Nujiang and Wenshan cattle), we analysed mtDNA control region sequences of 71 samples and SRY gene sequences of 39 samples, together with the available sequences in GenBank. The neighbour-joining phylogeny and the reduced median network analysis showed that Yunnan gayal originated from the hybridization between male Bos frontalis and female Bos taurus or Bos indicus, and that Yunnan cattle mostly originated from B. indicus, also containing some hybrids of male B. indicus and female B. taurus. The phylogenetic pattern of Yunnan cattle was consistent with the recently described cattle matrilineal pool from China and indicated more contribution to the Yunnan cattle from B. indicus than from B. taurus.

Alterations in cortical thickness and white matter integrity in mild cognitive impairment measured by whole-brain cortical thickness mapping and diffusion tensor imaging

BACKGROUND AND PURPOSE

Mild cognitive impairment (MCI) is a risk factor for Alzheimer disease and can be difficult to diagnose because of the subtlety of symptoms. This study attempted to examine gray matter (GM) and white matter (WM) changes with cortical thickness analysis and diffusion tensor imaging (DTI) in patients with MCI and demographically matched comparison subjects to test these measurements as possible imaging markers for diagnosis.

MATERIALS AND METHODS

Subjects with amnestic MCI (n = 10; age, 72.2 +/- 7.1 years) and normal cognition (n = 10; age, 70.1 +/- 7.7 years) underwent DTI and T1-weighted MR imaging at 3T. Fractional anisotropy (FA), apparent diffusion coefficient (ADC), and cortical thickness were measured and compared between the MCI and control groups. We evaluated the diagnostic accuracy of 2 methods, either in combination or separately, using binary logistic regression and nonparametric statistical analyses for sensitivity, specificity, and accuracy.

RESULTS

Decreased FA and increased ADC in WM regions of the frontal and temporal lobes and corpus callosum (CC) were observed in patients with MCI. Cortical thickness was decreased in GM regions of the frontal, temporal, and parietal lobes in patients with MCI. Changes in WM and cortical thickness seemed to be more pronounced in the left hemisphere compared with the right hemisphere. Furthermore, the combination of cortical thickness and DTI measurements in the left temporal areas improved the accuracy of differentiating MCI patients from control subjects compared with either measure alone.

CONCLUSIONS

DTI and cortical thickness analyses may both serve as imaging markers to differentiate MCI from normal aging. Combined use of these 2 methods may improve the accuracy of MCI diagnosis.

Multifunctional and multiplexed nanoparticles for molecular imaging and treatment of breast cancer

Abstract #6003

Multifunctional nanoparticles with the ability to target tumors, provide molecular imaging and to deliver therapeutic agents hold great promise for improving the survival of cancer patients. We have developed multifunctional nanoparticles targeted to cellular receptors that are highly expressed in breast cancer and tumor stromal cells. Fluorescent quantum dot (QD) or magnetic iron oxide (IO) nanoparticles are conjugated to either the amino-terminal fragment (ATF) of urokinase plasminogen activator (uPA) or to a single chain antibody against the epidermal growth factor receptor (ScFvEGFR), resulting in uPAR or EGFR targeted nanoparticles. Since the binding of ATF peptides or ScFvEGFR to their receptors results in blocking receptor function and internalization of the receptor-ligand complex, these targeted imaging probes can also inhibit tumor growth and deliver drugs. Using near infrared fluorescence (NIR) dye-labeled targeting peptides, we demonstrate specificity of these targeting ligands in an orthotopic human breast cancer model in nude mice. We found that tail vein injection of a mixture of Cy5.5 dye-ATF and IRDye 800-ScFvEGFR peptides leads to the selective accumulation of both probes in human breast cancer xenografts and NIR optical imaging of the tumors in the mammary fat pad of nude mice (Fig. A).&#x2028; &#x2028; We show that uPAR- and EGFR-targeted nanoprobes display different patterns of intratumoral distribution with EGFR probes in the central area and uPAR probes in the peripheral and central regions of the tumor, which may be the results of expressing uPAR in the invasive edge of tumor cells and tumor stromal cells and EGFR only in tumor cells. In vivo optical imaging using ATF-nanoparticles is also demonstrated in human breast cancer xenograft (Fig. B) and in mouse mammary tumor lung metastatic models. Furthermore, magnetic Cy5.5-ATF IO nanoparticles are multimodality imaging probes for both optical and MR tumor imaging. Since magnetic IO nanoparticles are biodegradable and relatively safe for human use, we have developed a therapeutic imaging nanoparticle by encapsulating doxorubicin into the polymer coating of the nanoparticles and have shown selective delivery of the drug and cytotoxic effect in breast cancer cells in vitro. Results of our study show that multifunctional and multiplexed nanoparticles have great potential for the development of novel tumor imaging and therapeutic approaches.

Citation Information: Cancer Res 2009;69(2 Suppl):Abstract nr 6003.

Lack of association of VEGF promoter polymorphisms with sporadic ALS

The authors tested the association of three vascular endothelial growth factor (VEGF) promoter polymorphisms with sporadic ALS (SALS) to verify the results of a previous study and to investigate their modifier effects on the subphenotypes of SALS in a large family-based and case-control cohort of North American white subjects (N = 1,603). They did not find any association of the VEGF promoter polymorphisms with SALS or its subphenotypes, suggesting that they do not have a direct causal role in ALS.