Detection and Characterization of Sentinel Lymph Node by Ultrasound Molecular Imaging with B7-H3-Targeted Microbubbles in Orthotopic Breast Cancer Model in Mice

PURPOSE

Accurate identification and assessment of sentinel lymph node (SLN) using noninvasive imaging methods can play a vital role in tumor staging, surgical planning, and prognostic evaluation. In this study, we assessed the efficacy of B7-H3-targeted molecular-ultrasound imaging for the early SLN detection, and characterization in a mouse model of orthotopic breast cancer.

PROCEDURES

We established a mouse breast cancer model with lymph node metastasis by injecting MAD-MB 231 cells which were engineered to express firefly luciferase reporter gene into the fat pad of the right 4th mammary gland in female BALB/c nude mice. The sole lymph node (LN) close to the tumor was regarded as the SLN for imaging investigation, which included metastatic and non-metastatic SLNs. The LN in the right 4th mammary gland from normal mice was used as normal control (normal mice LN). The commercially available preclinical streptavidin-coated, perfluorocarbon-containing lipid-shelled microbubbles (VisualSonics, Toronto, Canada) were used to generate B7-H3-targeted microbubbles (MB_B7-H3) and control microbubbles (MB_Control). Then, ultrasound molecular imaging (USMI) was performed using a high-resolution transducer (MS250; center frequency, 21 MHz; Vevo 2100; VisualSonics, Toronto, Canada) after intravenous injection of microbubbles.

RESULTS

The SLN was clearly detected and located under conventional (B-mode) and contrast-enhanced ultrasonography with microbubble injection. The metastatic SLNs showed a markedly higher signal from B7-H3-targeted microbubbles (MB_B7-H3) compared to the non-metastatic SLNs and normal LNs. The metastatic SLN was further confirmed by ex vivo bioluminescence imaging and eventually verified by histological analysis.

CONCLUSIONS

Our findings suggest the potential value of USMI using B7-H3 targeted microbubbles in breast cancer and establish an effective imaging method for the non-invasive detection and characterization of SLN.

Photoacoustic Molecular Imaging for the Identification of Lymph Node Metastasis in Head and Neck Cancer Using an Anti-EGFR Antibody-Dye Conjugate

The presence of lymph node (LN) metastases is an essential prognostic indicator in patients with head and neck squamous cell carcinoma (HNSCC). This study assessed photoacoustic molecular imaging (PAMI) of the antiepidermal growth factor receptor antibody (panitumumab) conjugated to a near-infrared fluorescent dye, IRDye800CW (panitumumab-IRDye800CW; pan800), for the identification of occult metastatic LNs in patients with HNSCC (n = 7). Methods: After in vitro photoacoustic imaging characterization of pan800, PAMI was performed on excised neck specimens from patients infused with pan800 before surgery. Freshly obtained neck specimens were imaged with 3-dimensional, multiwavelength spectroscopic PAMI (wavelengths of 680, 686, 740, 800, 860, 924, and 958 nm). Harvested LNs were then imaged with a closed-field near-infrared fluorescence imager and histologically examined by the pathologist to determine their metastatic status. Results: In total, 53 LNs with a maximum diameter of 10 mm were analyzed with photoacoustic and fluorescence imaging, of which 4 were determined to be metastatic on the final histopathologic report. Photoacoustic signals in the LNs corresponding to accumulated pan800 were spectrally unmixed using a linear least-square-error classification algorithm. The average thresholded photoacoustic signal intensity corresponding to pan800 was 5-fold higher for metastatic LNs than for benign LNs (2.50 ± 1.09 arbitrary units [a.u.] vs. 0.53 ± 0.32 a.u., P < 0.001). Fluorescence imaging showed that metastatic LNs had a 2-fold increase in fluorescence signal compared with benign LNs ex vivo (P < 0.01, 0.068 ± 0.027 a.u. vs. 0.035 ± 0.018 a.u.). Moreover, the ratio of the average of the highest 10% of the photoacoustic signal intensity over the total average, representative of the degree of heterogeneity in the pan800 signal in LNs, showed a significant difference between metastatic LNs and benign LNs (11.6 ± 13.4 vs. 1.8 ± 0.7, P < 0.01) and an area under the receiver-operating-characteristic curve of 0.96 (95% CI, 0.91-1.00). Conclusion: The data indicate that PAMI of IRDye800-labeled tumor-specific antibody may have the potential to identify occult LN metastasis perioperatively in HNSCC patients.

Evaluation of ductal carcinoma in situ grade via triple-modal molecular imaging of B7-H3 expression

Ductal carcinoma in situ (DCIS) will account for 62,930 cases of breast cancer in 2019. DCIS is a pre-invasive lesion which may not progress to invasive carcinoma, yet surgery remains the mainstay treatment. Molecular imaging of a specific marker for DCIS grade for detection and active surveillance are critically needed to reduce potential overtreatment. First, breast cancer marker B7-H3 (CD276) expression was evaluated by immunohistochemical staining in 123 human specimens including benign epithelium (H-score 10.0 ± 8.2) and low (20.8 ± 17.7), intermediate (87.1 ± 69.5), and high (159.1 ± 87.6) grade DCIS, showing a positive association with DCIS nuclear grade (P < 0.001, AUC 0.96). Next, a murine DCIS model was combined with ultrasound molecular imaging of B7-H3 targeted microbubbles to differentiate normal glands from those harboring DCIS (n = 100, FVB/N-Tg(MMTVPyMT)634Mul, AUC 0.89). Finally, photoacoustic and fluorescence molecular imaging with an anti-B7-H3 antibody-indocyanine green conjugate were utilized for DCIS detection (n = 53). Molecular imaging of B7-H3 expression may allow for active surveillance of DCIS.

Efficacy of Affibody-Based Ultrasound Molecular Imaging of Vascular B7-H3 for Breast Cancer Detection

PURPOSE

Human B7-H3 (hB7-H3) is a promising molecular imaging target differentially expressed on the neovasculature of breast cancer and has been validated for preclinical ultrasound (US) imaging with anti-B7-H3-antibody-functionalized microbubbles (MB). However, smaller ligands such as affibodies (ABY) are more suitable for the design of clinical-grade targeted MB.

EXPERIMENTAL DESIGN

Binding of ABY_B7-H3 was confirmed with soluble and cell-surface B7-H3 by flow cytometry. MB were functionalized with ABY_B7-H3 or anti-B7-H3-antibody (Ab_B7-H3). Control and targeted MB were tested for binding to hB7-H3-expressing cells (MS1_hB7-H3) under shear stress conditions. US imaging was performed with MB_ABY-B7-H3 in an orthotopic mouse model of human MDA-MB-231 coimplanted with MS1_hB7-H3 or control MS1_WT cells and a transgenic mouse model of breast cancer development.

RESULTS

ABY_B7-H3 specifically binds to MS1_hB7-H3 and murine-B7-H3-expressing monocytes. MB_ABY-B7-H3 (8.5 ± 1.4 MB/cell) and MB_Ab-B7-H3 (9.8 ± 1.3 MB/cell) showed significantly higher (P < 0.0001) binding to the MS1_hB7-H3 cells compared with control MB_Non-targeted (0.5 ± 0.1 MB/cell) under shear stress conditions. In vivo, MB_ABY-B7-H3 produced significantly higher (P < 0.04) imaging signal in orthotopic tumors coengrafted with MS1_hB7-H3 (8.4 ± 3.3 a.u.) compared with tumors with MS1_WT cells (1.4 ± 1.0 a.u.). In the transgenic mouse tumors, MB_ABY-B7-H3 (9.6 ± 2.0 a.u.) produced higher (P < 0.0002) imaging signal compared with MB_Non-targeted (1.3 ± 0.3 a.u.), whereas MB_ABY-B7-H3 signal in normal mammary glands and tumors with B7-H3 blocking significantly reduced (P < 0.02) imaging signal.

CONCLUSIONS

MB_ABY-B7-H3 enhances B7-H3 molecular signal in breast tumors, improving cancer detection, while offering the advantages of a small size ligand and easier production for clinical imaging.

In Vivo Immunofluorescence Localization for Assessment of Therapeutic and Diagnostic Antibody Biodistribution in Cancer Research

Monoclonal antibodies (mAbs) are important tools in cancer detection, diagnosis, and treatment. They are used to unravel the role of proteins in tumorigenesis, can be directed to cancer biomarkers enabling tumor detection and characterization, and can be used for cancer therapy as mAbs or antibody-drug conjugates to activate immune effector cells, to inhibit signaling pathways, or directly kill cells carrying the specific antigen. Despite clinical advancements in the development and production of novel and highly specific mAbs, diagnostic and therapeutic applications can be impaired by the complexity and heterogeneity of the tumor microenvironment. Thus, for the development of efficient antibody-based therapies and diagnostics, it is crucial to assess the biodistribution and interaction of the antibody-based conjugate with the living tumor microenvironment. Here, we describe In Vivo Immunofluorescence Localization (IVIL) as a new approach to study interactions of antibody-based therapeutics and diagnostics in the in vivo physiological and pathological conditions. In this technique, a therapeutic or diagnostic antigen-specific antibody is intravenously injected in vivo and localized ex vivo with a secondary antibody in isolated tumors. IVIL, therefore, reflects the in vivo biodistribution of antibody-based drugs and targeting agents. Two IVIL applications are described assessing the biodistribution and accessibility of antibody-based contrast agents for molecular imaging of breast cancer. This protocol will allow future users to adapt the IVIL method for their own antibody-based research applications.

Affibody-Indocyanine Green Based Contrast Agent for Photoacoustic and Fluorescence Molecular Imaging of B7-H3 Expression in Breast Cancer

Spectroscopic photoacoustic (sPA) molecular imaging has high potential for identification of exogenous contrast agents targeted to specific markers. Antibody-dye conjugates have recently been used extensively for preclinical sPA and other optical imaging modalities for highly specific molecular imaging of breast cancer. However, antibody-based agents suffer from long circulation times that limit image specificity. Here, the efficacy of a small protein scaffold, the affibody (ABY), conjugated to indocyanine green (ICG), a near-infrared fluorescence dye, as a targeted molecular imaging probe is demonstrated. In particular, B7-H3 (CD276), a cellular receptor expressed in breast cancer, was imaged via sPA and fluorescence molecular imaging to differentiate invasive tumors from normal glands in mice. Administration of ICG conjugated to an ABY specific to B7-H3 (ABYB7-H3-ICG) showed significantly higher signal in mammary tumors compared to normal glands of mice. ABYB7-H3-ICG is a compelling scaffold for molecular sPA imaging for breast cancer detection.

Pharmacokinetics and safety of repeated oral dosing of acetaminophen in adult horses

BACKGROUND

There are no published studies on the pharmacokinetics of acetaminophen at the dosage used clinically (20 mg/kg), nor has the safety of multiple doses in horses been investigated.

OBJECTIVE

Define the pharmacokinetic parameters of oral acetaminophen at 20 mg/kg in adult horses as a single dose, and twice daily for 14 days to assess the safety of multiple dosing.

STUDY DESIGN

Pharmacokinetic study, multiple dose safety study.

METHODS

Eight healthy Thoroughbred geldings were given acetaminophen (20 mg/kg; 500 mg tablets) orally as a single dose followed by doses every 12 h for 14 days. Serial blood samples were collected for determination of plasma acetaminophen concentrations using high performance liquid chromatography with ultraviolet detection. Serum biochemical analysis, gastroscopy and liver biopsy were examined during the safety study.

RESULTS

Following a single dose, mean maximum concentration (C_max ) was 16.61 μg/mL at 1.35 h (T_max ), and drug concentration was below the lower limit of detection in most horses by 24 h. Elimination half-life (T_1/2 ) was 2.78 h. No significant accumulation was noted following multiple doses. Average C_max of acetaminophen following multiple oral dosing was 15.85 μg/mL, with a T_max of 0.99 h and T_1/2 of 4 h. Serum activities of sorbitol dehydrogenase were significantly decreased and total bilirubin concentrations were significantly increased following the last dose. No statistically significant changes were noted in gastroscopy scores.

MAIN LIMITATIONS

Only one dose level (20 mg/kg) was studied, sample size was small and only a single breed and sex was used, with no pretreatment liver biopsies.

CONCLUSION

This study described the pharmacokinetics of acetaminophen following single and multiple 20 mg/kg oral doses in adult horses and demonstrated the safety of acetaminophen with multiple oral dosing over 14 days. The summary is available in Portuguese - see Supporting information.

Ultrasound molecular imaging as a non-invasive companion diagnostic for netrin-1 interference therapy in breast cancer

In ultrasound molecular imaging (USMI), ligand-functionalized microbubbles (MBs) are used to visualize vascular endothelial targets. Netrin-1 is upregulated in 60% of metastatic breast cancers and promotes tumor progression. A novel netrin-1 interference therapy requires the assessment of netrin-1 expression prior to treatment. In this study, we studied netrin-1 as a target for USMI and its potential as a companion diagnostic in breast cancer models. Methods: To verify netrin-1 expression and localization, an in vivo immuno-localization approach was applied, in which anti-netrin-1 antibody was injected into living mice 24 h before tumor collection, and revealed with secondary fluorescent antibody for immunofluorescence analysis. Netrin-1 interactions with the cell surface were studied by flow cytometry. Netrin-1-targeted MBs were prepared using MicroMarker Target-Ready (VisualSonics), and validated in in vitro binding assays in static conditions or in a flow chamber using purified netrin-1 protein or netrin-1-expressing cancer cells. In vivo USMI of netrin-1 was validated in nude mice bearing human netrin-1-positive SKBR7 tumors or weakly netrin-1-expressing MDA-MB-231 tumors using the Vevo 2100 small animal imaging device (VisualSonics). USMI feasibility was further tested in transgenic murine FVB/N Tg(MMTV/PyMT634Mul) (MMTV-PyMT) mammary tumors. Results: Netrin-1 co-localized with endothelial CD31 in netrin-1-positive breast tumors. Netrin-1 binding to the surface of endothelial HUVEC and cancer cells was partially mediated by heparan sulfate proteoglycans. MBs targeted with humanized monoclonal anti-netrin-1 antibody bound to netrin-1-expressing cancer cells in static and dynamic conditions. USMI signal was significantly increased with anti-netrin-1 MBs in human SKBR7 breast tumors and transgenic murine MMTV-PyMT mammary tumors compared to signals recorded with either isotype control MBs or after blocking of netrin-1 with humanized monoclonal anti-netrin-1 antibody. In weakly netrin-1-expressing human tumors and normal mammary glands, no difference in imaging signal was observed with anti-netrin-1- and isotype control MBs. Ex vivo analysis confirmed netrin-1 expression in MMTV-PyMT tumors. Conclusions: These results show that USMI allowed reliable detection of netrin-1 on the endothelium of netrin-1-positive human and murine tumors. Significant differences in USMI signal for netrin-1 reflected the significant differences in netrin-1 mRNA & protein expression observed between different breast tumor models. The imaging approach was non-invasive and safe, and provided the netrin-1 expression status in near real-time. Thus, USMI of netrin-1 has the potential to become a companion diagnostic for the stratification of patients for netrin-1 interference therapy in future clinical trials.

Rotation-dependent nonlinear absorption of orbital angular momentum beams in ruby

We investigate the effect of a rotating medium on orbital angular momentum (OAM)-carrying beams by combining a weak probe beam shifted in frequency relative to a strong pump beam. We show how the rotational Doppler effect modifies the light-matter interaction through the external rotation of the medium. This interaction leads to an absorption that increases with the mechanical rotation velocity of the medium and with a rate that depends on the OAM of the light beam.

Intraoperative Resection Guidance with Photoacoustic and Fluorescence Molecular Imaging Using an Anti-B7-H3 Antibody-Indocyanine Green Dual Contrast Agent

Purpose: Breast cancer often requires surgical treatment including breast-conserving surgical resection. However, with current postsurgical histologic margin analysis, one quarter of breast cancer patients undergo reexcision to achieve negative margins corresponding to decreased local recurrence and better outcomes. Therefore, a method with high resolution and specificity for intraoperative margin assessment is needed.Experimental Design: First, quantitative immunofluorescence staining of B7-H3 expression was assessed in four pathologic stages of breast cancer progression of the MMTV-PyMT transgenic murine model. Next, an antibody-dye contrast agent, B7-H3-ICG, was injected into mice prior to surgical resection of breast cancer. Anatomic ultrasound, spectroscopic photoacoustic (sPA), and fluorescence imaging were used to guide resection of mammary glands suspected of containing cancer. Resected tissues were processed for H&E staining and pathologic assessment and compared with sPA and fluorescence imaging signals.Results: Tissue containing DCIS (46.0 ± 4.8 a.u.) or invasive carcinoma (91.7 ± 21.4 a.u.) showed significantly higher (P < 0.05) B7-H3 expression than normal and hyperplastic tissues (1.3 ± 0.8 a.u.). During image-guided surgical resection, tissue pieces assessed as normal or hyperplastic (n = 17) showed lower average sPA (3.17 ± 0.48 a.u.) and fluorescence signal [6.83E07 ± 2.00E06 (p/s)/(μW/cm²)] than DCIS and invasive carcinoma tissue (n = 63) with an average sPA signal of 23.98 ± 4.88 a.u. and an average fluorescence signal of 7.56E07 ± 1.44E06 (p/s)/(μW/cm²) with AUCs of 0.93 [95% confidence interval (CI), 0.87-0.99] and 0.71 (95% CI, 0.57-0.85), respectively.Conclusions: It was demonstrated that sPA and fluorescence molecular imaging combined with B7-H3-ICG agent can assess the disease status of tissues with high diagnostic accuracy, intraoperatively, with high resolution, sensitivity, and specificity. Clin Cancer Res; 24(15); 3572-82. ©2018 AACR.

Spine fracture prevalence in a nationally representative sample of US women and men aged ≥40 years: results from the National Health and Nutrition Examination Survey (NHANES) 2013-2014

Spine fracture prevalence is similar in men and women, increasing from <5 % in those <60 to 11 % in those 70-79 and 18 % in those ≥80 years. Prevalence was higher with age, lower bone mineral density (BMD), and in those meeting criteria for spine imaging. Most subjects with spine fractures were unaware of them.

INTRODUCTION

Spine fractures have substantial medical significance but are seldom recognized. This study collected contemporary nationally representative spine fracture prevalence data.

METHODS

Cross-sectional analysis of 3330 US adults aged ≥40 years participating in NHANES 2013-2014 with evaluable Vertebral Fracture Assessment (VFA). VFA was graded by semiquantitative measurement. BMD and an osteoporosis questionnaire were collected.

RESULTS

Overall spine fracture prevalence was 5.4 % and similar in men and women. Prevalence increased with age from <5 % in those <60 to 11 % in those 70-79 and 18 % in those ≥80 years. Fractures were more common in non-Hispanic whites and in people with lower body mass index and BMD. Among subjects with spine fracture, 26 % met BMD criteria for osteoporosis. Prevalence was higher in subjects who met National Osteoporosis Foundation (NOF) criteria for spine imaging (14 vs 4.7 %, P < 0.001). Only 8 % of people with a spine fracture diagnosed by VFA had a self-reported fracture, and among those who self-reported a spine fracture, only 21 % were diagnosed with fracture by VFA.

CONCLUSION

Spine fracture prevalence is similar in women and men and increases with age and lower BMD, although most subjects with spine fracture do not meet BMD criteria for osteoporosis. Since most (>90 %) individuals were unaware of their spine fractures, lateral spine imaging is needed to identify these women and men. Spine fracture prevalence was threefold higher in individuals meeting NOF criteria for spine imaging (∼1 in 7 undergoing VFA). Identifying spine fractures as part of comprehensive risk assessment may improve clinical decision making.

Spectroscopic Photoacoustic Molecular Imaging of Breast Cancer using a B7-H3-targeted ICG Contrast Agent

Purpose: Breast cancer imaging methods lack diagnostic accuracy, in particular for patients with dense breast tissue, and improved techniques are critically needed. The purpose of this study was to evaluate antibody-indocyanine green (ICG) conjugates, which undergo dynamic absorption spectrum shifts after cellular endocytosis and degradation, and spectroscopic photoacoustic (sPA) imaging to differentiate normal breast tissue from breast cancer by imaging B7-H3, a novel breast cancer associated molecular target.

Methods: Quantitative immunohistochemical staining of endothelial and epithelial B7-H3 expression was assessed in 279 human breast tissue samples, including normal (n=53), benign lesions (11 subtypes, n=129), and breast cancers (4 subtypes, n=97). After absorption spectra of intracellular and degraded B7-H3-ICG and Isotype control-ICG (Iso-ICG) were characterized, sPA imaging in a transgenic murine breast cancer model (FVB/N-Tg(MMTVPyMT)634Mul) was performed and compared to imaging of control conditions [B7-H3-ICG in tumor negative animals (n=60), Iso-ICG (n=30), blocking B7-H3+B7-H3-ICG (n=20), and free ICG (n=20)] and validated with ex vivo histological analysis.

Results: Immunostaining showed differential B7-H3 expression on both the endothelium and tumor epithelium in human breast cancer with an area under the ROC curve of 0.93 to differentiate breast cancer vs non-cancer. Combined in vitro/in vivo imaging showed that sPA allowed specific B7-H3-ICG detection down to the 13 nM concentration and differentiation from Iso-ICG. sPA molecular imaging of B7-H3-ICG showed a 3.01-fold (P<0.01) increase in molecular B7-H3-ICG signal in tumors compared to control conditions.

Conclusions: B7-H3 is a promising target for both vascular and epithelial sPA imaging of breast cancer. Leveraging antibody-ICG contrast agents and their dynamic optical absorption spectra allows for highly specific sPA imaging of breast cancer.

Photoacoustic Imaging in Oncology: Translational Preclinical and Early Clinical Experience

Photoacoustic imaging has evolved into a clinically translatable platform with the potential to complement existing imaging techniques for the management of cancer, including detection, characterization, prognosis, and treatment monitoring. In photoacoustic imaging, tissue is optically excited to produce ultrasonographic images that represent a spatial map of optical absorption of endogenous constituents such as hemoglobin, fat, melanin, and water or exogenous contrast agents such as dyes and nanoparticles. It can therefore provide functional and molecular information that allows noninvasive soft-tissue characterization. Photoacoustic imaging has matured over the years and is currently being translated into the clinic with various clinical studies underway. In this review, the current state of photoacoustic imaging is presented, including techniques and instrumentation, followed by a discussion of potential clinical applications of this technique for the detection and management of cancer. (©) RSNA, 2016.

Ultrasound Molecular Imaging of the Breast Cancer Neovasculature using Engineered Fibronectin Scaffold Ligands: A Novel Class of Targeted Contrast Ultrasound Agent

Molecularly-targeted microbubbles (MBs) are increasingly being recognized as promising contrast agents for oncological molecular imaging with ultrasound. With the detection and validation of new molecular imaging targets, novel binding ligands are needed that bind to molecular imaging targets with high affinity and specificity. In this study we assessed a novel class of potentially clinically translatable MBs using an engineered 10^th type III domain of human-fibronectin (MB-FN3_VEGFR2) scaffold-ligand to image VEGFR2 on the neovasculature of cancer. The in vitro binding of MB-FN3_VEGFR2 to a soluble VEGFR2 was assessed by flow-cytometry (FACS) and binding to VEGFR2-expressing cells was assessed by flow-chamber cell attachment studies under flow shear stress conditions. In vivo binding of MB-FN3_VEGFR2 was tested in a transgenic mouse model (FVB/N Tg(MMTV/PyMT634Mul) of breast cancer and control litter mates with normal mammary glands. In vitro FACS and flow-chamber cell attachment studies showed significantly (P<0.01) higher binding to VEGFR2 using MB-FN3_VEGFR2 than control agents. In vivo ultrasound molecular imaging (USMI) studies using MB-FN3_VEGFR2 demonstrated specific binding to VEGFR2 and was significantly higher (P<0.01) in breast cancer compared to normal breast tissue. Ex vivo immunofluorescence-analysis showed significantly (P<0.01) increased VEGFR2-expression in breast cancer compared to normal mammary tissue. Our results suggest that MBs coupled to FN3-scaffolds can be designed and used for USMI of breast cancer neoangiogenesis. Due to their small size, stability, solubility, the lack of glycosylation and disulfide bonds, FN3-scaffolds can be recombinantly produced with the advantage of generating small, high affinity ligands in a cost efficient way for USMI.

Breast Cancer Detection by B7-H3-Targeted Ultrasound Molecular Imaging

Ultrasound complements mammography as an imaging modality for breast cancer detection, especially in patients with dense breast tissue, but its utility is limited by low diagnostic accuracy. One emerging molecular tool to address this limitation involves contrast-enhanced ultrasound using microbubbles targeted to molecular signatures on tumor neovasculature. In this study, we illustrate how tumor vascular expression of B7-H3 (CD276), a member of the B7 family of ligands for T-cell coregulatory receptors, can be incorporated into an ultrasound method that can distinguish normal, benign, precursor, and malignant breast pathologies for diagnostic purposes. Through an IHC analysis of 248 human breast specimens, we found that vascular expression of B7-H3 was selectively and significantly higher in breast cancer tissues. B7-H3 immunostaining on blood vessels distinguished benign/precursors from malignant lesions with high diagnostic accuracy in human specimens. In a transgenic mouse model of cancer, the B7-H3-targeted ultrasound imaging signal was increased significantly in breast cancer tissues and highly correlated with ex vivo expression levels of B7-H3 on quantitative immunofluorescence. Our findings offer a preclinical proof of concept for the use of B7-H3-targeted ultrasound molecular imaging as a tool to improve the diagnostic accuracy of breast cancer detection in patients.

Ultrasound and microbubble guided drug delivery: mechanistic understanding and clinical implications

Ultrasound mediated drug delivery using microbubbles is a safe and noninvasive approach for spatially localized drug administration. This approach can create temporary and reversible openings on cellular membranes and vessel walls (a process called "sonoporation"), allowing for enhanced transport of therapeutic agents across these natural barriers. It is generally believed that the sonoporation process is highly associated with the energetic cavitation activities (volumetric expansion, contraction, fragmentation, and collapse) of the microbubble. However, a thorough understanding of the process was unavailable until recently. Important progress on the mechanistic understanding of sonoporation and the corresponding physiological responses in vitro and in vivo has been made. Specifically, recent research shed light on the cavitation process of microbubbles and fluid motion during insonation of ultrasound, on the spatio-temporal interactions between microbubbles and cells or vessel walls, as well as on the temporal course of the subsequent biological effects. These findings have significant clinical implications on the development of optimal treatment strategies for effective drug delivery. In this article, current progress in the mechanistic understanding of ultrasound and microbubble mediated drug delivery and its implications for clinical translation is discussed.

Multiparametric spectroscopic photoacoustic imaging of breast cancer development in a transgenic mouse model

Objective: To evaluate the potential of multiparametric spectroscopic photoacoustic imaging using oxygen saturation, total hemoglobin, and lipid content to differentiate among four different breast histologies (normal, hyperplasia, ductal carcinoma in situ (DCIS), and invasive breast carcinoma) in a transgenic mouse model of breast cancer development.

Materials and Methods: Animal studies were approved by the Institutional Administrative Panel on Laboratory Animal Care. Mammary glands (n=251) of a transgenic mouse model of breast cancer development (FVB/N-Tg(MMTV-PyMT)634Mul) were imaged using B-mode ultrasound and spectroscopic photoacoustic imaging, analyzed for oxygen saturation, total hemoglobin, and lipid content, and processed for histological analysis. Statistical analysis was performed using one-way ANOVA, two-sample t-tests, logistic regression, and ROC analysis.

Results: Eighty-two normal, 12 hyperplastic, 96 DCIS, and 61 invasive breast carcinoma mammary glands were analyzed. Based on spectroscopic photoacoustic imaging, the oxygen saturation of hyperplasia (50.6%), DCIS (43.0%), and invasive carcinoma (46.2%) significantly increased compared to normal glands (35.5%, P <0.0001), while both total hemoglobin (P<0.01), and lipid content (P<0.0008) significantly decreased with advancing histology. In differentiating normal and hyperplasia from DCIS and invasive breast carcinoma, multiparametric imaging of oxygen saturation, lipid content, and raw photoacoustic signal at 750 nm provided an AUC value of 0.770.

Conclusion: Multiparametric spectroscopic photoacoustic imaging is feasible and allows detection of differences in concentration of tissue chromophores among different histologies in a transgenic mouse model of breast cancer development.

Escorts' knowledge of their duty of care to patients who have undergone intravenous sedation

AIM

To assess escorts' understanding of their responsibilities to the patient 24 hours following dental treatment under intravenous sedation.

STANDARDS

One hundred per cent of escorts: have been informed of their duties, have read the information sheet, expect at least a one hour appointment, identify the hazardous activities patients should avoid following sedation, travel by private transport, are aware that medications are taken as normal, should have care in place 24 hours following sedation.

METHOD

This was a prospective questionnaire-based audit. Questionnaires were handed to escorts of patients receiving treatment under intravenous sedation in Newcastle Dental Hospital sedation department.

RESULTS

Of 104 responses, 91.3% of escorts were informed about their duties and 79.8% had read the information sheet prior to the appointment. Boiling a kettle and Internet use were the most selected hazardous activities that escorts deemed safe for patients to carry out postoperatively (19.2%, 23.0%.) Private transport home was mainly used (car 73.1%, taxi 24.9%.) Following sedation, 93.3% of patients had an escort for 24 hours.

CONCLUSION

Escorts' basic knowledge fell short of the standard. Improvements are needed to ensure patient safety.

RECOMMENDATIONS

At the pre-assessment, the patient might be given an information sheet solely for the escort and encouraged to explain this to the escort. More comprehensive information listing activities hazardous to the patient 24 hours following sedation and emphasising that taking medications as normal preoperatively could be available on the treatment day. Transport information in the appointment letter might improve access. A Trust website link, a DVD and posters in the waiting room could further inform.

Acoustic and photoacoustic molecular imaging of cancer

Ultrasound and combined optical and ultrasonic (photoacoustic) molecular imaging have shown great promise in the visualization and monitoring of cancer through imaging of vascular and extravascular molecular targets. Contrast-enhanced ultrasound with molecularly targeted microbubbles can detect early-stage cancer through the visualization of targets expressed on the angiogenic vasculature of tumors. Ultrasonic molecular imaging can be extended to the imaging of extravascular targets through use of nanoscale, phase-change droplets and photoacoustic imaging, which provides further molecular information on cancer given by the chemical composition of tissues and by targeted nanoparticles that can interact with extravascular tissues at the receptor level. A new generation of targeted contrast agents goes beyond merely increasing imaging signal at the site of target expression but shows activatable and differential contrast depending on their interactions with the tumor microenvironment. These innovations may further improve our ability to detect and characterize tumors. In this review, recent developments in acoustic and photoacoustic molecular imaging of cancer are discussed.

PTPN14 interacts with and negatively regulates the oncogenic function of YAP

The Hippo signaling pathway regulates cellular proliferation and survival, thus exerting profound effects on normal cell fate and tumorigenesis. The pivotal effector of this pathway is YAP, a transcriptional co-activator amplified in mouse and human cancers where it promotes epithelial-to-mesenchymal transition and malignant transformation. Here, we report a novel regulatory mechanism for the YAP oncogenic function via direct interaction with non-receptor tyrosine phosphatase 14 (PTPN14) through the WW domain of YAP and the PPxY domain of PTPN14. We also found that YAP is a direct substrate of PTPN14. In addition, luciferase reporter assay showed that the inhibition of the YAP transcriptional co-activator function by PTPN14 is mediated through their protein interactions and may result from an increase in the inactive cytoplasmic form of YAP. Last, knockdown of PTPN14 induces the nuclear retention of YAP and increases the YAP-dependent cell migration. In summary, our results indicate a potential regulatory role of PTPN14 on YAP and demonstrate a novel mechanism in YAP regulation.

Differences in structural geometrical outcomes at the neck of the proximal femur using two-dimensional DXA-derived projection (APEX) and three-dimensional QCT-derived (BIT QCT) techniques

Structural geometric parameters at neck of the proximal femur were obtained using DXA-derived hip structural analysis (APEX 3) and quantitative computed tomography-derived (BIT QCT) techniques in 237 elderly females. Linear correlations for parameters ranged from 0.45 to 0.90. The average value of the subperiosteal width, as determined by the two techniques, was the same; variables dependent on mass measurements were different.

INTRODUCTION

There has been increasing interest in using bone structural geometry to assess bone fragility to complement bone mineral mass. The objective of this study is to compare structural geometrical differences between "2D" DXA-derived and "3D" QCT-derived techniques in unselected clinical cases.

METHODS

All 237 females had both DXA and QCT assessments of femoral neck structural geometry. Variables compared were areal bone mineral density, cross-sectional area (CSA), cross-sectional moment of inertia (CSMI), section modulus (Z), averaged cortical thickness (Ct), endosteal width (ESW), subperiosteal width (W), and buckling ratio (BR).

RESULTS

Correlation of femoral neck variables ranged from 0.45 for ESW to 0.90 for CSA. APEX 3 and BIT QCT-derived femoral neck W values were numerically similar. However CSA, CSMI, Z and Ct values measured by APEX 3 were higher and ESW and BR values were lower than corresponding BIT QCT.

CONCLUSIONS

2D DXA structural analysis of neck of femur is related to but different from same parameters calculated from true 3D images obtained by CT. Femoral neck size values are similar for DXA and QCT, but structural geometrical variables dependent on mass calibration standards, location of neck ROI and mathematical derivation techniques are different.

Advances in Clinical and Biomedical Applications of Photoacoustic Imaging

IMPORTANCE OF THE FIELD: Photoacoustic imaging is an imaging modality that derives image contrast from the optical absorption coefficient of the tissue being imaged. The imaging technique is able to differentiate between healthy and diseased tissue with either deeper penetration or higher resolution than other functional imaging modalities currently available. From a clinical standpoint, photoacoustic imaging has demonstrated safety and effectiveness in diagnosing diseased tissue regions using either endogenous tissue contrast or exogenous contrast agents. Furthermore, the potential of photoacoustic imaging has been demonstrated in various therapeutic interventions ranging from drug delivery and release to image-guided therapy and monitoring. AREAS COVERED IN THIS REVIEW: This article reviews the current state of photoacoustic imaging in biomedicine from a technological perspective, highlights various biomedical and clinical applications of photoacoustic imaging, and gives insights on future directions. WHAT THE READER WILL GAIN: Readers will learn about the various applications of photoacoustic imaging, as well as the various contrast agents that can be used to assist photoacoustic imaging. This review will highlight both pre-clinical and clinical uses for photoacoustic imaging, as well as discuss some of the challenges that must be addressed to move photoacoustic imaging into the clinical realm. TAKE HOME MESSAGE: Photoacoustic imaging offers unique advantages over existing imaging modalities. The imaging field is broad with many exciting applications for detecting and diagnosing diseased tissue or processes. Photoacoustics is also used in therapeutic applications to identify and characterize the pathology and then to monitor the treatment. Although the technology is still in its infancy, much work has been done in the pre-clinical arena, and photoacoustic imaging is fast approaching the clinical setting.

Anxiety and quality of life in phobic dental patients

Little is known about the anxiety patients experience before attending for dental treatment. The aim of this study was to determine, in dentally phobic patients, the temporal relationship of pre-operative anxiety levels, and the disruption to daily life caused by this. Twenty-four phobic and 19 comparison (non-phobic) dental patients were recruited. Four validated questionnaires were used to assess anxiety and quality of life, which each patient completed for 5 days prior to, and on the day of, treatment. Those in the experimental group were found to have significantly greater levels of dental and general anxiety, and a significantly lower quality of life compared with those in the comparison group. Significant temporal relationships were found with all of the questionnaires. Dental and general anxiety scores were significantly correlated with quality-of-life measures. This study suggests that phobic dental patients are experiencing significant increased anxiety, and significant negative quality-of-life effects, in this period.

Comparison of transmucosal midazolam with inhalation sedation for dental extractions in children. A randomized, cross-over, clinical trial

BACKGROUND

The transmucosal route for conscious sedation in children has been reported widely in the field of medicine, but less so in dental patients. The aim of this study was to evaluate the efficacy and safety profile of midazolam (0.2 mg/kg) administered by the buccal transmucosal route, in comparison with nitrous oxide/oxygen inhalation sedation, for orthodontic extractions in 10-16-year-old dental patients.

METHODS

Each patient attended for two visits and was randomly allocated to receive buccal midazolam (0.2 mg/kg) or nitrous oxide/oxygen titrated to 30%/70% at the first visit, the alternative being used at the second visit. The patients' vital signs, sedation levels and behavioural scores were recorded throughout. Post-operatively, side-effects, recall of the visit and satisfaction levels were recorded via questionnaire.

RESULTS

Thirty-six patients, with a mean age of 12.9 years, completed both arms of the trial. The maximum level of sedation was achieved with buccal midazolam in a mean time of 14.42 min, compared with 7.05 min with inhalation sedation. The vital signs with both types of sedation remained within acceptable limits and the reported side-effects were of no clinical significance. Buccal midazolam was found to be acceptable by 65.7%. Only 28.6% of cases preferred this technique, the main disadvantage being the taste of the solution.

CONCLUSION

Buccal midazolam sedation (0.2 mg/kg) seems to be equally as safe and effective as nitrous oxide/oxygen for the extraction of premolar teeth in anxious children. However, further research is required to refine the midazolam vehicle to improve acceptability.

A comparison of oral midazolam and nitrous oxide sedation for dental extractions in children

The aim of the study was to compare oral midazolam and inhaled nitrous oxide as sedative agents during the management of children aged 5-10 years presenting for extraction of primary teeth under local anaesthetic. Subjects required two visits for the extraction of four primary teeth, one in each quadrant of the mouth, and were randomly allocated to be given nitrous oxide 30% in oxygen or oral midazolam 0.3 mg.kg(-1) at the first visit, the other technique being used at the second visit. Vital signs, sedation levels and behavioural scores were recorded, and postoperative recall and satisfaction were reported by the patients. Thirty-five children, with a mean [range] age of 7.4 [5-10] years, completed the treatment. The mean dose of oral midazolam given was 8.6 [3.3-16.5] mg. The mean times taken to achieve the maximum level of sedation for midazolam and nitrous oxide sedation were 15.9 [2-30] min and 6.8 [2-10] min, respectively. Physiological parameters remained within acceptable clinical limits for both types of sedation. Oral midazolam was considered acceptable by 59% and was preferred by 36%. Oral midazolam sedation in 5 to 10-year-old children was shown to be as safe and effective as nitrous oxide in oxygen sedation for extraction of primary teeth but would not be the method of choice for all patients.

SNCA multiplication is not a common cause of Parkinson disease or dementia with Lewy bodies

The authors recently have shown that triplication of the alpha-synuclein gene (SNCA) can cause Parkinson disease (PD) and diffuse Lewy body disease within the same kindred. The authors assessed 101 familial PD probands, 325 sporadic PD cases, 65 patients with dementia with Lewy bodies, and 366 neurologically normal control subjects for SNCA multiplication. The authors did not identify any subjects with multiplication of SNCA and conclude this mutation is a rare cause of disease.

High throughput approaches in neuroscience

Traditional approaches to understanding biological problems are now being advanced with the use of high throughput technologies, which analyse multiple samples simultaneously, or thousands of analytes in a single sample. The application of these technologies in neurochemistry and neuroscience is beginning to be explored and is assisting in the development of new models of drug action, neuroanatomical investigations, and in identifying molecular pathways involved in neurological and psychiatric disease. Tools such as microarray-based gene expression profiling and 2D and multidimensional proteomic methods are uncovering functional components to a wide variety of neuroscience paradigms and the application of these technologies is set to become standard in analysis.

Functional genomics and proteomics: application in neurosciences

The sequencing of the complete genome for many organisms, including man, has opened the door to the systematic understanding of how complex structures such as the brain integrate and function, not only in health but also in disease. This blueprint, however, means that the piecemeal analysis regimes of the past are being rapidly superseded by new methods that analyse not just tens of genes or proteins at any one time, but thousands, if not the entire repertoire of a cell population or tissue under investigation. Using the most appropriate method of analysis to maximise the available data therefore becomes vital if a complete picture is to be obtained of how a system or individual cell is affected by a treatment or disease. This review examines what methods are currently available for the large scale analysis of gene and protein expression, and what are their limitations.

A survey of the opinions of consultant anaesthetists in Scotland of sedation carried out by dentists

OBJECTIVES

To elicit the attitudes and opinions of consultant anaesthetists working in Scotland, with regard to conscious sedation carried out by dental practitioners.

METHOD

A questionnaire was designed to gauge opinion of consultant anaesthetists in Scotland on the practice of conscious sedation by dentists. The questionnaire was sent to 353 consultant anaesthetists working in 49 hospitals within the 15 health boards in Scotland.

RESULTS

Of the 366 questionnaires sent, 249 were returned of which 235 were valid. This gave a response rate of 64%. In general, those questioned felt that the provision of sedation in a hospital setting was more appropriate than in general dental practice. A majority (65%) thought that it was unrealistic for anaesthetists to provide all sedation for dental treatment, although many (58%) felt that anaesthetists should take more responsibility in this area. Again, a majority (60%) agreed that dentists should be trained to use sedation techniques for their patients but a significant number (63%) disagreed with the practice of operator/sedationist.

CONCLUSION

It is of concern to the dental profession that a significant number of anaesthetists do not feel that it is appropriate for dentists to be administering even the most simple methods of sedation. At present there are no clear, recognised guidelines as to the level of formal training required for the practice of conscious sedation by dentists. It is in the interests of the dental profession and the public to ensure that those choosing to practice sedation do so safely by following recognised guidelines in the training and practice of sedation.

Randomized, controlled, cross-over clinical trial comparing intravenous midazolam sedation with nitrous oxide sedation in children undergoing dental extractions

BACKGROUND

The use of benzodiazepines for paediatric dental sedation has received limited attention with regard to research into clinical effectiveness. A study was therefore designed to investigate the use of midazolam, for i.v. sedation in paediatric dental patients.

METHOD

The aim of the study was to assess the effectiveness of i.v. midazolam in a randomized, controlled, cross-over trial. Children aged 12-16 yr (ASA I and II), requiring two appointments for equivalent but contralateral dental extractions for orthodontic purposes, were recruited. Conscious sedation with either i.v. midazolam titrated at 0.5 mg x min(-1), to a maximum of 5 mg, or nitrous oxide/oxygen titrated to 30%/70% inhalation sedation was used at the first visit, the alternative being used at the second visit. Vital signs including blood pressure, arterial oxygen saturation and ventilatory frequency, as well as sedation levels and behavioural scores, were recorded every 2 min.

RESULTS

Forty patients, mean age 13.2 yr (range 12-16 yr), participated in the trial. A mean dose of midazolam 2.8 mg was administered in the test group. The median time to the maximum level of sedation was 8 min for midazolam compared with 6 min for nitrous oxide (P<0.001). Vital signs for both treatments were comparable and within acceptable clinical limits and communication with the patient was maintained at all times. The median (range) lowest arterial oxygen saturation level recorded for midazolam was 97 (91-99)% compared with 97 (92-100)% for nitrous oxide. The mean (range) recovery time for midazolam was 51.6 (39-65) min and 23.3 (20-34) min for nitrous oxide (P<0.0001). Fifty-one per cent said they preferred i.v. midazolam, 38% preferred nitrous oxide, and 11% had no preference.

CONCLUSION

I.V. midazolam sedation (0.5 mg x min(-1) to a maximum of 5 mg) appears to be as effective as nitrous oxide sedation in 12-16-yr-old healthy paediatric dental patients.

A randomised, controlled, crossover trial of oral midazolam and nitrous oxide for paediatric dental sedation

A randomised, controlled, crossover trial was designed to assess the safety and effectiveness of oral midazolam sedation for orthodontic extractions. Forty-six ASA physical status I children aged 10-16 years were recruited. Each child required two treatment sessions. Sedation with either oral midazolam 0.5 mg.kg-1 or nitrous oxide in oxygen was used at the first visit, the alternative being used at the second visit. Blood pressure, heart rate, arterial oxygen saturation, and sedation and behavioural scores were recorded every 5 min. Anxiety levels and postoperative satisfaction were also recorded. Blood pressure, heart rate and arterial oxygen saturation in both groups were similar and within acceptable clinical limits. The median [range] lowest arterial oxygen saturation levels for subjects in the midazolam and nitrous oxide groups were 95 [90-100]% and 98 [93-100]%, respectively. The median [range] time to the maximum level of sedation in the midazolam group was 20 [5-65] min compared with 5 [5-10] min in the nitrous oxide group (p < 0.001). The median [range] duration of treatment was similar in both groups (midazolam group: 10 [5-30] min, nitrous oxide group: 10 [5-25] min). Seventy-four per cent of subjects were prepared to have oral midazolam sedation again, 54% preferring it. Oral midazolam appears to be a safe and acceptable form of sedation for 10-16-year-old paediatric dental patients.

Bordetella pertussis isolates with a heterogeneous phenotype for erythromycin resistance

Erythromycin is currently being used for both prophylaxis and treatment of pertussis infections. Erythromycin resistance was first recognized in Bordetella pertussis in Arizona in 1994, and since then, three additional resistant isolates have been identified in the United States. To better assess the potential public health impact of erythromycin-resistant B. pertussis, we used the disk diffusion assay to evaluate the frequency of erythromycin resistance among 1,030 recently circulating U.S. isolates and found the rate of occurrence to be <1%. We also describe a novel heterogeneous phenotype, with erythromycin-resistant colonies appearing only after a 7-day incubation period. To optimize patient management, we recommend that clinicians be alert to potential treatment failures and that laboratorians use a 7-day incubation period when screening for resistance. Our ongoing national surveillance will continue to monitor for resistant B. pertussis isolates and their potential association with changing pertussis epidemiology.

A study of the effectiveness of oral midazolam sedation for orthodontic extraction of permanent teeth in children: a prospective, randomised, controlled, crossover trial

OBJECTIVES

To assess the safety, effectiveness and acceptability of o:ral midazolam sedation for orthodontic extraction of permanent teeth in children.

DESIGN

A prospective, randomised, controlled, crossover trial.

METHODS

A total of 26 children aged 10-16 (ASA I), referred for orthodontic extraction of premolar or canine teeth under sedation, were included in the study. Each child required two treatment sessions for the extraction of equivalent teeth on opposite sides of the mouth. Each subject was sedated with either ora midazolam (0.5 mg/kg) or nitrous oxide and oxygen (30%/70%) at the first visit and the alternative form at the second visit. At each visit two teeth were extracted, one upper and one lower. Heart rate, arterial oxygen saturation, respiration rate, sedation and behavioural scores were recorded every five minutes. Overall behaviour, patient acceptance and patient satisfaction were recorded at the end of treatment.

RESULTS

Of the 26 children included in the study there were 12 males and 14 females. The mean age was 12.5 years. The mean heart rate and respiratory rate for both groups were similar and within acceptable clinical limits. The lowest mean arterial oxygen saturation levels for nitrous oxide and midazolam sedation were 97.7% and 95.0% respectively. Although midazolam caused greater oxygen desaturation, the range (91%-100%) was within safe limits for conscious sedation. The mean level of sedation was greater in the midazolam group compared with the nitrous oxide group and all but one case completed treatment. A total of 23 patients (88%) said they would be prepared to have ora midazolam sedation again and 17 (65%) actually preferred oral midazolam to nitrous oxide sedation.

CONCLUSION

Oral midazolam (0.5mg/kg) appears to be a safe and acceptable form of sedation for 10-16 year old paediatric dental patients.

Antimicrobial activity of ergokonin A from Trichoderma longibrachiatum

AIMS

Natural fungal products were screened for antifungal compounds. The mode of action of one of the hits found and the taxonomy of the producing organism were analysed.

METHODS AND RESULTS

An extract from a Trichoderma species showed a more potent activity in an agar-based assay against the null mutant fks1::HIS strain than against the wild-type strain, suggesting that it could contain a glucan synthesis inhibitor. The active component was identified as the known compound ergokonin A. The compound exhibited activity against Candida and Aspergillus species, but was inactive against Cryptococcus species. It induced alterations in the hyphal morphology of Aspergillus fumigatus. The identification of the producing isolate was confirmed by sequencing of the rDNA internal transcribed spacers and comparison with the sequences of other Trichoderma species. The analysis showed that the producing fungus had a high homology with other strains classified as Trichoderma longibrachiatum and its teleomorph Hypocrea schweinitzii.

CONCLUSIONS

The antifungal activity spectrum of ergokonin A and the morphology alterations induced on A. fumigatus are consistent with glucan synthesis as the target for ergokonin A. The production of ergokonin A is not uncommon, but is probably restricted to Trichoderma species.

SIGNIFICANCE AND IMPACT OF THE STUDY

The discovery that ergokonin A could be an inhibitor of glucan synthesis, having a structure very different to other inhibitors, increases the likelihood that orally active agents with this fungal-specific mode of action may be developed.

Effects of ultraviolet-A exposure on ultraviolet-B-induced accumulation of specific flavonoids in Brassica napus

Many plant species are able to acclimate to changes in ultraviolet-B radiation (UVB) (290-320 nm) exposure. Due to the wide range of targets of UVB, plants have evolved diverse repair and protection mechanisms. These include increased biosynthesis of UVB screening compounds, elevated antioxidant activity and increased rates of DNA repair. We have shown previously that Brassica napus L. cv Topas plants can acclimate quite effectively to environmentally relevant increases in UVB through the accumulation of specific flavonoids in the leaf epidermis. However, B. napus was found to lose other flavonoids when plants are exposed to ultraviolet-A radiation (UVA) (320-400 nm) and/or UVB (Wilson et al. [1998] Photochem. Photobiol. 67, 547-553). In this study we demonstrate that the levels of all the extractable flavonoids in the leaves of B. napus plants are decreased in a dose-dependent manner in response to UVA exposure. Additionally, the accumulation of the extractable flavonoids was examined following a shift from photosynthetically active radiation (PAR) + UVA to PAR + UVB to assess if preexposure to UVA affected UVB-induced flavonoid accumulation. UVA preexposures were found to impede UVB-induced accumulation of some flavonoids. This down regulation was particularly evident for quercetin-3-O-sophoroside and quercetin-3-O-sophoroside-7-O-glucoside, which is interesting because quercetins have been demonstrated to be induced by UVB and correlated with UVB tolerance in some plant species. The photobiological nature of these UVA-mediated effects on flavonoid accumulation implies complex interactions between UVA and UVB responses.

Rheumatoid arthritis synovial T cells regulate transcription of several genes associated with antigen-induced anergy

Rheumatoid arthritis (RA) is a chronic, inflammatory synovitis whose pathogenesis may involve autoimmune mechanisms. Anergy is a state of T-cell nonresponsiveness characterized by downregulated IL-2 production. Paradoxically, RA T cells are hyporesponsive and proliferate poorly to antigens and mitogens, thus sharing some characteristics with anergic T cells. We analyzed the molecular basis of anergy in cloned human CD4+ T cells using differential display RT-PCR and subsequently examined the levels of differentially expressed transcripts in RA and, as control, reactive arthritis (ReA) synovium. Several transcriptional events were common to anergic T cells and RA synovium. These included downregulation of CALMODULIN:, which is critical to T-cell activation, and of cellular apoptosis susceptibility protein, which may mediate resistance to apoptosis in RA. Transcription of CALMODULIN: in RA synovium was less than 1% of that in ReA and was lower in RA synovial fluid mononuclear cells than in paired PBMCs. Following anti-TNF-alpha therapy in vivo, RA PBMC CALMODULIN: transcripts increased five- to tenfold. Pharmacological calmodulin blockade in vitro impaired antigen-specific proliferation. These data provide a link between reduced CALMODULIN: transcription and impaired T-cell responsiveness in RA. The identification of transcriptional changes common to anergic and RA synovial T cells should help interpret some of the characteristic RA cellular defects.

The role of growth rate, redox-state of the plastoquinone pool and the trans-thylakoid deltapH in photoacclimation of Chlorella vulgaris to growth irradiance and temperature

The long-term photoacclimation of Chlorella vulgaris Beijer (UTEX 265) to growth irradiance and growth temperature under ambient CO2 conditions was examined. While cultures grew at a faster rate at 27 than at 5 degrees C, growth rates appeared to be independent of irradiance. Decreases in light-harvesting polypeptide accumulation, increases in xanthophyll pool size and changes in the epoxidation state of the xanthophyll cycle pigments were correlated linearly with increases in the relative reduction state of QA, the primary quinone receptor of photosystem II, when estimated as 1-qP under steady-state growth conditions. However, we show that there is also a specific temperature-dependent component, in addition to the redox-state of the QA, involved in regulating the content and composition of light-harvesting complex II of C. vulgaris. In contrast, modulation of the epoxidation state of the xanthophyll pool in response to increased 1-qP in cells grown at 5 degrees C was indistinguishable from that of cells grown at 27 degrees C, indicating that light and temperature interact in a similar way to regulate xanthophyll cycle activity in C. vulgaris. Because C. vulgaris exhibited a low-light phenotype in the presence of 3-(3,4-dichlorophenyl)-1,1-dimethylurea (DCMU), but a high-light phenotype upon addition of 2,5-dibromo-6-isopropyl-3-methyl-1,4-benzoquinone, we conclude that the plastoquinone pool acts as a sensor regulating the accumulation of light-harvesting polypeptides in C. vulgaris. However, concomitant measurements of non-photochemical fluorescence quenching (qN) and the epoxidation state of the xanthophyll pool appear to indicate that, in addition to the redox-state of the plastoquinone pool, the trans-thylakoid deltapH may also contribute to sensing changes in irradiance and temperature that would lead to over-excitation of the photosynthetic apparatus. We suggest that sink capacity as reflected in photosynthate utilization and cell growth ultimately regulate photoacclimation in C. vulgaris.

A prospective randomised controlled study of patient-controlled propofol sedation in phobic dental patients

The safety and effectiveness of patient-controlled propofol sedation was prospectively assessed in 18 healthy, phobic dental patients. Using a randomised, crossover design each patient received two sessions of equivalent dental treatment under patient-controlled or clinician-controlled propofol sedation. The patient-controlled technique used 29.8% less drug (time-weighted dose) than the clinician-controlled method (p = 0.011). There was a high correlation between number of demands and number of doses actually infused during the patient-controlled technique (r = 0.99, p < 0. 001). Clinically, the level of sedation was lighter and the degree of operator satisfaction was higher with patient-controlled sedation. Blood pressure and arterial oxygen saturation showed minimal changes and remained within normal ranges during both techniques. Patient-controlled sedation produced a greater reduction in dental and general anxiety compared with clinician-controlled sedation, but the difference did not reach statistical significance. Three times the number of patients expressed a preference for the patient-controlled, compared with the clinician-controlled, technique. Patient-controlled sedation provides safe and acceptable intra-operative anxiolysis for phobic dental patients, but with reduced propofol dosage.

Beta 1 integrin- and proteoglycan-mediated stimulation of T lymphoma cell adhesion and mitogen-activated protein kinase signaling by thrombospondin-1 and thrombospondin-1 peptides

Cell-cell and cell-matrix interactions play important regulatory roles in lymphocyte homeostasis. Thrombospondin-1 (TSP1) is a matricellular protein that differentially promotes the adhesion of resting and activated T cells. In this work, we show that adhesion of Jurkat T cells on substrates coated with TSP1 or TSP1-derived peptides is mediated by beta 1 integrins, CD47, and heparan sulfate proteoglycans. Interactions with TSP1 or TSP1 peptides stimulated CD3-induced Ras activation and tyrosine phosphorylation of several T cell proteins. The signals from TSP1 and its derived peptides differentially synergized with activation of the TCR to induce phosphorylation of linker for activation of T cells (LAT) and extracellular signal-regulated kinase (ERK) 1/2, c-Jun N-terminal kinase, and p38 kinases. The phosphorylation of ERK in the presence of full-length TSP1 was transient and dependent on a beta 1 integrin receptor. Interestingly, peptides derived from the type 1 repeats of TSP1 and a CD47-binding peptide from the carboxyl-terminal domain of TSP1 also stimulated mitogen-activated protein (MAP) kinase phosphorylation. Moreover, the TSP1 heparin-binding peptide synergized with Ab-ligated TCR to transduce signals to the nucleus, detected by activation of AP-1- and Elk-dependent transcription. This TSP1 peptide-dependent activation of AP-1 was inhibited by both heparin and the MAP/ERK kinase inhibitor PD98059, providing a functional link between adhesion molecule interaction and nuclear transactivation events via the MAP kinase pathways. These findings have implications for the role of extracellular TSP1 and TSP1 fragments in the regulation of T cell function during hemostasis, wound repair, and other inflammatory responses.

Regulation and function of the extracellular matrix protein tenascin-C in ovarian cancer cell lines

The extracellular matrix glycoprotein tenascin-C (TN) is overexpressed in the stroma of malignant ovarian tumours particularly at the interface between epithelia and stroma leading to suggestions that it may be involved in the process of invasion (Wilson et al (1996) Br J Cancer 74: 999-1004). To define regulation of TN further and investigate its function in ovarian cancer, a range of cell line models were studied. Concentrations of secreted TN in media from cultures of ovarian fibroblast cell lines were at least 100-fold greater than from carcinoma cell lines. Evidence for paracrine regulation of TN secretion was obtained by co-culture of carcinoma cells with fibroblast cells wherein secretion into the media was greater than from fibroblasts alone. Transforming growth factor (TGF)-beta1, insulin-like growth factor (IGF)-II and progesterone all stimulated TN secretion while human choriogonadotropin (hCG), follicle-stimulating hormone (FSH) and gamma-interferon inhibited secretion. TGF-beta1 produced the greatest stimulation of TN in cultured fibroblasts and its co-expression with TN was examined in primary ovarian tumours. There was a significant association between the presence of moderate-strong expression of TN and TGF-beta1. Evidence for TN having a functional role in ovarian carcinoma was obtained from adhesion and migration assays. The PE01, PE04, SKOV-3 and 59M cell lines all demonstrated marked adhesion to plastic coated with TN relative to the control protein bovine serum albumin (BSA) and expressed alpha2beta1 and alpha3beta1 integrins. The SKOV-3 cell line migrated more rapidly through TN than through BSA indicating that TN can facilitate migration of ovarian carcinoma cells.

Organometallic flavonoid derivatives as spectroscopic probes

Derivatives of naringenin have been synthesized with organometalcarbonyl reporting groups for IR spectroscopy attached at C-2, C-3', or C-6, and the products have been tested for the induction of nod gene expression using a Rhizobium leguminosarum strain which contains the Escherichia coli lacZ (beta-galactosidase) gene fused to nodABC. Derivatives with an OMe substituent within the reporting group moiety showed residual gene induction activity.

Advantages of impact testing over hardness testing in determining physical integrity of tablets

An investigation of four different tablet strength tests was carried out on four different placebo formulations (differing in Avicel: Pharmatose ratios). The results analysis compared fatigue failure, work of failure, and impact failure to diametrical compression measurements (hardness). The impact results clearly show how different formulations can have the same hardness, yet their impact resistance can vary by as much as 200%. The impact test used in this work and other tests described are useful in tablet development to understand, compare, and mitigate tablet breakage during subsequent unit operations.

Earth-to-deep-space optical communications system with adaptive tilt and scintillation correction by use of near-Earth relay mirrors

Performance of an Earth-to-deep-space optical telecommunications system is degraded by distortion of the beam as it propagates through the turbulent atmosphere. Conventional approaches to correcting distortions, based on natural or artificial guide stars, have practical difficulties or are not adequate for correction of distortions, which are important for Earth-to-deep-space optical links. A beam-relay approach that overcomes these difficulties is discussed. A downward-directed laser near an orbiting relay mirror provides a reference for atmospheric correction. Adaptive optics at the ground station compensate the uplink beam so that after it passes through the atmosphere uplink propagation effects are removed. The orbiting mirror then directs the corrected beam to the distant spacecraft.

Summation of extraocular motor unit tensions in the lateral rectus muscle of the cat

Contractile measures on 67 single muscle units in the cat lateral rectus muscle were made in response to motoneuron stimulation. Simultaneous activation of four to five additional units, using muscle nerve stimulation, allowed an examination of unit force summation. Linear force addition was found in 73% of the units, while 25% added only about half of their twitch force to the twitch force of the nerve-activated units. "Nonadditive" units had significantly weaker twitch tensions than the units which added linearly. Lengthening or shortening the whole muscle, from maximal isometric settings, reduced whole muscle twitch tension as well as muscle unit tension. Injury to the lateral rectus muscle did not significantly alter whole muscle tension. These findings suggest that the known serial and branching arrangement of these muscle fibers, as well as the complex interfiber matrix, may help explain the force reduction in some muscle units and the whole muscle's resistance to insult.

Expression of the extracellular matrix protein tenascin in malignant and benign ovarian tumours

The extracellular matrix protein tenascin (TN) is overexpressed in a number of solid tumours. Thi however, is the first study to examine TN expression in ovarian tumours. TN protein was examined in froze sections of 50 human ovarian tumours by immunohistochemistry. Malignant and borderline tumours showed significantly greater incidence and intensity of stromal staining than benign tumours (P < 0.0001 and P = 0.038 respectively). Seven omental metastases were also examined and showed a strikingly similar protein distribution to their primary tumour counterparts. The expression pattern of different RNA isoforms, created by alternative splicing of the primary transcript, was identified using reverse transcription-polymerase chain reactions (RT-PCR). The smallest TN RNA splice variant (284 bp) was found in all tumours examined, while the appearance of larger molecular weight transcripts (approximately 490 and 556 bp), as major forms, was predominantly limited to malignant tumours, with 9/12 malignant tumours showing this pattern compared with 1/6 benign tumours. These data suggest that malignant ovarian tumours have increased expression of TN compared with benign tumours and this may be associated with induction of specific isoforms.

Extraocular motoneuron stimulation frequency effects on motor unit tension in cat

The contractile characteristics of 47 twitch and 3 nontwitch lateral rectus motor units in 11 cats were examined using two different stimulation paradigms derived from observed motoneuron firing frequencies in alert animals. The twitch units showed an average twitch tension (46.0 +/- 8.1 mg), contraction time (6.15 +/- 0.26 ms) and median fusion frequency (170 Hz) consistent with previous studies, kt value, defined as the slope of the relation between a series of constant frequency tetanic stimulation trains (lasting 200 ms) and tetanic tension, correlated with maximum tetanic tension (r = 0.984, p < 0.05). ktps value, defined as the slope of the relation between tetanic tension and a series of constant frequency stimulation trains (lasting 1975 ms) that immediately followed a 25-ms high-frequency burst (pulse/step paradigm), was similarly correlated (r = 0.853, p < 0.05) with maximum tetanic tension (x = 256.5 +/- 35.2 mg). ktps values were lower that kt values for each unit, but the units did not change their position in the numerical hierarchy. Eighty-four percent of the motor units produced different maximum tetanic tensions (x = 24 +/- 3%), when comparing pulse/step to constant frequency stimulation, but only 14% of those units produced a greater maximum tetanic tension during pulse/step stimulation. In contrast, 46% of the motor units contracted with more force during the step phase of the pulse/step paradigm than with constant frequency stimulation when the stimulation rate was below 120 Hz: 24% of the units contracted with less force. In addition, pulse/step stimulation frequency ranges above 120 Hz (step phase) were ineffective in increasing tension while higher frequencies continued to elicit tension increases during constant frequency stimulation. The impact of these tension variations on eye movement is discussed.