Photoacoustic imaging (PAI) is a noninvasive, nonionizing modality based on the differences in light absorption of various biological tissues. PAI utilizes the endogenous contrast characteristics of traditional optical imaging, while benefiting from high spatial resolution of the ultrasound imaging. A PAI system was developed to reconstruct the two-dimensional cross section image and to visualize the cerebrovascular activities of mouse in vivo. The spatial resolution of the PAI system was determined to be 0.110 mm by a two-point-source phantom with the Rayleigh criterion. The potential applications of the system were clearly demonstrated by successfully mapping a traumatic lesion in the mouse brain cerebral cortex, by its ability to monitor physiological changes in the brain due to carotid ligation and drug stimulation, and two-dimensional sliced images of a traumatic mouse brain at different depths were also provided. Our experimental results indicate that PAI has the potential for studying of traumatic brain injury and physiological functions of the brain.

BackgroundTo identify changes in brain activation patterns in bipolar disorder (BD) and unipolar depression (UD) patients.Methodology/Principal FindingsResting-state fMRI scans of 16 healthy controls, 17 BD and 16 UD patients were obtained. T-test of normalized regional homogeneity (ReHo) was performed in a voxel-by-voxel manner. A combined threshold of á = 0.05, minimum cluster volume of V = 10503 mm3 (389 voxels) were used to determine ReHo differences between groups. In UD group, fMRI revealed ReHo increases in the left middle occipital lobe, right inferior parietal lobule, right precuneus and left convolution; and ReHo decreases in the left parahippocampalgyrus, right precentralgyrus, left postcentralgyrus, left precentralgyrus and left cingulated. In BD group, ReHo increases in the right insular cortex, left middle frontal gyrus, left precuneus, left occipital lobe, left parietal, left superior frontal gyrus and left thalamus; and ReHo decreases in the right anterior lobe of cerebellum, pons, right precentralgyrus, left postcentralgyrus, left inferior frontal gyrus, and right cingulate. There were some overlaps in ReHo profiles between UD and BD groups, but a marked difference was seen in the thalamus of BD.Conclusions/SignificanceThe resting-state fMRI and ReHo mapping are a promising tool to assist the detection of functional deficits and distinguish clinical and pathophysiological signs of BD and UD.

Background information. Cadmium (Cd) is a highly toxic heavy metal that causes changes in plant metabolism through inhibiting photosynthesis and respiration. The effects of Cd on the morphology and function of the chloroplast and mitochondria, as well as on the production and localization of ROS (reactive oxygen species), were studied at the single-cell level in Arabidopsis.Results. The present study showed that the morphology of chloroplasts changed after Cd treatment, and the photochemical efficiency dramatically declined prior to obvious morphological distortion in the chloroplasts. A quick burst of ROS was detected after Cd treatment. The ROS appeared first in the mitochondria and subsequently in the chloroplast. Simultaneously, the mitochondria clumped irregularly around the chloroplasts or aggregated in the cytoplasm, and the movement of mitochondria was concomitantly blocked. Furthermore, the production of ROS was decreased after pre-treatment with ascorbic acid or catalase, which prevented inhibition of photosynthesis, organelle changes and subsequent protoplast death. Our results suggest that the distribution and mobility of mitochondria, the morphology of chloroplasts and the accumulation of ROS play important roles in Cd-induced cell death. The results are in good agreement with previous reports of many types of apoptotic-like cell death.Conclusion. The changes in the distribution and mobility of mitochondria, and morphology of chloroplasts, as well as the accumulation of ROS, play important roles in Cd-induced cell death.

E2Fs are a family of pivotal transcription factors. Accumulative evidence indicates that aberrant expression or activation of E2Fs is a common phenomenon in malignances, and significant associations have been noted between E2Fs and tumorigenesis or progression in a wide range of cancers. However, the expression patterns and exact roles of each E2F contributing to tumorigenesis and progression of ovarian cancer (OC) have not yet been elucidated. In this study, we investigated the distinct expression and prognostic value of E2Fs in patients with OC by analyzing a series of databases, including ONCOMINE, GEPIA, cBioPortal, Metascape, and Kaplan–Meier plotter. The mRNA expression levels of E2F1/3/5/8 were found to be significantly upregulated in patients with OC and were obviously associated with tumor stage for OC. Aberrant expression of E2F2/5/7/8 was found to be associated with the clinical outcomes of patients with OC. These results suggest that E2F2/5/8 might serve as potential prognostic biomarkers and targets for OC. However, future studies are required to validate our findings and promote the clinical utility of E2Fs in OC.

A fast thermoacoustic computed tomography system with a multielement linear transducer array was developed to image biological tissues with circular scanning. The spatial resolution of the imaging system and the spectra of the thermoacoustic signals were analyzed. A modified integration backprojection algorithm using velocity potential was employed to recover the direct energy deposition distribution, signal processing methods, and reconstruction algorithms were validated by imaging a phantom. The differences of the microwave-frequency dielectric properties between malignant and normal adipose-dominated tissues in the breast are considerable, and the absorption contrast can reach as large as 6:1 at 1.2 GHz. An experiment of human breast tissue with a tumor was performed with this system; the thermoacoustic images reconstructed by a limited-field-filtered backprojection algorithm and a modified integration backprojection algorithm were also compared with a mammogram. Our results show that the system can provide a rapid and noninvasive approach for high-contrast breast cancer imaging.

BackgroundQuantitative analyses of circulating cell-free DNA (cfDNA) are potential methods for the detection of ovarian cancer. Many studies have evaluated these approaches, but the results were too inconsistent to be conclusive. This study is the first to systematically evaluate the accuracy of circulating cfDNA for the diagnosis of ovarian cancer by conducting meta-analysis.MethodsWe searched PubMed, Embase, Cochrane Library and the Chinese National Knowledge Infrastructure (CNKI) databases systematically for relevant literatures up to December 10, 2015. All analyses were conducted using Meta-DiSc1.4 and Stata 12.0 software. Sensitivity, specificity and other measures of accuracy of circulating cfDNA for the diagnosis of ovarian cancer were pooled. Meta-regression was performed to identify the sources of heterogeneity.ResultsThis meta-analysis included a total of 9 studies, including 462 ovarian cancer patients and 407 controls. The summary estimates for quantitative analysis of circulating cfDNA in ovarian cancer screen were as follows: sensitivity, 0.70 (95% confidence interval (CI), 0.65–0.74); specificity, 0.90 (95% CI, 0.87–0.93); positive likelihood ratio, 6.60 (95% CI, 3.90–11.17); negative likelihood ratio, 0.34 (95% CI, 0.25–0.47); diagnostic odds ratio, 26.05 (95% CI, 14.67–46.26); and area under the curve, 0.89 (95% CI, 0.83–0.95), respectively. There was no statistical significance for the evaluation of publication bias.ConclusionsCurrent evidence suggests that quantitative analysis of cfDNA has unsatisfactory sensitivity but acceptable specificity for the diagnosis of ovarian cancer. Further large-scale prospective studies are required to validate the potential applicability of using circulating cfDNA alone or in combination with conventional markers as diagnostic biomarker for ovarian cancer and explore potential factors that may influence the accuracy of ovarian cancer diagnosis.

In an animal model, IVPAT allowed characterization of spatial and quantitative features of lipid-rich plaques.

Current imaging modalities face challenges in clinical applications due to limitations in resolution or contrast. Microwave-induced thermoacoustic imaging may provide a complementary modality for medical imaging, particularly for detecting foreign objects due to their different absorption of electromagnetic radiation at specific frequencies. A thermoacoustic tomography system with a multielement linear transducer array was developed and used to detect foreign objects in tissue. Radiography and thermoacoustic images of objects with different electromagnetic properties, including glass, sand, and iron, were compared. The authors' results demonstrate that thermoacoustic imaging has the potential to become a fast method for surgical localization of occult foreign objects.Significant progress has been made in the past several years in photoacoustic imaging. Microwave-induced thermoacoustic imaging which shares similar principles with photoacoustic imaging could potentially combine the advantages of microwave imaging and ultrasound imaging, to achieve high resolution and high absorption contrast. 1-5 Moreover, microwave-induced thermoacoustic imaging may provide wider medical applications because microwave radiation has higher tissue penetration depth than light and also has different contrast mechanisms. This feature of thermoacoustic imaging can be employed to detect occult foreign bodies in tissue.Thermoacoustic signal generation is a result of microwave-induced thermal effect. A small temperature surge can be produced when a biological tissue is irradiated by a microwave pulse of adequate energy. Subsequently, the heated structure thermally expands and contracts, becoming a source of acoustic wave. By detecting the sound wave and via signal reconstruction, thermoacoustic tomography (TAT) can be realized based on the differences in microwave absorption inside the target.Accidental invasion of foreign body into human tissue is rather frequent, especially in the case of a traumatic or iatrogenic injury. The common methods for locating foreign bodies present several drawbacks: Radiography is invasive and not ideal for detecting nonradiopaque substances such as glass and wood while magnetic resonance imaging (MRI) cannot function when metals are involved. And computed tomography and MRI are both cumbersome and expensive. TAT, which relies on microwave absorption, can help visualize electromagnetic differences in biological tissue. It has the potential to become an effective and low-cost biomedical imaging modality for disease diagnose. Furthermore, it could be used to recognize and locate foreign bodies rapidly and accurately. We have developed a fast photoacoustic imaging system using multielement linear transducer array. 6-9 A microwave-induced thermoacoustic tomography prototype was also designed and developed. 10 In this study, this system was applied to detect and localize occult foreign bodies in biological tissues. A phase-controlled focus technique is used to reduce data acquisition time and a limited-f...