Correlation between breast cancer and background parenchymal uptake on 18F-fluorodeoxyglucose positron emission tomography.

PURPOSE: This study aimed to investigate differences in background parenchymal uptake (BPU) between patients with and without breast cancer using 18F-fluorodeoxyglucose positron emission tomography. METHODS: Female patients (n = 130, 62.9 ± 12.7 years) with newly diagnosed breast cancer and 50 healthy participants (59.6 ± 13.3 years) without breast cancer were retrospectively included. BPU was evaluated using the maximum standardized uptake value. Data on participant age, body mass index, blood glucose level, and menopausal status were collected from medical records. Breast density was evaluated using mammography. Logistic regression analysis and receiver operating characteristic curves were used to examine the correlation between breast cancer and various characteristic factors, including BPU. RESULTS: The BPU of patients with breast cancer was significantly higher than that of controls (P < 0.001). The results of logistic regression analysis regarding the presence of breast cancer demonstrated that BPU and menopausal status showed higher odds ratios of 13.6 and 4.25, respectively. The area under the receiver operating characteristic curve for BPU was 0.751. CONCLUSIONS: Patients with breast cancer showed higher 18F-fluorodeoxyglucose-BPU. Glucose metabolism of mammary glands may correlate with the development of breast cancer.

Impact of patient characteristic factors on the dynamics of liver glucose metabolism: Evaluation of multiparametric imaging with dynamic whole-body 18 F-fluorodeoxyglucose-positron emission tomography.

AIMS: To assess the impact of various patient characteristics on the dynamics of liver glucose metabolism using automated multiparametric imaging with whole-body dynamic 18 F-fluorodeoxyglucose (FDG)-positron emission tomography (PET). MATERIALS AND METHODS: We retrospectively enrolled 540 patients who underwent whole-body dynamic FDG-PET. Three quantitative indices representing hepatic glucose metabolism [mean standardized uptake value normalized by lean body mass (SULmean), metabolic glucose rate (kinetic index) and distribution volume (DV)] were measured from multiparametric PET images produced automatically based on the Patlak plot model. Patient characteristics including age, sex, body mass index, fasting time, blood glucose level, and the presence of diabetes mellitus (DM) or hepatic steatosis (HS) were collected. We examined the correlations between the characteristic factors and three quantitative indices using multiple regression analysis. RESULTS: The success rate of kinetic analysis using multiparametric PET imaging was 93.3% (504/540). Hepatic SULmean was significantly correlated with age (p < .001), sex (p < .001) and blood glucose level (p = .002). DV was significantly correlated with age (p = .033), sex (p < .001), body mass index (p = .002), fasting time (p = .043) and the presence of HS (p = .002). The kinetic index was significantly correlated with age (p < .001) and sex (p = .004). In the comparison of the healthy, DM and HS groups, patients with DM had a significantly increased SULmean, whereas patients with HS had a significantly decreased DV. CONCLUSIONS: Our results showed that liver glucose metabolism was influenced by various patient characteristic factors. Multiparametric FDG-PET imaging can be used to analyse the kinetics of liver glucose metabolism in routine clinical practice.

Fully-automatic blood-typing chip exploiting bubbles for quick dilution and detection.

A compact, fully-automatic blood-typing test device is developed. The device conducts sequential processes of whole-blood dilution, homogenization, and reaction with reagents. The lab-on-a-chip device can detect the weakest reaction between red blood cells (RBCs) and reagents even without using optics such as a camera and detector. This high sensitivity is achieved by implementing 50-µm-thick reaction chambers in which a clear contrast between the RBC agglutinations and non-reacted RBCs can be obtained. The dilution and the homogenization are enhanced by injecting bubbles into the microchannel so that the test result can be obtained 5 min after the test start. With an assumption that the device will be used by medical staffs, the device is designed to require minimum operation for the users, namely, loading whole blood, starting pumps, and looking inside the reaction chambers by their eyes to observe the test result. As the device is applicable to the cross-matching test by mixing RBCs with serum instead of the reagents, it is expected that the device provides not only the quick blood-typing but also a safer and quicker blood transfusion in emergency rooms.

Concentration-adjustable micromixers using droplet injection into a microchannel.

A novel micromixing technique that exploits a thrust of droplets into the mixing interface is developed. The technique enhances the mixing by injecting immiscible droplets into a mixing channel and the methodology enables control of the mixing level simply by changing the droplet injection frequency. We experimentally characterize the mixing performance with various droplet injection frequencies, channel geometries, and diffusion coefficients. Consequently, it is revealed that the mixing level increases with the injection frequency, the droplet-diameter-to-channel-width ratio, and the diffusion coefficient. Moreover, the mixing level is found to be a linear function of the droplet volume fraction in the mixing section. The results suggest that the developed device can produce a large amount of sample solution whose concentration is arbitrary and precisely controllable with a simple and stable operation.

Low dependency of retrotransposition on the ORF1 protein of the zebrafish LINE, ZfL2-1.

The zebrafish long interspersed element (LINE), ZfL2-1, which belongs to the L2 clade, contains two open reading frames, ORF1 and ORF2. ORF1 encodes a protein containing a coiled-coil motif and an esterase domain, whereas ORF2 encodes a protein containing an endonuclease and a reverse transcriptase domain. To elucidate the functional significance of ORF1 in retrotransposition, we constructed many variants of ZfL2-1 and examined their retrotransposition ability. We concluded: 1) the ORF1 protein is not essential for ZfL2-1 retrotransposition in cultured cells; 2) the translation of ORF1 is required for the translation of ORF2; and 3) ORF2 translation probably occurs via suppression of the ORF1 stop codon, the efficiency of which is influenced by the context of the sequence juxtaposed to the 3' side of the stop codon. These results offer a new perspective on the evolution of the L2 clade LINEs.