Reproducibility and optimization of in vivo human diffusion‐weighted MRS of the corpus callosum at 3T and 7T

Diffusion‐weighted MRS (DWS) of brain metabolites enables the study of cell‐specific alterations in tissue microstructure by probing the diffusion of intracellular metabolites. In particular, the diffusion properties of neuronal N‐acetylaspartate (NAA), typically co‐measured with N‐acetylaspartyl glutamate (NAAG) (NAA + NAAG = tNAA), have been shown to be sensitive to intraneuronal/axonal damage in pathologies such as stroke and multiple sclerosis. Lacking, so far, are empirical assessments of the reproducibility of DWS measures across time and subjects, as well as a systematic investigation of the optimal acquisition parameters for DWS experiments, both of which are sorely needed for clinical applications of the method. In this study, we acquired comprehensive single‐volume DWS datasets of the human corpus callosum at 3T and 7T. We investigated the inter‐ and intra‐subject variability of empirical and modeled diffusion properties of tNAA [D_avg(tNAA) and D_model(tNAA), respectively]. Subsequently, we used a jackknife‐like resampling approach to explore the variance of these properties in partial data subsets reflecting different total scan durations. The coefficients of variation (C_V) and repeatability coefficients (C_R) for D_avg(tNAA) and D_model(tNAA) were calculated for both 3T and 7T, with overall lower variability in the 7T results. Although this work is limited to the estimation of the diffusion properties in the corpus callosum, we show that a careful choice of diffusion‐weighting conditions at both field strengths allows the accurate measurement of tNAA diffusion properties in clinically relevant experimental time. Based on the resampling results, we suggest optimized acquisition schemes of 13‐min duration at 3T and 10‐min duration at 7T, whilst retaining low variability (C_V ≈ 8%) for the tNAA diffusion measures. Power calculations for the estimation of D_model(tNAA) and D_avg(tNAA) based on the suggested schemes show that less than 21 subjects per group are sufficient for the detection of a 10% effect between two groups in case–control studies. Copyright © 2015 John Wiley & Sons, Ltd.     

A study of variable origins of arteries in arm

A series of anomalous arterial supply of the arm and shoulder is presented. In these cases, the deep brachial artery arose from a common trunk with posterior circumflex humeral artery. In one case, the superior ulnar collateral artery and deep brachial artery originated from the posterior circumflex humeral artery. The common trunk or posterior circumflex humeral artery arose from the brachial artery at the level of the lower border of the teres major (at the origin of the brachial artery). A possible ontogenetic explanation is provided for this situation. Awareness of the variations of arteries of the arm or shoulder is important for angiographers and the surgeon who operates in this region. Preliminary part of this study was presented at the 1st Joint Meeting of EACA (European Association of Clinical Anatomy), AACA (American Association of Clinical Anatomists), Graz, Austria, 7–11 July, 2003.     

Human splenic polymorphonuclear myeloid-derived suppressor cells (PMN-MDSC) are strategically located immune regulatory cells in cancer

In contrast to the mouse, functional assets of polymorphonuclear myeloid-derived suppressor cells (PMN-MDSC) in the human spleen remain to be better elucidated. Here, we report that the spleen in gastric and pancreatic cancer adopts an immune regulatory character, harbors excessive amount of PMN-MDSC, and anatomically enables their interaction with T cells. Compared to the peripheral blood, the spleen from cancer patients contained significantly higher levels of low-density PMN-MDSC, but not early-stage MDSC (e-MDSC) and monocytic-MDSC (M-MDSC). Low-density fraction of polymorphonuclear (PMN) cells was enriched in immature myeloid cells and displayed higher levels of CD10, CD16, and ROS than their blood-derived counterparts. They were also positive for PD-L1, LOX-1, and pSTAT3. The white pulp and periarteriolar lymphoid sheath (PALS) were strategically surrounded by PMN cells that were in contact with T cells. Unlike those from the blood, both low-density and normal-density PMN cells from the human spleen suppressed T cell proliferation and IFN-γ production. Independent of clinical grade, high PMN-MDSC percentages were associated with decreased survival in gastric cancer. In summary, our results outline the immune regulatory role of the spleen in cancer where neutrophils acquire MDSC functions and feasibly interact with T cells.     

Assessment of the Quality and Reliability of Intragastric Balloon Videos on YouTube

Obesity Surgery - There is no mechanism to control the accuracy and quality of videos on YouTube. However, it is essential to evaluate the quality of videos on YouTube to prevent patients from...     

Failure of therapeutic vaccination using hepatitis B surface antigen vaccine in the immunotolerant phase of children with chronic hepatitis B infection

AIM: The aim of this study was to investigate the efficacy of specific hepatitis B virus (HBV) vaccination as active immunotherapy in treating chronic hepatitis B (CHB) infection during the immune-tolerant phase in children with normal aminotransferase levels and high viral load. METHODS: Fifty-one immunotolerant patients were randomly and prospectively recruited into two groups. Group 1 included 23 patients that were vaccinated with three standard injections of the GenHevac B vaccine in the deltoid or quadricep muscle, initially, and at 30 days and 60 days, for specific immunization. Group 2 contained 28 patients who did not receive any medication or vaccination and were recruited as the control group. Post-vaccination evaluation was performed at 6 months from the first injection and at the end of the 12th month by serological and virological analyses. A response criterion to therapy was defined as loss of HBV-DNA in serum and hepatitis B early antigen (HBeAg) seroconversion (loss of HBeAg, development of antibody to HBeAg (anti-HBe)). RESULTS: The mean alanine aminotransferase (ALT) value in group 1 at the beginning of the vaccination was 33.6 +/- 8.1 IU/L; this changed to 31.7 +/- 9.0 IU/L at 6 months after first injection and 29.2 +/- 7.1 IU/L at the end of 12 months (P > 0.05). In this group, mean HBV-DNA load at the starting point of the vaccination was 3,709 +/- 1,126 pg/mL; this value changed to 3,569 +/- 726 pg/mL at the sixth month and 3,295 +/- 832 pg/mL at the 12th month (P > 0.05). In group 2, the mean ALT values at the beginning of therapy, and at the 6th and 12th month were 32 +/- 8 IU/L, 31.8 +/- 8 IU/L, and 29.7 +/- 7 IU/L, respectively (P > 0.05), and the mean viral load of HBV-DNA values were 3,827 +/- 1,375 pg/mL, 3,498 +/- 886 pg/mL, and 3,059 +/- 731 pg/mL, respectively (P > 0.05). The load of HBV DNA of all patients in both groups was greater than 2,000 pg/mL. There was no statistically significant difference in the mean ALT values and mean viral load of HBV DNA (P > 0.05) between group 1 and group 2 at the end of the 6th and 12th months. Except for one each patient in each group, hepatitis B surface antigen (HBsAg) and HBeAg clearance or antibody to HBsAg (anti-HBs) and anti-HBe seroconversion were not observed during the follow-up period (P > 0.05). CONCLUSION: In this study, comparison of vaccinated and unvaccinated groups of immunotolerant children with CHB infection showed no difference in the clearance of HBV DNA and seroconversion of HBeAg to anti-HBe. Different immunization protocols should be considered for future investigations in the immunotolerant phase of children with CHB infection.