Positron emission tomography imaging for the assessment of mild traumatic brain injury and chronic traumatic encephalopathy: recent advances in radiotracers.

A chronic phase following repetitive mild traumatic brain injury can present as chronic traumatic encephalopathy in some cases, which requires a neuropathological examination to make a definitive diagnosis. Positron emission tomography (PET) is a molecular imaging modality that has high sensitivity for detecting even very small molecular changes, and can be used to quantitatively measure a range of molecular biological processes in the brain using different radioactive tracers. Functional changes have also been reported in patients with different forms of traumatic brain injury, especially mild traumatic brain injury and subsequent chronic traumatic encephalopathy. Thus, PET provides a novel approach for the further evaluation of mild traumatic brain injury at molecular levels. In this review, we discuss the recent advances in PET imaging with different radiotracers, including radioligands for PET imaging of glucose metabolism, tau, amyloid-beta, γ-aminobutyric acid type A receptors, and neuroinflammation, in the identification of altered neurological function. These novel radiolabeled ligands are likely to have widespread clinical application, and may be helpful for the treatment of mild traumatic brain injury. Moreover, PET functional imaging with different ligands can be used in the future to perform large-scale and sequential studies exploring the time-dependent changes that occur in mild traumatic brain injury.

[Corrigendum] Involvement of endothelial nitric oxide synthase pathway in IGF­1 protects endothelial progenitor cells against injury from oxidized LDLs.

Subsequently to the publication of this article, the authors have realized that the name of the first author was spelt incorrectly: The name was spelt as 'Hao­jing Wen', whereas the name should have been presented as 'Jing­wen Hao. The name as it should have appeared in the author list is featured above. The authors regret that this this error was not corrected prior to the publication of the above article, and apologize to the author in question and to the readership for any inconvenience caused.[the original article was published in Molecular Medicine Reports 19: 660­666, 2019; DOI:10.3892/mmr.2018.9633].

Involvement of endothelial nitric oxide synthase pathway in IGF­1 protects endothelial progenitor cells against injury from oxidized LDLs.

A high level of oxidized low­density lipoproteins (oxLDLs) is an independent risk factor for cardiovascular disease. The aim of the present study was to investigate whether insulin­like growth factor­1 (IGF­1) protected endothelial progenitor cells (EPCs) from injury caused by ox­LDLs, and whether the endothelial nitric oxide synthase (eNOS)/nitric oxide (NO) pathway was involved in this process. EPCs were isolated from human peripheral blood and characterized. In order to evaluate the effect of IGF­1 on EPCs, cells were incubated with ox­LDLs (100 mg/ml) for 24 h to induce a model of EPC dysfunction in vitro, which demonstrated a decrease in the number of EPCs, concomitant with increased apoptosis and decreased proliferation rates. IGF­1 dose­dependently increased the number of EPCs. Concurrently, IGF­1 decreased the levels of apoptosis of EPCs and improved EPCs proliferation following ox­LDLs challenge. In addition, IGF­1 significantly increased NO levels in ox­LDLs­treated EPCs, accompanied by an upregulation in eNOS expression. The protective effects of IGF­1 on EPCs and NO production were abolished by L­NAME, a specific eNOS inhibitor. These results suggested that IGF­1 protects EPCs from dysfunction induced by oxLDLs through a mechanism involving the eNOS/NO pathway.

Ectopic pregnancy in the liver incidentally diagnosed by imaging: A case report.

The present report describes the case of a 31-year-old woman diagnosed with an ectopic pregnancy in the liver. The patient presented with amenorrhea for 40 days and abdominal distention for 27 days. A liver mass had been detected 6 days prior to presentation. Using ultrasound (US), a hyperechoic mass with a fluid sonolucent area was detected in the right hepatic lobe. Examination by computed tomography (CT) revealed the presence of a mass in the right hepatic lobe with a slightly low-density peripheral region and an oval central portion of lower density in the plain scan; the enhanced scan revealed a significantly enhanced peripheral region and a non-enhanced central portion. 18F-fluodeoxyglucose (FDG) positron emission tomography (PET)-CT showed a mass in the right hepatic lobe with an increased intake of FDG in the peripheral region (maximum standard uptake value, 5.7) and a non-increased intake of FDG in the central portion. The patient was then subjected to hysteroscopy and laparoscopy. Histopathologically, the mass was an ectopic pregnancy. The patient recovered following the surgery. In conclusion, a timely diagnosis of ectopic pregnancy was made for a 31-year-old women with an ectopic pregnancy in the liver on the basis of US, CT and PET-CT imaging results, which enabled surgery to be undertaken prior to any serious consequences. These observations may be helpful for the diagnosis of similar cases in the future.

Pattern transitions of oil-water two-phase flow with low water content in rectangular horizontal pipes probed by terahertz spectrum.

The flow-pattern transition has been a challenging problem in two-phase flow system. We propose the terahertz time-domain spectroscopy (THz-TDS) to investigate the behavior underlying oil-water flow in rectangular horizontal pipes. The low water content (0.03-2.3%) in oil-water flow can be measured accurately and reliably from the relationship between THz peak amplitude and water volume fraction. In addition, we obtain the flow pattern transition boundaries in terms of flow rates. The critical flow rate Qc of the flow pattern transitions decreases from 0.32 m3 h to 0.18 m3 h when the corresponding water content increases from 0.03% to 2.3%. These properties render THz-TDS particularly powerful technology for investigating a horizontal oil-water two-phase flow system.

VEGF(165) expressing bone marrow mesenchymal stem cells differentiate into hepatocytes under HGF and EGF induction in vitro.

A short half-life and low levels of growth factors in an injured microenvironment necessitates the sustainable delivery of growth factors and stem cells to augment the regeneration of injured tissues. Our aim was to investigate the ability of VEGF(165) expressing bone marrow mesenchymal stem cells (BMMSCs) to differentiate into hepatocytes when cultured with hepatocyte growth factor (HGF) and epidermal growth factor (EGF) in vitro. We isolated, cultured and identified rabbit BMMSCs, then electroporated the BMMSCs with VEGF(165)-pCMV6-AC-GFP plasmid. G418 was used to select transfected cells and the efficiency was up to 70%. The groups were then divided as follows: Group A was electroporated with pCMV6-AC-GFP plasmid + HGF + EGF and Group B was electroporated with VEGF(165)-pCMV6-AC-GFP plasmid +HGF + EGF. After 14 days, BMMSCs were induced into short spindle and polygonal cells. Alpha-fetoprotein (AFP) was positive and albumin (ALB) was negative in Group A, while both AFP and ALB were positive in group B on day 10. AFP and ALB in both groups were positive on day 20, but the quantity of AFP in group B decreased with prolonged time and was about 43.5% less than group A. The quantity of the ALB gene was increased with prolonged time in both groups. However, there was no significant difference between group A and B on day 10 and 20. Our results demonstrated that VEGF(165)-pCMV6-AC-GFP plasmid modified BMMSCs still had the ability to differentiate into hepatocytes. The VEGF(165) gene promoted BMMSCs to differentiate into hepatocyte-like cells under the induction of HGF and EGF, and reduced the differentiation time. These results have implications for cell therapies.