Stem cells from human extracted deciduous teeth expanded in foetal bovine and human sera express different paracrine factors after exposure to freshly prepared human serum

Background: The response of stem cells to paracrine factors within the host’s body plays an important role in the regeneration process after transplantation. The aim of this study was to determine the viability and paracrine factor profile of stem cells from human extracted deciduous teeth (SHED) pre-cultivated in media supplemented with either foetal bovine serum (FBS) or pooled human serum (pHS) in the presence of individual human sera (iHS). Methods: SHED (n=3) from passage 4 were expanded in FBS (FBS-SHED) or pHS (pHS-SHED) supplemented media until passage 7. During expansion, the proliferation of SHED was determined. Cells at passage 7 were further expanded in human serum from four individual donors (iHS) for 120 hours followed by assessment of cell viability and profiling of the secreted paracrine factors. Results: Proliferation of SHED was significantly higher (p<0.05) in pHS supplemented media compared to FBS supplemented media. pHS-SHED also maintained their higher proliferation rate compared to FBS-SHED in the presence of iHS. In iHS supplemented media, FBS-SHED expressed significantly higher levels of SDF-1A (p<0.05) after 24 hours compared to pHS-SHED. Similar results were found for HGF (p<0.01), LIF (p<0.05), PDGF-BB (p<0.05), SDF-1A (p<0.01), and IL-10 (p<0.05) when cell culture supernatants from FBS-SHED was profiled 120 hours post-incubation. Conclusion: SHED expanded in pHS instead of FBS have higher proliferative capacity and show an altered secretion profile. Further studies are needed to determine whether these differences could result in better engraftment and regeneration following transplantation

Different isolation methods alter the gene expression profiling of adipose derived stem cells

Human adipose stem cells (ASCs) has been in the limelight since its discovery as a suitable source of mesenchymal stem cells (MSCs) in regenerative medicine. Currently, two major techniques are used to isolate ASCs, namely liposuction and tissue biopsy. These two methods are relatively risk-free but the question as to which method could give a more efficient output remains unclear. Thus, this study was carried out to compare and contrast the output generated in regards to growth kinetics, differentiation capabilities in vitro, and gene expression profiling. It was found that ASCs from both isolation methods were comparable in terms of growth kinetics and tri-lineage differentiation. Furthermore, ASCs from both populations were reported as CD44+, CD73+, CD90+, CD166+, CD34-, CD45- and HLA-DR-. However, in regards to gene expression, a group of overlapping genes as well as distinct genes were observed. Distinct gene expressions indicated that ASCs (liposuction) has endoderm lineage propensity whereas ASCs (biopsy) has a tendency towards mesoderm/ectoderm lineage. This information suggests involvement in different functional activity in accordance to isolation method. In conclusion, future studies to better understand these gene functions should be carried out in order to contribute in the applicability of each respective cells in regenerative therapy

Differential expression of basal microRNAs' patterns in human dental pulp stem cells

MicroRNAs (miRNAs) are small non-coding RNAs that regulate translation of mRNA into protein and play a crucial role for almost all biological activities. However, the identification of miRNAs from mesenchymal stem cells (MSCs), especially from dental pulp, is poorly understood. In this study, dental pulp stem cells (DPSCs) were characterized in terms of their proliferation and differentiation capacity. Furthermore, 104 known mature miRNAs were profiled by using real-time PCR. Notably, we observed 19 up-regulated miRNAs and 29 significantly down-regulated miRNAs in DPSCs in comparison with bone marrow MSCs (BM-MSCs). The 19 up-regulated miRNAs were subjected to ingenuity analysis, which were composed into 25 functional networks. We have chosen top 2 functional networks, which comprised 10 miRNA (hsa-miR-516a-3p, hsa-miR-125b-1-3p, hsa-miR-221-5p, hsa-miR-7, hsa-miR-584-5p, hsa-miR-190a, hsa-miR-106a-5p, hsa-mir-376a-5p, hsa-mir-377-5p and hsa-let-7f-2-3p). Prediction of target mRNAs and associated biological pathways regulated by each of this miRNA was carried out. We paid special attention to hsa-miR-516a-3p and hsa-miR-7-5p as these miRNAs were highly expressed upon validation with qRT-PCR analysis. We further proceeded with loss-of-function analysis with these miRNAs and we observed that hsa-miR-516a-3p knockdown induced a significant increase in the expression of WNT5A. Likewise, the knockdown of hsa-miR-7-5p increased the expression of EGFR. Nevertheless, further validation revealed the role of WNT5A as an indirect target of hsa-miR-516a-3p. These results provide new insights into the dynamic role of miRNA expression in DPSCs. In conclusion, using miRNA signatures in human as a prediction tool will enable us to elucidate the biological processes occurring in DPSCs

Correction to: Coronavirus (COVID-19) pandemic mediated changing trends in nuclear medicine education and training: time to change and scintillate (European Journal of Nuclear Medicine and Molecular Imaging, (2022), 49, 2, (427-435), 10.1007/s00259-021-05241-2)

The article Coronavirus (COVID-19) pandemic mediated changing trends in nuclear medicine education and training: time to change and scintillat

COVID-19 pandemic: guidance for nuclear medicine departments.

Coronaviruses are non-segmented, enveloped positive-sense ribonucleic acid viruses from the Coronaviridae family. There are six types of the coronavirus known to infect humans. Four of them cause mild respiratory symptoms, while two of them, the Middle East respiratory syndrome coronavirus (MERS) and the severe acute respiratory syndrome (SARS), have caused epidemics with high mortality rates. In December 2019, a new type of coronavirus 2019-nCoV/ SARS-CoV-2, causing COVID-19 disease, was extracted and identified from the lower respiratory tract samples of several patients in Wuhan, China. These patients presented with symptoms of severe pneumonia, including fever, fatigue, dry cough, and respiratory distress. The coronavirus disease 19 (COVID-19) is a highly transmittable and pathogenic viral infection. It is believed to be transmitted via respiratory droplets and fomites during close unprotected contact between an infector and an infectee. The coronaviruses mainly infect epithelial cells in the lung, but SARS-CoV-2 has been detected in respiratory, fecal, and blood specimens of patients infected with the virus. On February 3, 2020, the World Health Organization declared a public health emergency of international concern, and on March 11, declared COVID-19 a pandemic. The total number of confirmed cases, deaths associated with COVID19, and affected countries and territories continues to grow; detailed statistics can be found at the WHO–Coronavirus disease (COVID-19) Pandemic site or the John Hopkins Coronavirus Resource Centre. Health care providers around the world are facing challenging decisions. They are rapidly adjusting their standard operating procedures (SOPs) to cope with the pandemic cases and deliver their services. This is done in line with local guidance, resources available, and the advice of the World Health Organization (WHO) Minimum Requirements for infection prevention and control (IPC) programmes. This publication was prepared based on the systematic review of available literature on the subject and the contribution of a panel of international experts during the webinar entitled “Coronavirus disease (COVID-19) Pandemic: Challenges for the Nuclear Medicine Departments,” organized by the International Atomic Energy Agency (IAEA) and broadcasted live on Wednesday 25 March 2020. The objective of this guide is not to override any local guidance or national practice guidelines or rules, nor does it provide comprehensive advice on all aspects of nuclear medicine practice. It is solely intended as advice for nuclear medicine facilities during this time of adjustment and adaptation to the COVID-19 pandemic. We present suggested recommendations for nuclear medicine departments to follow, based on a typical patient’s “journey” through the department.http://link.springer.com/journal/259pm2020Nuclear Medicin