No abstract

BACKGROUND: Secretome production by stem cells depends on their culture conditions such as oxygen concentration and the composition of the culture media. In this study, we investigated the secretion of neurotrophic growth factors of human umbilical cord mesenchymal stem cells (hUC-MSCs) in amino acid-rich culture medium and under hypoxic condition.METHODS: hUC-MSCs were cultured in normoxic and various hypoxic (1%, 5%, 10%) conditions in an amino acid-rich culture medium. The end-point parameters (cell proliferation and survival, cell morphology and growth factor secretion) were measured at 3 time-points (48 hours, 72 hours and 96 hours). ELISA-based methods were used for neurotrophic factors detection, including neurotrophic growth factor (NGF), vascular endothelial factor (VEGF), and brain-derived neurotrophic factor (BDNF).RESULTS: NGF secretion was not detectable at any time points both in normoxia and hypoxia. BDNF secretion under normoxia was induced at 48 h time point and reached the highest level at an average of 181.9±13.01 pg/mL at 96 hours, whereas hypoxia exposure to hUC-MSCs only induced the BDNF secretion at low level. VEGF secretion was barely detectable in normoxic condition. However, VEGF secretion reached the highest level at an average of 7707.55±2110.85 pg/mL in 5% hypoxia at 96 hours.CONCLUSION: Combination of amino acid-rich culture medium and hypoxia condition dramatically induced high VEGF secretion by hUC-MSCs, especially at 5% hypoxia, induced mild BDNF secretion and had no effect toward NGF secretion.KEYWORDS: human umbilical cord mesenchymal stem cells, neurotrophic growth factor, amino acid-rich, hypoxia

The Ministry of Health of Indonesia has established large-scale social restrictions (LSSR) to limit the transmis- sion of Covid-19, which inherently causes an increase in screen time levels and the physical activity level of students. This study aims to compare the level of screen time and physical activity before and during LSSR. This cross-sectional study was involved 206 medical students of the Atma Jaya School of Medicine and Health Sciences. Data were collected using a questionnaire and the International Physical Activity Questionnaire (IPAQ) – long form. A paired t-test, Wilcoxon signed-rank test, and McNemar test were used to compare the level of screen time and physical activity before and during LSSR. The mean screen time, sedentary time on weekday and weekend were significantly increased (Δ0.6, Δ1.7, Δ1.3 hours, respectively, all p<0.001), while total calorie of physical activity reduced (Δ-435, p<0.001). The number of students with higher screen time and sedentary time was also raised (Δ12.1%, Δ19.4%, Δ14.6%, respectively, all p<0.001), while the number of students with sufficient physical activity was significantly diminished (Δ-13.6%, p<0.001). There was a shift in the use of application types. The most significant change was Line usage, which had decreased by almost half (from 80 to 43). The pandemic situation greatly affected the students’ physical activity behaviour to be more sedentary and changed the use of application type.

Globally, there is an increasing prevalence of vitamin D deficiency, including in Southeast Asia, which ranges from 6% to 70%. Vitamin D plays an important role in calcium metabolism and bone health. Melanin is one factor that contributes to vitamin D deficiency. It has photoprotective properties that inhibit vitamin D synthesis, but the mechanism has not been fully understood. To determine the mechanism of the association between melanin and vitamin D, this systematic review was conducted on 11 articles, including cross-sectional studies, cohort studies, and randomised controlled trials published from 2010 to 2020. The search included Pubmed, EBSCO, and Proquest databases, and data were synthesised from 11 studies. This critical review found nine of the 11 studies reported a significant association between melanin and vitamin D, while two reported non-significant results. Of the nine significant studies, eight reported that people with higher melanin have lower vitamin D levels, while one study suggested that melanin levels do not necessarily associate with lower vitamin D levels. In conclusion, the review establishes a significant association between melanin and vitamin D.

Background Many studies have reported the presence of Positive Regulatory/Su(var)3-9, Enhancer-of-zeste and Trithorax Domain 2 (PRDM2) downregulation in cancer. However, its potential as a diagnostic biomarker is still unclear. Hence, a systematic review and meta-analysis were conducted to address this issue. Introduction As of 2018, cancer has become the second leading cause of death worldwide. Thus, cancer control is exceptionally vital in reducing mortality. One such example is through early diagnosis of cancer using tumor biomarkers. Having a function as a tumor suppressor gene (TSG), PRDM2 has been linked with carcinogenesis in several solid tumor. This study aims to assess the relationship between PRDM2 downregulation and solid tumor, its relationship with clinicopathological data, and its potential as a diagnostic biomarker. This study also aims to evaluate the quality of the studies, data reliability and confidence in cumulative evidence. Materials & Methods A protocol of this study is registered at the International Prospective Register of Systematic Reviews (PROSPERO) with the following registration number: CRD42019132156. PRISMA was used as a guideline to conduct this review. A comprehensive electronic search was performed from inception to June 2019 in Pubmed, Cochrane Library, ProQuest, EBSCO and ScienceDirect. Studies were screened and included studies were identified based on the criteria made. Finally, data synthesis and quality assessment were conducted. Results There is a significant relationship between PRDM2 downregulation with solid tumor (RR 4.29, 95% CI [2.58–7.13], P < 0.00001). The overall sensitivity and specificity of PRDM2 downregulation in solid tumors is 84% (95% CI [39–98%]) and 86% (95% CI [71–94%]), respectively. There is a low risk of bias for the studies used. TSA results suggested the presence of marked imprecision. The overall quality of evidence for this study is very low. Discussion We present the first meta-analysis that investigated the potential of PRDM2 downregulation as a diagnostic biomarker in solid tumor. In line with previous studies, our results demonstrated that PRDM2 downregulation occurs in solid tumor. A major source of limitation in this study is the small number of studies. Conclusions Our review suggested that PRDM2 is downregulated in solid tumor. The relationship between PRDM2 downregulation and clinicopathological data is still inconclusive. Although the sensitivity and specificity of PRDM2 downregulation are imprecise, its high values, in addition to the evidence that suggested PRDM2 downregulation in solid tumor, hinted that it might still have a potential to be used as a diagnostic biomarker. In order to further strengthen these findings, more research regarding PRDM2 in solid tumors are encouraged.