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Cancer stem cells (CSCs) are a small subpopulation in cancer, have been proposed to be cancer-initiating cells, and have been shown to be responsible for chemotherapy resistance and cancer recurrence. The identification of CSC subpopulations inside a tumor presents a new understanding of cancer development because it implies that tumors can only be eradicated by targeting CSCs. Although advances in liver cancer detection and treatment have increased the possibility of curing the disease at early stages, unfortunately, most patients will relapse and succumb to their disease. Strategies aimed at efficiently targeting liver CSCs are becoming important for monitoring the progress of liver cancer therapy and for evaluating new therapeutic approaches. Herein, we provide a critical discussion of biological markers described in the literature regarding liver cancer stem cells and the potential of these markers to serve as therapeutic targets.

The Artemisia/Chenopodiaceae (A/C) ratio is assumed to be a useful index for reconstructing moisture changes in arid and semi-arid regions. Thorough modern pollen studies are still lacking to understand the reliability and limitation of A/C ratio as a moisture indicator, however. Here we review how well this ratio can be applied in arid and semi-arid China on the basis of new surface pollen data, previous data synthesis and other publications. Results indicate that variance in the A/C ratio can permit identification of modern vegetation types and that the A/C ratio generally has a positive relationship with annual precipitation. However, soil salinity, vegetation community composition, human activity and sample provenance (e.g. soil and lake sediments) will affect the values of the A/C ratio in different vegetation zones and therefore the A/C ratio is not comparable in different regions. We argue that the A/C ratio can only be used to reconstruct vegetation types and climate change in regions with precipitation <450–500 mm, and in steppe, steppe desert and desert areas. Careful studies should be undertaken to understand the modern pollen–vegetation–climate relationships in various regions before using the A/C ratio to interpret vegetation and climate.

Background:The study was carried out to examine the effect of selective α1 adrenoceptor agonist midodrine hydrochloride vs. β-adrenergic blockade metoprolol in the treatment of children with postural orthostatic tachycardia syndrome (POTS). Methods and Results:Fifty-three children with POTS were divided into group I (midodrine hydrochloride plus conventional therapy), group II (metoprolol plus conventional therapy) and group III (conventional therapy). Standing test was conducted for all participants. The cure rate, improvement rate, effective rate and score of symptoms were compared among the 3 groups. A Kaplan-Meier survivorship curve was used to describe the proportion of symptom-free cases during a long term follow-up. The cure rate and effective rate at the end of short term followup in group I were significantly higher than those of group II and group III (68.42% vs. 42.11% vs. 20.00%, P<0.05; 89.47% vs. 57.89% vs. 53.33%, P<0.05). After treatment, the symptom score in group I was significantly lower than group II and group III, respectively (1.1±2.2 vs. 2.8±2.4 vs. 3.7±2.0, P<0.05), and it also had significant difference between group II and group III (P<0.05). The symptom recurrent rate in group I was significantly lower than that of group II and group III, respectively (P<0.05), but it did not differ between group II and group III (P>0.05). Conclusions:Midodrine hydrochloride is effective in the treatment of children with POTS. (Circ J 2011; 75: 927 - 931)

OBJECTIVES: Although it is widely believed that China is facing a major shortage of pediatricians, the real situation of the current national status of pediatric human resources and their working conditions has not been evaluated to date. METHODS: We administered a survey to 54 214 hospitals from all 31 provinces in mainland China from 2015 to 2016. Hospital directors of all secondary and tertiary hospitals with pediatric services and a random sample (10%) of primary hospitals provided information on number of pediatricians and their educational levels, specialties, workloads, dropout rates, and other hospital characteristics. A data set of medical resources and socioeconomic information regarding each region (1997–2016) was constructed from the Chinese National Statistics Bureau. The Gini coefficient was used to describe the geographical distributions of pediatricians and hospitals. RESULTS: There were 135 524 pediatricians in China or ∼4 pediatricians per 10 000 children. Pediatricians’ average educational level was low, with ∼32% having only 3 years of junior college training after high school. The distribution of pediatricians was extremely skewed (Gini coefficient 0.61), and the imbalance of highly educated pediatricians was even more skewed (Gini coefficient 0.68). The dropout rate of pediatricians was 12.6%. Despite an increase in the Chinese government’s financial investment in health over the last decade, physicians have been burdened with a greater workload. CONCLUSIONS: Uneven development of the pediatric care system, inadequately trained pediatricians, low job satisfaction, and unmet demand for pediatric care are the major challenges facing China’s pediatric health care system.

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Bone marrow stromal cells (BMSCs, also broadly known as bone marrow-derived mesenchymal stem cells) are multipotent stem cells that have a self-renewal capacity and multilineage differentiation potential. Mechanical stretching plays a vital role in regulating the proliferation and differentiation of BMSCs. However, little is known about the effects of cyclic stretching on BMSC migration and invasion. In this study, using a custom-made cell-stretching device, we studied the effects of cyclic mechanical stretching on rat BMSC migration and invasion using a Transwell Boyden Chamber. The protein secretion of matrix metalloproteinase-2 (MMP-2) and matrix metalloproteinase-9 (MMP-9) was detected by gelatin zymography, and the activation of focal adhesion kinase (FAK) and extracellular signal regulated kinase1/2 (ERK1/2) was measured by western blot. We found that cyclic mechanical stretching with 10% amplitude at 1Hz frequency for 8h promotes BMSC migration, but reduces BMSC invasion. FAK and ERK1/2 signals were activated in BMSCs after exposure to cyclic stretching. In the presence of the FAK phosphorylation blocker PF573228 or the ERK1/2 phosphorylation blocker PD98059, the cyclic-stretch-promoted migration of BMSCs was completely suppressed. On the other hand, cyclic mechanical stretching reduced the secretion of MMP-2 and MMP-9 in BMSCs, and PF573228 suppressed the cyclic-stretch-reduced secretion of MMP-2 and MMP-9. The decrease of BMSC invasion induced by mechanical stretching is partially restored by PF573228 but remained unaffected by PD98059. Taken together, these data show that cyclic mechanical stretching promotes BMSC migration via the FAK-ERK1/2 signalling pathway, but reduces BMSC invasion by decreasing secretion of MMP-2 and MMP-9 via FAK, independent of the ERK1/2 signal.

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