One-Step Construction of 1,3,4-Oxadiazoles with Anticancer Activity from Tertiary Amines via a Sequential Copper(I)-Catalyzed Oxidative Ugi/aza-Wittig Reaction.

An unparalleled copper(I)-catalyzed synthesis of 1,3,4-oxadiazoles from tertiary amines in one step has been described. The one-pot reactions involving (N-isocyanimine)triphenylphosphorane, tertiary amines, and carboxylic acids resulted in the formation of 1,3,4-oxadiazoles in moderate to good yields through a consecutive oxidative Ugi/aza-Wittig reaction, enabling the direct functionalization of sp3 C-H bonds adjacent to the nitrogen atom. This method offered several notable advantages, including ligands-free, exceptional productivity and a high functional group tolerance. The preliminary biological evaluation demonstrated that compound 4f inhibited hepatoma cells efficiently, suggesting potentially broad applications of the approach for synthesis and medicinal chemistry.

Inhibition of cerebral ischemia/reperfusion injury-induced apoptosis: nicotiflorin and JAK2/STAT3 pathway.

Nicotiflorin is a flavonoid extracted from Carthamus tinctorius. Previous studies have shown its cerebral protective effect, but the mechanism is undefined. In this study, we aimed to determine whether nicotiflorin protects against cerebral ischemia/reperfusion injury-induced apoptosis through the JAK2/STAT3 pathway. The cerebral ischemia/reperfusion injury model was established by middle cerebral artery occlusion/reperfusion. Nicotiflorin (10 mg/kg) was administered by tail vein injection. Cell apoptosis in the ischemic cerebral cortex was examined by hematoxylin-eosin staining and terminal deoxynucleotidyl transferase dUTP nick end labeling assay. Bcl-2 and Bax expression levels in ischemic cerebral cortex were examined by immunohistochemial staining. Additionally, p-JAK2, p-STAT3, Bcl-2, Bax, and caspase-3 levels in ischemic cerebral cortex were examined by western blot assay. Nicotiflorin altered the shape and structure of injured neurons, decreased the number of apoptotic cells, down-regulates expression of p-JAK2, p-STAT3, caspase-3, and Bax, decreased Bax immunoredactivity, and increased Bcl-2 protein expression and immunoreactivity. These results suggest that nicotiflorin protects against cerebral ischemia/reperfusion injury-induced apoptosis via the JAK2/STAT3 pathway.

[Analysis of Spatio-temporal Distribution and Variation Characteristics of Aerosol Optical Depth over the Northwest of China by MODIS C6 Product].

This work compared the collection 6 MODIS aerosol optical depth products with sun photometer data from AERONET, and evaluated the applicability of C6 merged data in the northwest of China. The spatio-temporal variation characteristics and influencing factors of AOD over northwest of China were analyzed by MODIS/AQUA C6 MYD08-M3 products from 2006 to 2015, and the results showed that Southern Xinjiang and Guanzhong region of Shanxi province had relatively high AOD, whereas the south of Qinghai and Gansu province had low values; Junggar Basin was the incremental area of AOD for the first 5 years and second 5 years, whereas converse result existed in Qaidam Basin and Hetao area. Temporally, the yearly mean AOD ranged from 0.18 to 0.22, and the declined trend occurred in 2011, and the annual decrease rate was about 0.32%; Because of different intensity and frequency of dust weather, the south of Xinjiang showed a significant interannual variation characteristic; East of the northwest displayed an obviously declining trend from 2011 to 2015, and the yearly mean decrease was about 1.1%. The AOD in north of Xinjiang and Qinghai-Tibet remained stable. The seasonal changes of AOD among different areas over the northwest had the same trend, all gradually declined from spring to autumn, and increased in winter.

Transplantation of neural stem cells overexpressing glial cell line-derived neurotrophic factor enhances Akt and Erk1/2 signaling and neurogenesis in rats after stroke.

BACKGROUND: Our previous studies have indicated that the beneficial effects of grafting neural stem cells (NSCs) overexpressing glial cell line-derived neurotrophic factor (GDNF) in rats after stroke. However, the underlying mechanisms are highly debatable. In this study, we investigated whether neurogenesis, Akt, and extracellular signal-regulated kinase 1/2 (Erk1/2) signaling were involved in this process. METHODS: Transient ischemic stroke were induced by occluding middle cerebral artery for 2 hours and reperfusion. At 3 days after reperfusion, GDNF/NSCs, NSCs, and vehicle were administered. Immunohistochemical staining was used to evaluate neurogenesis by nestin antibody; phosphorylation of Akt and Erk1/2 was investigated by Western blotting analysis. RESULTS: Transplantation of GDNF/NSCs and NSCs significantly increased nestin-positive cells compared to control group (vehicle) from 1 to 7 weeks after reperfusion, and GDNF/NSCs showed stronger effect than NSCs at 2 and 3 weeks after reperfusion. Meanwhile, enhanced phosphorylation level of Erk1/2 was observed in the GDNF/NSCs and NSCs groups compared with control group, and phosphorylation level of Erk1/2 in GDNF/NSCs group was remarkably higher than that of NSCs group at any given time. In contrast, expression of mitogen-activated protein kinase phosphatase-1 (MKP-1), known as inhibitor of Erk1/2 signaling, was significantly decreased in the GDNF/NSCs and NSCs groups compared with the control group. Moreover, much enhanced and prolonged phosphorylation level of Akt of GDNF/NSCs group was detected compared with control and NSCs group. CONCLUSION: Grafting GDNF/NSCs enhances neurogenesis and activates Akt and Erk1/2 signaling, that may provide the potential for GDNF/NSCs in stroke treatment.

Ginsenoside Rb1 regulates the expressions of brain-derived neurotrophic factor and caspase-3 and induces neurogenesis in rats with experimental cerebral ischemia.

AIM OF THE STUDY: Recent studies have revealed that ginsenoside Rb1 (GRb1) is neuroprotective for cerebral ischemia. However, the mechanism underlying of this function is unclear. We assessed whether this neuroprotective effect of GRb1 was mediated by the levels of brain-derived neurotrophic factor (BDNF), by the levels of caspase-3 proteins and by induced neurogenesis in rats following transient cerebral ischemia or not. MATERIALS AND METHODS: Cerebral ischemia was prepared by a 2 h occlusion of the middle cerebral artery and reperfusion, followed by infusion of GRb1 (40 mg/kg) and saline (GRb1 and ischemia groups, respectively). All rats were sacrificed at 3 and 12 h, 1, 2, 3, 5, and 10 days after reperfusion. Normal and sham-operated rats were used in control group. Modified Neurological Severity Scores (mNSS) test and hematoxylin and eosin staining were respectively performed to evaluate neurological function and histological feature. Immunohistochemistry was used to identify intrinsic neurogenesis by nestin antibody. Western blotting was used to detect BDNF and caspase-3 protein content. RESULTS: GRb1 infusion after cerebral ischemia significantly promoted recoveries of neurological functions at 3 and 5 days after reperfusion compared to ischemic rats. The number of nestin-positive cells was apparently increased after GRb1 infusion compared to ischemia rats at given time. Moreover, BDNF was significantly increased in GRb1-treated rats compared to ischemia rats at different time points. In contrast, GRb1 infusion after the onset of reperfusion, caspase-3 at a given time was significantly reduced compared to ischemia rats, but still significantly increased compared to control rats. CONCLUSIONS: Promotion of the neurogenesis and regulation of the expressions of BDNF and caspase-3 may be involved in GRb1-induced neuroprotection against cerebral ischemia.

[Analysis of the correlation between non-invasive hemodynamic monitor and cardiac echocardiography on the evaluation of cardiac function].

OBJECTIVE: To explore the possibility of clinical evaluation of cardiac function by CHM T3002 non-invasive hemodynamic monitor. METHODS: A total of 26 patients admitted to Zhongshan Hospital in Shanghai were enrolled, including 11 cardiac insufficiency patients and 15 control. Each subject was tested by non-invasive cardiac hemodynamic monitor immediately after echocardiography. Linear regression analysis and Bland-Altman consistency analysis were used in the analysis of relevance and consistency between two different methods. RESULTS: Linear correlation was shown on LVEF, SV, SVI, CO, CI, EDV, LVET and PEP/LVET, but not on PEP, between the two methods. Moreover, the consistency of the two methods was highly confirmed on LVEF and LVET, less on SV, SVI, CO, CI and EDV, while awfully weak on PEP and PEP/LVET. CONCLUSION: CHM T3002 non-invasive hemodynamic monitor may be useful in assessing patients' cardiac function, however, it can not replace cardiac echocardiography.

[Effects of Ginsenoside RB1 on neural cell apoptosis and expressions of Bcl-2 and Bax in rats following subjected to cerebral ischemia-reperfusion].

OBJECTIVE: To observe the effects of Ginsenoside Rb1 (GRb1) on neuronal cell apoptosis and the expressions of Bcl-2 and Bax in rats after cerebral ischemia-reperfusion so as to investigate the neuroprotective mechanism of GRb1. METHDOS: The model of cerebral ischemia-reperfusion was established by occluding rat middle cerebral artery for 2 h. The rats were randomly divided into two groups: ischemia-reperfusion group (I/R group) and GRb1 treat group (GRb1 group). GRb1 (40 mg/kg, i.p.) was administered immediately to rats after the onset of reperfusion. Two groups were further subdivided 7 subgroups according to various reperfusion time (3 h, 12 h, 1 d, 2 d, 3 d, 5 d and 10 d, n=4 per time point). HE staining was used to observe histological features. TUNEL and immunohistochemical method were used to analyze the cell apoptosis and expressions of Bcl-2 and Bax, respectively. RESULTS: Compared with I/R group, GRb1 reduced pathological changes, and decreased the number of apoptotic neural cells (P<0.05 on 12 h, 1 d, 2 d and 3 d) and up-regulated the number of Bcl-2 positive cells (P<0.05 on 12 h, 1 d, 3 d, 5 d and 10 d), and meanwhile down-regulated the number of Bax positive cells (P<0.05 on 3 h, 12 h, 1 d, 2 d, 3 d, 5 d and 10 d) in the ipsilateral hemisphere. CONCLUSION: The neuroprotective effect of GRb1 on cerebral ischemia-reperfusion injury is related to inhibit neuronal apoptosis and to up-regulate the expression of Bcl-2 with down-regulating the expression of Bax.