[Effects of Long-term Fertilization on Soil Nutrient Characteristics and Microbial Resource Restrictions in a Terrace on the Loess Plateau].

Long-term fertilization has an important effect on soil fertility and soil microbial activity. In order to explore the effects of long-term fertilization on soil extracellular enzyme activities and nutrient characteristics in a terrace on the Loess Plateau, we based our investigation on the long-term nutrient localization plot of Ansai Soil and Water Conservation Experimental Station, Chinese Academy of Sciences. We measured the soil physicochemical properties, microbial biomass, and extracellular enzyme activities of six fertilization treatments, which included no fertilization (CK); manure and nitrogen fertilization (MN); manure and phosphate fertilization (MP); manure, nitrogen, and phosphate fertilization (MNP); manure (M); and nitrogen and phosphate fertilization (NP). The results showed that all fertilization treatments significantly increased soil nutrient content and soil extracellular enzyme activities compared with that in CK. Correlation analysis showed that extracellular enzyme activity and soil physicochemical properties had an extremely significant correlation. The redundancy analysis indicated that soil nutrient and soil microbial biomass could explain 79.66% and 74.87% of the variation in soil extracellular enzyme activity and its stoichiometric ratio, respectively. Thus, the effects of fertilization on soil fertility were primarily through influencing soil extracellular enzyme activities indirectly. M, MN, MP, and MNP significantly improved soil organic carbon (SOC); soil total nitrogen (STN); and carbon (C), nitrogen (N), and phosphorus (P) source enzyme content; however, MNP changed the soil pH, which had an inhibitory effect on microbial activities. Vector analysis showed that the microbial communities of all treatments were in the condition of P limitation. Although MNP could alleviate the extent of P limitation, there was no significant difference between M and MP. Our study indicated that long-term application of manure[7500 kg·(hm2·a)-1]could meet the nutrient requirements of dryland crop growth, and long-term application of manure combined with phosphorus fertilization could alleviate the resource constraints faced by microorganisms. Consequently, our results provide a new insight into improving regional nitrogen excess.

Electroacupuncture exerts neuroprotective effects on ischemia/reperfusion injury in JNK knockout mice: the underlying mechanism.

Simple regulation of c-Jun N-terminal kinase (JNK) or p38 mitogen-activated protein kinase (MAPK) pathways is not enough to trigger cell apoptosis. However, activation of the stress activated pathway (JNK/p38 MAPK) together with inhibition of the growth factor activated extracellular signal-regulated kinase (ERK) pathway can promote cell apoptosis. We hypothesized that inhibition of the JNK or p38 pro-apoptotic pathway and activating the ERK pathway could be the mechanism of anti-apoptosis following cerebral ischemia/reperfusion injury. To investigate the mechanism of the protective effect of electroacupuncture on cerebral ischemia/reperfusion injury in JNK knockout mice, mouse models of cerebral ischemia/reperfusion injury were established by Longa's method. Electroacupuncture was conducted at acupoints Chize (LU5), Hegu (LI4), Sanyinjiao (SP6) and Zusanli (ST36) 1.5 hours after ischemia/reperfusion injury for 20 minutes, once a day. The neurological function was evaluated using neurological deficit scores. The expression of phospho-extracellular signal-regulated kinase (p-ERK) and phospho-p38 (p-p38) in JNK knockout mice was detected using double-labeling immunofluorescence and western blot assay. The mRNA expression of ERK and p38 was measured by quantitative real-time polymerase chain reaction. Electroacupuncture improved neurological function, increased the immunoreactivity and relative expression of p-ERK and reduced that of p-p38 in the cerebral cortex and hippocampus on the injured side. Electroacupuncture increased mRNA expression of ERK, but decreased that of p38 in the cerebral cortex and hippocampus on the injured side. In conclusion, electroacupuncture upregulated the protective ERK pathway and inhibited the pro-apoptotic p38 pathway, thereby exerting a neuroprotective effect and improving the neurological function in JNK knockout mice.

Electroacupuncture reduces apoptotic index and inhibits p38 mitogen-activated protein kinase signaling pathway in the hippocampus of rats with cerebral ischemia/reperfusion injury.

Electroacupuncture attenuates cerebral hypoxia and neuronal apoptosis induced by cerebral ischemia/reperfusion injury. To further identify the involved mechanisms, we assumed that electroacupuncture used to treat cerebral ischemia/reperfusion injury was associated with the p38 mitogen-activated protein kinase (MAPK) signaling pathway. We established rat models of cerebral ischemia/reperfusion injury using the modified Zea-Longa's method. At 30 minutes before model establishment, p38 MAPK blocker SB20358 was injected into the left lateral ventricles. At 1.5 hours after model establishment, electroacupuncture was administered at acupoints of Chize (LU5), Hegu (LI4), Zusanli (ST36), and Sanyinjiao (SP6) for 20 minutes in the affected side. Results showed that the combination of EA and SB20358 injection significantly decreased neurologic impairment scores, but no significant differences were determined among different interventional groups. Hematoxylin-eosin staining also showed reduced brain tissue injuries. Compared with the SB20358 group, the cells were regularly arranged, the structures were complete, and the number of viable neurons was higher in the SB20358 + electroacupuncture group. Terminal deoxynucleotidyl transferase (TdT)-mediated dUTP nick-end labeling assay showed a decreased apoptotic index in each group, with a significant decrease in the SB20358 + electroacupuncture group. Immunohistochemistry revealed reduced phosphorylated p38 expression at 3 days in the electroacupuncture group and SB20358 + electroacupuncture group compared with the ischemia/reperfusion group. There was no significant difference in phosphorylated p38 expression between the ischemia/reperfusion group and SB20358 group. These findings confirmed that the electroacupuncture effects on mitigating cerebral ischemia/reperfusion injury are possibly associated with the p38 MAPK signaling pathway. A time period of 3 days could promote the repair of ischemic cerebral nerves.

[Effect of Chinese medicine of nourishing kidney and clearing liver on intermittent hypoxia induced injury model of HUVECs through p38MAPK/NF-κB signaling pathway].

This study aims to explore the intervention effect of Chinese medicine of nourishing kidney and clearing liver on intermittent hypoxia(IH) induced injury model of HUVECs through p38MAPK/NF-κB signaling pathway in vitro. HUVECs injury model was induced by modified IH treatment. The effective components of Chinese medicine of nourishing kidney and clearing liver including isochteroside, aucubin and ligustrazine were used as intervention drugs. The optimal compatibility concentration of them was screened in vitro, and then the optimal compatibility concentration was selected as the intervention dose to observe the effect on p38MAPK/NF-κB signaling pathway in IH induced injury model of HUVECs. The results showed that isochnae, aucubin and ligustrazine had the best anti-inflammatory effect at concentration of 0.01 mg•L-1. NF-κB p65 and p-IκB in the nucleus in IH group were significantly higher than those in the normal control(N) group and the other groups. Immunofluorescence staining showed significant translocation of NF-κB p65 nucleus in IH group, and HUVECs adhesion capacity in IH group was increased significantly. As compared with IH group, the expression levels of p-p38MAPK, NF-κB p65 and p-IκB in p38MAPK inhibitor(INH) group and Chinese medicine of nourishing kidney and clearing liver(GDC) group were significantly decreased, and HUVECs adhesion capacity in INH group and GDC group was significantly inhibited as well. The optimal concentration of Chinese medicine of nourishing kidney and clearing liver can inhibit the phosphorylation of p38MAPK, and then inhibit the nuclear translocation and transcription function of NF-κB. This may be the mechanism of the protective effect of Chinese medicine on IH induced injury model of HUVECs.

Brain activation and inhibition after acupuncture at Taichong and Taixi: resting-state functional magnetic resonance imaging.

Acupuncture can induce changes in the brain. However, the majority of studies to date have focused on a single acupoint at a time. In the present study, we observed activity changes in the brains of healthy volunteers before and after acupuncture at Taichong (LR3) and Taixi (KI3) using resting-state functional magnetic resonance imaging. Fifteen healthy volunteers underwent resting-state functional magnetic resonance imaging of the brain 15 minutes before acupuncture, then received acupuncture at Taichong and Taixi using the nail-pressing needle insertion method, after which the needle was retained in place for 30 minutes. Fifteen minutes after withdrawal of the needle, the volunteers underwent a further session of resting-state functional magnetic resonance imaging, which revealed that the amplitude of low-frequency fluctuation, a measure of spontaneous neuronal activity, increased mainly in the cerebral occipital lobe and middle occipital gyrus (Brodmann area 18/19), inferior occipital gyrus (Brodmann area 18) and cuneus (Brodmann area 18), but decreased mainly in the gyrus rectus of the frontal lobe (Brodmann area 11), inferior frontal gyrus (Brodmann area 44) and the center of the posterior lobe of the cerebellum. The present findings indicate that acupuncture at Taichong and Taixi specifically promote blood flow and activation in the brain areas related to vision, emotion and cognition, and inhibit brain areas related to emotion, attention, phonological and semantic processing, and memory.

Chronic intermittent hypoxia and hypertension: a review of systemic inflammation and Chinese medicine.

Obstructive sleep apnea syndrome (OSAS) and hypertension commonly coexist. Clinical studies indicate that OSAS plays a key role in increasing the risk of prevalent hypertension. Chronic intermittent hypoxia (CIH) is the core pathological mechanism of OSAS, and has a close relationship with systemic inflammation. Growing evidence shows that CIH and hypertension are strongly related, involving markers or pathways indicative of systemic inflammation, such as high-sensitivity C-reactive protein (hs-CRP), interleukin-6, nuclear factor-kappa B, tumor necrosis factor-α, interleukin-8 and p38 mitogen-activated protein kinase (MAPK)-dependent pathways. Oxidative stress also plays an important role in this process, including in the activation of polymorphonuclear neutrophils. However, the pathophysiological and clinical significance of systemic inflammation in CIH and hypertension is not proven. This review article highlights the relationship between CIH and hypertension through systemic inflammation and the current interventions available in Chinese medicine, to offer a background for the future treatment of OSAS-related hypertension with integrative medicine.