[Effects of microbial agent inoculation on bacterial community diversity in the process of pig manure composting].

PCR-DGGE method was adopted to study the effects of inoculating exogenous microbial agent on the bacterial community diversity in the process of fresh pig manure high-temperature aerobic composting. Exogenous microbial agent inoculation promoted the composting process, with the high-temperature period being advanced by 2 days than that of non-inoculation. DGGE pattern analysis showed that during composting, the dominant bacteria changed significantly, with the Shannon-Wiener index of bacterial community at different composting periods varied obviously. The sequencing of DGGE-distinguished bands showed that Clostridium stercorarium subsp. thermolacticum sp. was the dominant group in the whole composting process. Uncultured bacteria Bacillus coagulans sp. and Clostridium thermocellum sp. became the main groups on the 10th and 16th day after microbial agent inoculation, while uncultured Firmicutes sp. and delta proteobacterium became the dominant groups on the 5th and 16th days in the treatment non-inoculation, respectively. Un-dominant group Ureibacillus thermosphaericu sp. and uncultured Silvimonas sp. appeared in the late period of well rotted composting, while uncultured soil bacteria mainly appeared in the initial and high-temperature periods. UPGMC cluster analysis showed that exogenous microbial agent inoculation obviously affected the bacterial community structure in different composting periods, and the main component analysis of DGGE patterns in composting process showed that the bacterial community was mainly affected by the exogenous microbial agent inoculation.

[Effects of slow/controlled release fertilizers on the growth and nutrient use efficiency of pepper].

Pot trails were conducted from 2003 to 2005 to study the effects of slow/controlled release fertilizers on the growth and nutrient use efficiency of pepper. The results indicated that in comparison with conventional splitting fertilization (T1), basal application of polymer-coated controlled release fertilizer (T2) enhanced the single fruit mass and vitamin C concentration, improved the root activity, and increased the fruit yield by 8.4%, but no significant effect was observed on the dissoluble sugar concentration in fruit. NH4MgPO4-coated controlled release fertilizer (T3) increased the dissoluble sugar concentration by 5.67%, but had less effect on single fruit mass and vitamin C concentration. Under the application of T3, the root system had a vigorous growth at early stages but became infirm at later stages, resulting in a lower yield. Comparing with T1, the application of 3 slow release fertilizers increased the dissoluble sugar concentration in fruit, enhanced the root activity, but had less effect on the yield. All test slow/controlled release fertilizers increased the use efficiency of N, P, and K significantly, with an exception for T2 which increased the use efficiency of N and K but decreased that of P. It was demonstrated that an appropriate application of slow/controlled release fertilizers could enhance pepper' s root activity and improve nutrient use efficiency.

[CGRP may take part in the effect of electroacupuncture in resisting acute myocardial ischemic injury].

OBJECTIVE: To probe into the relationship between "Xinshu" (BL 15)-"Jueyinshu" (BL 14) of the Bladder Channel and the heart and the underlying mechanism of electroacupuncture (EA) in resisting acute myocardial ischemia (AMI) in rats. METHODS: A total of 24 male Wistar rats were randomly divided into control, model and EA groups with 8 cases in each group. AMI model was duplicated by intraperitoneal injection of 2% isoproterenol (ISO, 100 mg/kg). EA (pulse duration 300 micros, frequency 2-20 Hz, output voltage 3. 5-5 V) was applied to BL14 and BL15 on the left side for 30 min, twice in a day (with an interval of 12 h). After decapitation, blood samples, myocardial tissue and spinal cord (T1-T6) were collected respectively for detecting serum creatine kinase (CK, with chromatometry) and calcitonin gene-related peptide (CGRP) contents in the plasma, myocardium and the spinal cord (with radioimmunoassay). RESULTS: In comparison with control group, serum CK of both model group and EA group increased significantly (P < 0. 01), and plasma CGRP content of model group lowered lightly; while compared with model group, CK content of EA group decreased obviously (P < 0.05) and plasma CGRP of EA group increased evidently (P < 0.05). No significant differences were found among 3 groups in myocardial CGRP contents and between control group and model group in spinal CGRP contents (P > 0.05). CONCLUSION: EA of "Xinshu" (BL 15)-"Jueyinshu" (BL 14) may suppress isoproterenol-injection induced myocardial injury and plasma CGRP possibly takes part in the protective effect of EA in resisting myocardial ischemia injury.

[Research on the differentially expressed genes related to the relatively specific connection between the heart meridian and the heart].

OBJECTIVE: To study the scientific basis of specific correlation between the meridian and the Zang- or Fu organ by using gene differential expression (gene-chip technique) in the rat. METHODS: Twenty-one SD rats were randomly and evenly divided into control group, sham-myocardial ischemia (MI) group, MI group, electroacupuncture (EA)-Heart-Meridian (HT) group, EA-Lung-Meridian (LU) group and EA-Small-Intestine-Meridian (SI) group. EA (frequency 2 Hz, stimulating strength 5 V, pulse duration 300 mus) was applied to "Shenmen" (HT 7)- "Tongli" (HT 5) (Heart Meridian), "Y anglao" (SI 6)- "Zhizheng" (SI 7) (Small Intestine Meridian), "Taiyuan" (LU 9)-"Lieque" (LU 7) (Lung Meridian) for 20 min, once daily and continuously for 3 days. Myocardial ischemia model was duplicated by occlusion of the anterior descending branch of the left coronary artery, and myocardial tissue of the left ventricle was taken 3 days after EA treatment for analyzing the differentially expressed genes in different groups with rat whole gene U 230 sequence chips (offered by Affymetrix Company). RESULTS: Compared with model group, among the differentially expressed genes being twofolds and above, the up-regulated and the down-regulated were 20 and 70 in EA-HT group, 18 and 26 in EA-SI group, and 14 and 20 in EA-LU group separately. Few same genes with the same differential expression were found among the 3 EA groups. CONCLUSION: There is exactly a molecular basis in the correlation between Heart Meridian and the heart, and EA of Heart Meridian, Small Intestine Meridian and Lung Meridian have their own special signaling pathways.

[Plasticity of bone marrow mesenchymal stem cells differentiating into cardiomyocytes and the potential of cardiac therapeutics].

Current treatments for ischemic cardiomyopathy aim at minimizing the deteriorated consequences of damaged myocardium. Recent stem cell researches have provided major impetus for the possibility of treating heart failure by generating new myocardium and vascular structures. Bone marrow mesenchymal stem cells (MSCs) , also referred to as marrow stromal cells, differentiate readily into chondrocytes, adipocytes, and osteocytes. Recent provocative data suggest that they can also express phenotypic characteristics of endothelial, neural, smooth muscle, skeletal myoblasts, and cardiac myocytes. The multilineage potential, no immune reaction if self-transplantation, and the relative easiness of expansion in culture make MSCs a promising source of cells for medical therapies. Recent researches demonstrate that implantation of intramyocardial MSCs can prevent deteriorated remodeling and improve cardiac function, although the underlying mechanisms need to be further clarified. This review summarized recent studies in the recognition of MSCs, particularly the MSC plasticity into cardiomyocytes, factors and signal pathways that mediate MSC differentiation, and animal studies as well as clinic trials of the implantation of MSCs in postinfarct myocardium.

Passage-restricted differentiation potential of mesenchymal stem cells into cardiomyocyte-like cells.

Mesenchymal stem cells (MSCs) have limited ability to differentiate into cardiomyocytes and the factors affect this process are not fully understood. In this study, we investigated the passage (P)-related transdifferentiation potential of MSCs into cardiomyocyte-like cells and its relationship to the proliferation ability. After 5-azacytidine treatment, only P4 but not P1 and P8 rat bone marrow MSCs (rMSCs) showed formation of myotube and expressed cardiomyocyte-associated markers. The growth property analysis showed P4 rMSCs had a growth-arrest appearance, while P1 and P8 rMSCs displayed an exponential growth pattern. When the rapid proliferation of P1 and P8 rMSCs was inhibited by 5-bromo-2-deoxyuridine, a mitosis inhibitor, only P1, not P8 rMSCs, differentiated into cardiomyocyte-like cells after 5-azacytidine treatment. These results demonstrate that the differentiation ability of rMSCs into cardiomyocytes is in proliferation ability-dependent and passage-restricted patterns. These findings reveal a novel regulation on the transdifferentiation of MSCs and provide useful information for exploiting the clinical therapeutic potential of MSCs.