Soil Properties,Nutrient Dynamics,and Soil Enzyme Activities Associated with Garlic Stalk Decomposition under Various Conditions

The garlic stalk is a byproduct of garlic production and normally abandoned or burned, both of which cause environmental pollution. It is therefore appropriate to determine the conditions of efficient decomposition, and equally appropriate to determine the impact of this decomposition on soil properties. In this study, the soil properties, enzyme activities and nutrient dynamics associated with the decomposition of garlic stalk at different temperatures, concentrations and durations were investigated. Stalk decomposition significantly increased the values of soil pH and electrical conductivity. In addition, total nitrogen and organic carbon concentration were significantly increased by decomposing stalks at 40°C, with a 5∶100 ratio and for 10 or 60 days. The highest activities of sucrase, urease and alkaline phosphatase in soil were detected when stalk decomposition was performed at the lowest temperature (10°C), highest concentration (5∶100), and shortest duration (10 or 20 days). The evidence presented here suggests that garlic stalk decomposition improves the quality of soil by altering the value of soil pH and electrical conductivity and by changing nutrient dynamics and soil enzyme activity, compared to the soil decomposition without garlic stalks.     

Diabetes Promotes DMH-Induced Colorectal Cancer by Increasing the Activity of Glycolytic Enzymes in Rats

The objective of the present study was to investigate the association between diabetes mellitus and colorectal carcinogenesis as well as the possible mechanism involved in this interaction. Diabetes rat models were induced with a low dose of STZ followed by a low dose of DMH to induce colorectal cancer. The formation of ACF in the colon and the incidence, number and size of tumors were measured. The activity of glycolytic enzymes in colonic tissues was also measured. The results demonstrated that both the total number of ACF and the number of foci that contain a different number of crypts were increased in diabetic rats. At the end of the experimental treatment, the incidence, number and size of tumors were also increased in diabetic rats. Overall, these data indicated that diabetes increased the risk of colorectal cancer. The activity of HK and PK in colonic tissues was increased in diabetic rats, whereas the activity of PDH was decreased. In addition, the activities of these enzymes in intratumor were higher than that of in peritumor. These data indicated that the high rate of glycolysis may play a role in colorectal carcinogenesis in diabetic rats.     

Regulation of the Escherichia coli cad operon: location of a site required for acid induction.

The cad operon encodes lysine decarboxylase and a protein homologous to amino acid antiporters. These two genes are induced under conditions of low pH, anaerobiosis, and excess lysine. The upstream regulatory region of the cad operon has been cloned into lacZ expression vectors for analysis of the sequences involved in these responses. Deletion analysis of the upstream region and cloning of various fragments to make cadA::lacZ or cadB::lacZ protein fusions or operon fusions showed that cadA was translated more efficiently than cadB and localized the pH-responsive site to a region near an upstream EcoRV site. Construction of defined end points by polymerase chain reaction further localized the left end of the regulatory site. The presence of short fragments bearing the regulatory region on high-copy-number plasmids greatly reduced expression from the chromosomal cad operon, suggesting that titration of an essential activator protein was occurring. With nonoptimal polymerase chain reaction conditions, a set of single point mutants were made in the upstream regulatory region. Certain of these altered regulatory regions were unable to compete for the regulatory factor in vivo. The locations of these essential bases indicate that a sequence near the EcoRV site is very important for the activator-DNA interaction. In vivo methylation experiments were conducted with cells grown at pH 5.5 or at pH 8, and a difference in protection was observed at specific G residues in and around the region defined as important in pH regulation by the mutation studies. This work defines essential sequences for acid induction of this system involved in neutralization of extracellular acid.     

Toll-like receptor 4 contributes to uterine activation by upregulating pro-inflammatory cytokine and CAP expression via the NF-κB/P38MAPK signaling pathway during pregnancy

Evidence indicates that inflammatory response is significant during the physiological process of human parturition; however, the specific signaling pathway that triggers inflammation is undefined. Toll-like receptors (TLRs) are key upstream gatekeepers that control inflammatory activation before preterm delivery. Our previous study showed that TLR4 expression was significantly increased in human pregnancy tissue during preterm and term labor. Therefore, we explore whether TLR4 plays a role in term labor by initiating inflammatory responses, therefore promoting uterine activation. The results showed that expression of TLR4, interleukin-1β (IL-1β), IL-6, tumor necrosis factor-α (TNF-α), CC chemokine ligand 2 (CCL-2), and uterine contraction-associated proteins (CAPs) was upregulated in the human and mice term labor (TL) group compared with the not-in-labor (TNL) group, and the TLR4 level positively correlated with CAP expression. In pregnant TLR4-knockout (TLR4^−/−) mice, gestation length was extended by 8 hr compared with the wild-type group, and the expression of IL-1β, IL-6, TNF-α, CCL-2, and CAPs was decreased in TLR4^−/− mice. Furthermore, nuclear factor-κB (NF-κB) and P38MAPK activation is involved in the initiation of labor but was inhibited in TLR4^−/− mice. In uterine smooth muscle cells, the expression of inflammatory cytokines and CAPs decreased when the NF-κB and P38MAPK pathway was inhibited. Our data suggest that TLR4 is a key factor in regulating the inflammatory response that drives uterine activation and delivery initiation via activating the NF-κB/P38MAPK pathway.     

Real-time monitoring of nucleic acid ligation in homogenous solutions using molecular beacons

Nucleic acids ligation is a vital process in the repair, replication and recombination of nucleic acids. Traditionally, it is assayed by denatured gel electrophoresis and autoradiography, which are not sensitive, and are complex and discontinuous. Here we report a new approach for ligation monitoring using molecular beacon DNA probes. The molecular beacon, designed in such a way that its sequence is complementary with the product of the ligation process, is used to monitor the nucleic acid ligation in a homogeneous solution and in real-time. Our method is fast and simple. We are able to study nucleic acids ligation kinetics conveniently and to determine the activity of DNA ligase accurately. We have studied different factors that influence DNA ligation catalyzed by T4 DNA ligase. The major advantages of our method are its ultrasensitivity, excellent specificity, convenience and real-time monitoring in homogeneous solution. This method will be widely useful for studying nucleic acids ligation process and other nucleic acid interactions.     

Novel antimicrobial peptides isolated from the skin secretions of Hainan odorous frog, Odorrana hainanensis

Intraperitoneal (i.p.) administration of the synthetic agonist of the glucagon like peptide-1 (GLP-1) receptor exenatide reduces food intake. Here, we evaluated possible peripheral pathways for this reduction. Exenatide (0.5 μg/kg, i.p.) was given to three, overnight food-deprived, groups of rats: total subdiaphragmatic vagotomy (VGX, severs the vagus nerve), celiaco-mesenteric ganglionectomy (CMGX, severs the splanchnic nerve) and combined VGX/CMGX. Following the injection, meal sizes (MSs) and intermeal intervals (IMIs) were determined for a total of 120 min. We found that exenatide reduced the sizes of the first two meals but failed to prolong the IMI between them, that VGX attenuated the reduction of the first MS, and that VGX, CMGX and combined VGX/CMGX attenuated the reduction of the second MS by exenatide. Therefore, the vagus nerve appears necessary for the reduction of the first MS by exenatide, whereas both nerves appear necessary for the reduction of the second MS by this peptide.     

Structure-activity relationships of 4-hydroxy-4-biaryl-proline acylsulfonamide tripeptides: A series of potent NS3 protease inhibitors for the treatment of hepatitis C virus

The design and synthesis of a series of tripeptide acylsulfonamides as potent inhibitors of the HCV NS3/4A serine protease is described. These analogues house a C4 aryl, C4 hydroxy-proline at the S2 position of the tripeptide scaffold. Information relating to structure-activity relationships as well as the pharmacokinetic and cardiovascular profiles of these analogues is provided.