DNA-Based Fluorescent Nanoprobe for Cancer Cell Membrane Imaging.

As an important barrier between the cytoplasm and the microenvironment of the cell, the cell membrane is essential for the maintenance of normal cellular physiological activities. An abnormal cell membrane is a crucial symbol of body dysfunction and the occurrence of variant diseases; therefore, the visualization and monitoring of biomolecules associated with cell membranes and disease markers are of utmost importance in revealing the biological functions of cell membranes. Due to their biocompatibility, programmability, and modifiability, DNA nanomaterials have become increasingly popular in cell fluorescence imaging in recent years. In addition, DNA nanomaterials can be combined with the cell membrane in a specific manner to enable the real-time imaging of signal molecules on the cell membrane, allowing for the real-time monitoring of disease occurrence and progression. This article examines the recent application of DNA nanomaterials for fluorescence imaging on cell membranes. First, we present the conditions for imaging DNA nanomaterials in the cell membrane microenvironment, such as the ATP, pH, etc. Second, we summarize the imaging applications of cell membrane receptors and other molecules. Finally, some difficulties and challenges associated with DNA nanomaterials in the imaging of cell membranes are presented.

Antidiarrheal effect of ethanol extract from Lophatheri Herba and its effect on isolated jejunal smooth muscle in rabbits.

Lophatheri Herba is a traditional Chinese medicine, which is commonly used in the treatment of fever, stomatitis, urodynia. The aim of the study is to evaluate the antidiarrheal activity of the ethanol extract of Lophatheri Herba (Gramineae, ELH) and observe its effect on isolated jejunum smooth muscle in rabbits, so that we can provide a possible pharmacological basis for its clinical use. Methods: In vivo, the antidiarrheal activity of ELH (250, 500 and 1000 mg/kg; orally) in castor oil-induced Kun Ming mice was evaluated. In vitro, the effect of ELH (0.01-10 mg/mL) on the spontaneous and ACh (10µM)/K+ (60mM)-induced contraction of isolated rabbit jejunum smooth muscle was studied. The possible mechanism of spasmolytic effect of ELH (1, 3mg/mL) was explored by pretreatment of intestinal tract with CaCl2. Results: ELH (500 and 1000mg/kg) exhibited antidiarrheal effect and it (0.01-10 mg/mL) inhibited the spontaneous and ACh/K+-induced contraction with an EC50 value of 1.27 (0.89-1.34), 0.76 (0.54-1.02) and 0.34 (0.27-0.53), it also shifted the concentration-response curves of CaCl2 to right with decreased in max, similar to verapamil. ELH has significant antidiarrheal and spasmolytic effect, this provides the pharmacological basis for use in gastrointestinal disorders.

Cropland degradation and nutrient overload on Hainan Island: A review and synthesis.

As the only "tropical base of agricultural production" in China, Hainan lsland is vigorously developing high-value agriculture and is becoming the province with the highest proportion of cash crops. However, this intensive farming with large nutrient inputs has caused cropland degradation, nitrogen (N) and phosphorus (P) overloads and water pollution, which have been reversed to initiate the construction of free trade ports. Here, we systematically review the status, driving factors, and environmental impacts of cropland degradation and nutrient overload with quantified evaluations and compared with other global tropics. Over the last 30 years, the soil pH in Hainan decreased by 0.3 units, and the soil organic carbon (SOC) decreased by 20%. This soil degradation has consequently aggravated nutrient losses, caused low use efficiency, and has required farmers add additional large nutrient to maintain harvests. P overuse is more serious than N overuse in Hainan due to the misuse of high P content compound fertilizers. The current N and P usage densities were 4% and 66% higher than the national average per crop season, i.e., 301 kg N ha-1 and 98 kg P ha-1, respectively, and the application rates were even higher for vegetables, i.e., 43% and 115% higher than the national average for vegetables. Consequently, water quality degradation occurred. The nutrient contents of several estuaries have exceeded the Class III standards. Potential improvement strategies are proposed: (i) Organic materials must be recycled to curb the declines in SOC and pH, and more benefits would be obtained by together use of biochar. (ii) Nutrient quotas must be implemented to balance nutrient budgets and reduce excessive surpluses and losses. (iii) The service functions of ecological protection zones for water and soil conservation must be strengthened. These strategies also apply to other global tropics that face similar challenges of soil and ecological degradation.

[Expression of Fas protein in myocardiac tissue of viral myocarditis and dilated cardiomyopathy].

OBJECTIVE: To study the pathogenesis of viral myocarditis (VMC) and dilated cardiomyopathy (DCM) and their relationship. METHODS: Sixty samples including 20 VMC, 20 DCM and 20 controls were collected. The expression of Fas protein in myocardium of each group was detected by modified immunohistochemistry with unequivocal brown staining in the myocardial membrane scored as positive, and the results of positive reaction were analyzed by Ridit test. RESULTS: Fas protein expression increased obviously in VMC and DCM groups as compared with that of the control group. The difference of positive results between each group analyzed by Ridit test was statistically significant (P<0.005). Statistically significant differences were found between VMC and control groups as well as between DCM and control groups (P<0.05), but not between VMC and DCM groups (P>0.05) by multiple comparison Ridit test. CONCLUSION: The expression of Fas protein is significantly higher in the VMC and DCM groups than in that of the control group. These results suggest that both the VMC and DCM may share a similar pathogenesis, which most likely involves cell apoptosis.