Peroxidase activities of gold nanowires synthesized by TMV as template and their application in detection of cancer cells.

A sensing methodology that combines Au, tobacco mosaic virus (TMV), and folic acid for selective, sensitive, and colorimetric detection of tumor cells based on the peroxidase-like activity was reported in this study. Gold nanowires with a high aspect ratio were synthesized using TMV as a template. Au@TMV nanowire (AT) complex was obtained with diameter of 4 nm and length between 200 and 300 nm. In addition, since TMV was biocompatible and had many amino and carboxyl groups on its surface, AT was conjugated by folate to form a folic acid (FA)-conjugated AT composite (ATF) and tested by FTIR measurements. Furthermore, the peroxidase-like properties were studied and the optimal conditions for mimic enzyme activity were optimized. Finally, HeLa and other tumor cells expressed excessive receptors of folate on the surface, which can specifically bind to folic acid. As the specific binding of ATF with HeLa cells, the peroxidase properties of ATF were used for detection of cancer cells (Scheme 1). The cancer cells were detected not only qualitatively but also quantitatively. In this study, as low as 2000 cancer cells/mL could be detected using the current method.

Transmission of hepatitis E virus from rabbits to cynomolgus macaques.

The recent discovery of hepatitis E virus (HEV) strains in rabbits in the People's Republic of China and the United States revealed that rabbits are another noteworthy reservoir of HEV. However, whether HEV from rabbits can infect humans is unclear. To study the zoonotic potential for and pathogenesis of rabbit HEV, we infected 2 cynomolgus macaques and 2 rabbits with an HEV strain from rabbits in China. Typical hepatitis developed in both monkeys; they exhibited elevated liver enzymes, viremia, virus shedding in fecal specimens, and seroconversion. Comparison of the complete genome sequence of HEV passed in the macaques with that of the inoculum showed 99.8% nucleotide identity. Rabbit HEV RNA (positive- and negative-stranded) was detectable in various tissues from the experimentally infected rabbits, indicating that extrahepatic replication may be common. Thus, HEV is transmissible from rabbits to cynomolgus macaques, which suggests that rabbits may be a new source of human HEV infection.

Elements of chronic disease management service system: an empirical study from large hospitals in China.

At present, more patients suffer from multiple chronic diseases. However, the hospital's existing chronic disease management is carried out according to the department. This means that a patient needs to go to more than one department for a chronic disease treatment. Therefore, this study proposes 6 dimensions (organizational management, medical service support, medical service, community alliance, self-management support, management information system) and 36 questions, to help evaluate the current chronic disease management system in China's large third-class hospitals. In this study, 143 survey samples from doctors and nurses were collected. A principal component analysis was used to extract three key elements of chronic disease management service delivery system (service management organization, management information system, medical core service). Then, multiple regression was used to establish the relationship model between the overall performance of the system and the main elements. Three key service nodes of the system (medical specialist support, patient tracking management and personalized intervention) were determined according to the weight of the regression model. The regression coefficients of the above three main elements show a similar impact on the overall performance of the system, but the key service nodes under each major element have relative differences, including medical specialist support, patient tracking management and personalized intervention. Finally, to establish a chronic disease management system with multiple departmental continuous care for chronic diseases, it is necessary to improve the chronic disease management system from three aspects of medical specialty support, patient tracking management and personalized intervention. This paper proposes corresponding improvement strategies.

Logistic modeling to predict the minimum inhibitory concentration (MIC) of olive leaf extract (OLE) against Listeria monocytogenes.

Olive leaf extract (OLE) has been increasingly recognized as a natural and effective antimicrobial against a host of foodborne pathogens. This study attempts to predict the minimum inhibitory concentration (MIC) of OLE against Listeria monocytogenes F2365 by utilizing the asymptotic deceleration point (PDA) in a logistic model (LM), namely MIC-PDA. The experimental data obtained from the inhibitory rate (IR) versus OLE concentration against L. monocytogenes were sufficiently fitted (R2 = 0.88957). Five significant critical points were derived by taking the multi-order derivatives of the LM function: the inflection point (PI), the maximum acceleration point (PAM), the maximum deceleration point (PDM), the absolute acceleration point (PAA), and the asymptotic deceleration point (PDA). The PDA ([OLE] = 37.055 mg/mL) was employed to approximate the MIC-PDA. This MIC value was decreased by over 42% compared to the experimental MIC of 64.0 mg/mL, obtained using the conventional 2-fold dilution method (i.e., MIC-2fold). The accuracy of MIC-PDA was evaluated by an in vitro L. monocytogenes growth inhibition assay. Finally, the logistic modeling method was independently validated using our previously published inhibition data of OLE against the growths of Escherichia coli O157:H7 and Salmonella enteritidis. The MIC-PDA (for [OLE]) values were estimated to be 41.083 and 35.313 mg/mL, respectively, compared to the experimental value of 62.5 mg/mL. Taken together, MIC-PDA, as estimated from the logistic modeling, holds the potential to shorten the time and reduce cost when OLE is used as an antimicrobial in the food industry.

Natural flagella-templated Au nanowires as a novel adjuvant against Listeria monocytogenes.

A simple method was developed for the extraction and purification of bacterial flagella with a yield of a concentration of 113.22 ± 5.64 mg mL-1. Gold (Au) nanowires were synthesized using the bacterial flagella as the template. Transmission Electron Microscopy (TEM) analysis showed that the nanowires were scarcely clustered as stiff (no tendency to bend or fold) and straight nanorods with homogeneous surface and a uniform aspect ratio over 60. Fourier Transform Infrared (FT-IR) spectroscopic studies revealed the deep involvement of the functional groups located within and on the surface of flagellin, including C-N, N-H, O-H, and C[double bond, length as m-dash]O. The profound transformation observed in the absorption profiles of these groups supported the notion that both chemical (reduction) reaction and physical (electrostatic) binding of Au occurred during the formation of Au nanowires. Verbascoside, oleuropein, and olive leaf extract (OLE) have been shown to inhibit the growth of Listeria monocytogenes completely at their respective Minimal Inhibitory Concentrations (MICs) of 20, 64, and 64 mg mL-1. In contrast, the synthesized Au nanowires demonstrated high electrocatalytic activity and reduced the MICs of the three antibacterial compounds by half. Moreover, results from the AMES assays indicated that the synthesized Au nanowires had no mutagenic activities at the catalytic concentration used, 128 µg mL-1. Therefore, the Au nanowires fabricated in this work have the potential to be used as new antimicrobial food packaging materials to enhance food safety.