Viral and Bacterial Etiology of Acute Diarrhea among Children under 5 Years of Age in Wuhan, China / 中华医学杂志(英文版)

<p><b>BACKGROUND</b>Acute diarrhea remains the serious problem in developing countries, especially among children under 5 years of age. Currently, only two or three common diarrhea pathogens were screened at most hospitals in China. The aim of this study was to provide a wide variety of diarrhea pathogens and their antimicrobial resistance patterns in children under 5 years of age.</p><p><b>METHODS</b>Totally 381 stool samples collected from Tongji Hospital between July 1, 2014 and June 30, 2015 were tested by culture and/or polymerase chain reaction for eight kinds of bacteria and five kinds of viruses. An antimicrobial sensitivity test was performed using dilution method recommended by the Clinical and Laboratory Standards Institute.</p><p><b>RESULTS</b>Viral infections were mainly identified in infants (0-11 months), whereas bacterial infections were more prevalent in the age of 24-59 months. About 69.8% of samples were positive for at least one pathogen, 51.7% of samples were virus positive, followed by bacteria positive cases (19.4%), and 12.6% of cases displayed co-infections with two viruses or a virus and a bacterium. Rotavirus was the most prevalent pathogen, followed closely by norovirus, while Salmonella was the most commonly isolated bacteria, followed by diarrheagenic Escherichia coli (DEC) and Campylobacter. More than 40% of Salmonella spp. and DEC isolates were resistant to first-line antibiotics (ampicillin, trimethoprim-sulfamethoxazole, and tetracycline). Around 10% of Salmonella spp. isolates were resistant to ceftriaxone and ciprofloxacin simultaneously. Campylobacter spp. displayed high resistance to ciprofloxacin but kept low resistance to azithromycin and doxycycline.</p><p><b>CONCLUSIONS</b>The etiology of acute diarrhea varies in children of different age groups. The high frequency of infection with viruses suggests the urgent demand for new viral vaccine development. Proper use of antibiotics in the treatment of acute diarrhea is crucial due to the high level of antibiotic resistance.</p>

Effect of the in vitro culture and cryopreservation on the growth of the microencapsulated recombinant cell and endostatin production / 生物工程学报

Microencapsulated recombinant cells technology is a novel approach to tumors therapy. It is necessary to prepare a plenty of the microcapsules with better cell viability and higher endostatin production in order to bring this technology into the clinic. The in vitro culture and cryopreservation are very important parameters in the preparation of microencapsulated cells. In this work, we studied the effect of the in vitro culture and cryopreservation on microencapsulated recombinant cells growth and endostatin production and the effect of the in vitro culture on the cryopreservation of microencapsulated recombinant cells. The results showed that the time of in vitro culture potently affected microencapsulated recombinant CHO cells growth in vivo, endostatin production and the microcapsule stability. The microcapsule kept intact after 36 days of implantation when the in vitro culture time was under 4 days. The thawed microencapsulated recombinant CHO cells had better cell growth and higher endostatin production after 40 days of cryopreservation when the in vitro culture time was 4 days and 8 days. Therefore, the best in vitro culture time was 4 days according to the results of the in vivo culture and cryopreservation and the cryopreservation did not affect microencapsulated recombinant CHO cells growth in vivo, endostatin production and the microcapsule stability.

Preparation and cultivation of microencapsulated recombinant CHO cells / 生物工程学报

Transplantation of the microencapsulated recombinant cells is a novel alternative approach to gene therapy of tumors. The semi-permeable membrane of microcapsule protects cells from host's immune rejection, increases the efficiency of gene transfer and reduces the need for frequent injection. Optimization of the preparation and culture is needed to acquire biological microcapsule with high cell viability and protein production. In this work, we studied the effect of different preparation and culture condition on the microencapsulated recombinant CHO cells growth and endostatin production. The result showed that the inoculum cells growth phase and seeding density potently affected the growth and endostatin production of the recombinant CHO cells in the microcapsule. The exponential growth phase recombinant CHO cells with a seeding density of 1 x 10(6) - 2 x 10(6) cells/ mL microcapsules benefited to the cells growth and endostatin production. The time of preparation was another important effect factor of cells viability, the cells viability decreased with the increase of preparation time and the time of preparation should be under 5h for maintaining the cell viability and endostain production. The highest viable cell density and endostatin production was acquired when the microcapsule percentage was 5% in the culture of the microencapsulated cells, the cell growth and endostatin production decreased with the increase of the microcapsule percentage.

Experimental study of microencapsulated nerve cell/tissue for transplantation / 中国康复理论与实践

@#ObjectiveTo investigate the feasibility of poly l lysne to preparation microencapsules for cell transplantation therapies.MethodsUsing drop generative technique preparation Alginate poly l lysne Alginate (APA) microencapsules containing nerve cell/tissue. The concentration of nerve growth factor in supernatant was detected by two antibody sandwich method of enzyme linked immunosorbent assay.ResultsThe nerve cell/tissue in microencapsules retain reliable cell viability and function. Conclusions The APA is proved with reliable biocompatibility and strength,would work as an immunoisolation tools to exert important function in nerve renovate.

Study of alginate/chitosan microcapsules for immobilization of Escherichia coli DH5 alpha / 生物工程学报

Objective proteins synthesized from genetically recombined Escherichia coli strain (E. coli) have been successfully produced by microbe fermentation, but complicated separation and purification steps always make against the maintenance of activities as well as increase the cost. Aiming at simplifying the process, an idea of administrating directly the microencapsulated genetically recombined E. coli is proposed. In this paper, study on culture of E. coli DH5 alpha immobilized in alginate/chitosan (ACA) microcapsule is presented. It was found that E. coli DH5 alpha grew well in the microcapsule with stable growth period longer than that of suspension culture, and cell aggregation phenomenon was observed. In vivo experiments showed that ACA microcapsules with E. coli DH5 alpha stayed over 48 h in mouse intestine, and the morphology of microcapsules was kept intact. These preliminary results have demonstrated that administration of microencapsulated E. coli DH5 alpha is safe, which laied the foundation for microencapsulated genetically recombined E. coli as carriers of gene engineering drugs.