Enhanced production of ganoderic acids and cytotoxicity of Ganoderma lucidum using solid-medium culture.

Submerged cultures of Ganoderma lucidum are used to produce fungal mycelium, which is used as a functional food and in the production of various triterpenoids, including ganoderic acids (GAs). Specific culture approaches that produce fungal mycelium with high levels of GAs and good biological activity are critical in the functional food industry. In this study, a solid-medium culture approach to producing mycelium was compared to the submerged culture system. Production of GAs, biomass, intracellular polysaccharides, and cytotoxicity of the cultured mycelium were compared as between solid and submerged culture. Growing G. lucidum strains on solid potato dextrose agar medium increased biomass, the production of ganoderic acid 24 (lanosta-7,9(11), 24-trien-3α-o1-26-oic acid), GAs, and total intracellular polysaccharides as compared to fungi grown in submerged culture. Triterpenoid-enriched methanol extracts of mycelium from solid-medium culture showed higher cytotoxicity than those from submerged culture. The IC(50) values of methanol extracts from solid-medium culture were 11.5, 8.6, and 9.9 times less than submerged culture on human lung cancer cells CH27, melanoma cells M21, and oral cancer cells HSC-3 respectively. The squalene synthase and lanosterol synthase coding genes had higher expression on the culture of solid potato dextrose medium. This is the first report that solid-medium culture is able to increase GA production significantly as compared to submerged culture and, in the process, produces much higher biological activity. This indicates that it may be possible to enhance the production of GAs by implementing mycelium culture on solid medium.

[Nursing care for children undergoing percutaneous endoscopic gastrostomy].

Ever since percutaneous endoscopic gastronomy (PEG) was used for the first time in 1980 by Gauderer, Ponsky, Izant et al., It has been widely used in patients incapable of oral feeding. It is a safe and effective technique for long-term nutritional support in children, and easy to perform, as only local anesthesia or heavy sedation is required PEG can prevent children from suffering from nasopharyngeal and esophageal erosions due to repeated insertion of nasogastric tubes and the complication of aspiration pneumonia. It is therefore an alternative for children who need long-term feeding. In this article we review the literature on PEG and give a full description of its indications, complications, as well as advice on when to change gastrostomy tubes, and on nursing care, in the hope that this will be useful reference material for medical staff.