BACKGROUND:Lymph-targeted tracing and therapy based on carbon nanotubes have been one of the hottest researches on targeting tumor diagnosis and treatment. To evaluate the accumulation of carbon nanotubes in axil ary lymph node can provide experimental evidences for developing nano-tracers and drug carriers which are more lymph-specific and more biocompatible. OBJECTIVE:To study the accumulation of the intravenously injected carboxylated single-wal ed carbon nanotubes in axil ary lymph nodes of Sprague-Dawley rats, and to evaluate their effect on blood cel s. METHODS:Sixty-four Sprague-Dawley rats were randomly divided into two groups. Rats in testing group were injected with carboxylated single-wal ed carbon nanotubes suspension (2 mg/kg), while those in control group were injected with 5%glucose solution (1 mL/kg), both through the tail vein, three times per week. Four periods of 7, 60, 90 and 120 days were set (the 120-day period referred to 90 days of administration fol owed by 30 days of drug withdrawal). At the end of each period, eight rats from each group were randomly picked out, to col ect blood samples via the abdominal aorta for blood routine test. Final y the axil ary lymph nodes were observed, and the lymph node samples of rats in the testing group were col ected and analyzed at 120 days by transmission electron microscope. RESULTS AND CONCLUSION:Compared with the control group, black staining of axil ary lymph nodes of rats in testing group was not obvious at the end of the 7-day period. However, with the increase of the dosing periods, the lymph nodes of the rats in the testing group became enlarged, firm and black stained, coupled with a significant rising in the percentage of blood neutrophils. After 30 days of drug withdrawal, the size of the rat axil ary lymph nodes was reduced and black staining partly faded, with the decreasing of blood neutrophil percentage. Under the transmission electron microscope, abundant carboxylated single-wal ed carbon nanotubes were uptaken by lymphocytes to form a large number of phagocytic vacuoles after drug withdrawal for 30 days. It indicates that the short-term tracing of rat axil ary lymph nodes by carboxylated single-wal ed carbon nanotubes injected through the tail vein is relatively weak, while the long-term intravenous injection can cause their accumulation in rat axil ary lymph nodes, coupled with the increase of neutrophils;after drug withdrawal, the carboxylated single-wal ed carbon nanotubes can be slowly cleared by the lymph nodes.

Based on the analysis of definition and the causes of excessive medical treatment, this paper discus-ses the harm of excessive medical treatment concretely, including increased health care costs, the waste of medical resources, worsening doctor-patient conflicts that influence the development of holistic medicine. And in the per-spective of ethics, professional spirit and the humanistic quality, it puts forward the prevention and countermeasures to solve the problem of excessive medical treatment.

To reveal the relationship between endophytic fungi and the functional components, saccharides and flavonoids in the mycelia or fermented liquor of 21 endophytic fungi in D.officinale were detected using HPLC and UV spectrophotometer.The results showed that the ethyl acetate extracts from 21 fungal strains all contain flavonoids.According to the chromatographic retention time of HPLC and UV spectra characteristics of flavonoids, strain DO49 was found produce naringenin, strains DO23, DO81 and DO83 were found produce rutin.The water-soluble extracts from 21 strains all had polysaccharides.However, there was difference in the composition of monosaccharides derived from polysaccharides among different strains.According to the composition of monosaccharides and the peak area ratio of mannose and glucose, the fungal strains including DO23, DO26, DO81, DO54, DO55, DO83 product polysaccharides associated with D.officinale were selected.In conclusion, based on the saccharides and flavonoids, the excellent endophytic fungal strains DO23, DO81 and DO83 were selected, which could produce the same flavonoids and similar polysaccharides in D.officinale.