Radiation dose in the thyroid and the thyroid cancer risk attributable to CT scans for pediatric patients in one general hospital of China.

OBJECTIVE: To quantify the radiation dose in the thyroid attributable to different CT scans and to estimate the thyroid cancer risk in pediatric patients. METHODS: The information about pediatric patients who underwent CT scans was abstracted from the radiology information system in one general hospital between 1 January 2012 and 31 December 2012. The radiation doses were calculated using the ImPACT Patient Dosimetry Calculator and the lifetime attributable risk (LAR) of thyroid cancer incidence was estimated based on the National Academies Biologic Effects of Ionizing Radiation VII model. RESULTS: The subjects comprised 922 children, 68% were males, and received 971 CT scans. The range of typical radiation dose to the thyroid was estimated to be 0.61-0.92 mGy for paranasal sinus CT scans, 1.10-2.45 mGy for head CT scans, and 2.63-5.76 mGy for chest CT scans. The LAR of thyroid cancer were as follows: for head CT, 1.1 per 100,000 for boys and 8.7 per 100,000 for girls; for paranasal sinus CT scans, 0.4 per 100,000 for boys and 2.7 per 100,000 for girls; for chest CT scans, 2.2 per 100,000 for boys and 14.2 per 100,000 for girls. The risk of thyroid cancer was substantially higher for girls than for the boys, and from chest CT scans was higher than that from head or paransal sinus CT scans. CONCLUSIONS: Chest CT scans caused higher thyroid dose and the LAR of thyroid cancer incidence, compared with paransal sinus or head CT scans. Therefore, physicians should pay more attention to protect the thyroid when children underwent CT scans, especially chest CT scans.

Evaluation of pluronic nanosuspensions loading a novel insoluble anticancer drug both in vitro and in vivo.

To improve the solubility, stability and the antitumor activity of a novel anticancer drug, 3-(4-bromopheny l)-2-(ethyl-sulfonyl)-6-methylquinoxaline1,4-dioxide (Q39), a poloxamer nanosuspension was developed by precipitation combined with high pressure homogenization in present study. In vitro characterizations of Q39 nanosuspension (Q39/NS), including particle size, polydispersity index (PI), morphology, crystalline, saturation solubility, stability and releases were evaluated. BABL/c nude mice bearing HepG2 cells were used as in vivo tumor models to evaluate the anti-tumor activity of Q39/NS after intravenous administration. The particle size and PI for Poloxamer188 nanosuspension (P188/NS) were (304±3) nm, and (0.123±0.005) respectively, and it was (307±5) nm and (0.120±0.007) for Poloxamer85 nanosuspension (P85/NS) correspondingly. The morphology of P188/NS was spherical shape while elliptoid shape for P85/NS. The crystalline of Q39/NS did not change as shown by the X-ray diffraction analysis. The stability of Q39/NS improved compared with the solution. The solubility of Q39 in P188/NS was 7.3 times higher than the original solubility, while it was 6 times for P85/NS. Sustained release as shown from the in vitro release test, together with the tumor-targeting as shown from in vivo NS distribution, may contribute to the enhanced in vivo antitumor activity of Q39/NS.

[Investigation on food contamination with parasites in Shanghai market].

OBJECTIVE: To understand the contamination status of food with parasites in Shanghai market, so as to provide the evidence for formulating the surveillance strategy in parasitic diseases and provide the technical support in the food safety. METHODS: The freshwater fish products, marine products, vegetables, snails and frogs were sampled with the cluster random method in the farmer-trades and supermarkets of the 18 districts in Shanghai City during 2005-2010 period, and all the specimen were screened by the digestion method, or crushing method or dissection method or saline floatation method to check the parasite metacercaria or larvae or eggs. RESULTS: A total of 5 185 specimen in 23 species of fishes were screened in fresh-water products, with parasite infection rate of 1.93%. About 4 033 specimens of 20 species of fishes and shrimps were screened and 1.76% of samples were infected with Clonorchis sinensis. Among all kind of fishes, the highest infection rate was 7.83% (48/613) in Pseudorasbora parve. No any infected specimen was found among 1 152 specimen of fresh water crustacean screened. Anisakis spp. were found in 12.7% of 433 specimens of 23 species of seawater products, among them, the higher infection rate of Anisakis spp. was found in Pneumatophorus japonicas and Trichiurus haumela with their infection rates of 50.00% (13/26) and 23.46% (42/179), respectively, which much higher than those found in other seawater products (P < 0.01). In 37 kinds of vegetables, the parasite eggs were found in one of 428 specimens with its infection rate of 0.47%, while no any parasite egg was found in 103 specimens of 10 kinds of fruits. No any Angiostrongylus cantonensis larvae were found in 330 snails, 31.37% of 102 frogs were found infected with Spirometra mansoni spargana. No any contamination with parasites was found in 116 meat specimens of pigs and cattle. In the same time, the intestinal parasite infection rate of residents was 0.42% (131/31 239). CONCLUSIONS: It is found that some of foods in Shanghai markets are contaminated with parasites. Therefore, it is necessary to enforce the activities in health education as well as to take integrated prevention measures in order to ensure the food safety.

Doxorubicin-loaded PEG-PCL copolymer micelles enhance cytotoxicity and intracellular accumulation of doxorubicin in adriamycin-resistant tumor cells.

BACKGROUND: Multidrug resistance remains a major obstacle to successful cancer chemotherapy. Some chemical multidrug resistance inhibitors, such as ciclosporin and verapamil, have been reported to reverse resistance in tumor cells. However, the accompanying side effects have limited their clinical application. In this study, we have developed a novel drug delivery system, ie, a polyethyleneglycol-polycaprolactone (PEG-PCL) copolymer micelle encapsulating doxorubicin, in order to circumvent drug resistance in adriamycin-resistant K562 tumor cells. METHODS: Doxorubicin-loaded diblock copolymer PEG-PCL micelles were developed, and the physicochemical properties of these micelles, and accumulation and cytotoxicity of doxorubicin in adriamycin-resistant K562 tumor cells were studied. RESULTS: Doxorubicin-loaded micelles were prepared using a solvent evaporation method with a diameter of 36 nm and a zeta potential of +13.8 mV. The entrapment efficiency of doxorubicin was 48.6% ± 2.3%. The micelles showed sustained release, increased uptake, and cellular cytotoxicity, as well as decreased efflux of doxorubicin in adriamycin-resistant K562 tumor cells. CONCLUSION: This study suggests that PEG-PCL micelles have the potential to reverse multidrug resistance in tumor cells.

Mesenchymal stem cells: a promising targeted-delivery vehicle in cancer gene therapy.

The targeting drug delivery systems (TDDS) have attracted extensive attention of researchers in recent years. More and more drug/gene targeted delivery carriers, such as liposome, magnetic nanoparticles, ligand-conjugated nanoparticles, microbubbles, etc., have been developed and under investigation for their application. However, the currently investigated drug/gene carriers have several disadvantages, which limit their future use in clinical practice. Therefore, design and development of novel drug/gene delivery vehicles has been a hot area of research. Recent studies have shown the ability of mesenchymal stem cells (MSCs) to migrate towards and engraft into the tumor sites, which make them a great hope for efficient targeted-delivery vehicles in cancer gene therapy. In this review article, we examine the promising of using mesenchymal stem cells as a targeted-delivery vehicle for cancer gene therapy, and summarize various challenges and concerns regarding these therapies.

[Prevention and control of intestinal nematode infection in Shanghai].

OBJECTIVE: To evaluate the current status of intestinal nematode infection in Shanghai and make recommendations for further control activities. METHODS: Retrospective review of the control program was made based on the change of nematode prevalence in Shanghai area since the 1950s, and challenges under the current situation were analysed. RESULTS: The intervention measures included chemotherapy, health education, sanitary disposal of human excreta and safe water supply. With the control strategy, socio-economical development and the change of farming patterns, the prevalence of intestinal nematode infection in population was reduced by 88.5%, from 62.6% in 1955 to 8.2% in 2000. Among them, ascaris infection decreased by 89.0%, from 52.1% to 6.3%, hookworm infection decreased by 99.0%, from 12.9% to 0.1%, but pinworm infection was still as high as 18.9% in 1999. CONCLUSION: Prevalence of nematode infection in Shanghai was considerably reduced. To match it with the current socio-economical development in the Municipality, however, more needs to be done. Sustainable control activities and surveillance are recommended.