Polyethylene glycol (PEG) is extensively used to increasing the in vivo and in vitro stability of liposomes. However, PEGylated liposomes also produce some negative effects with further research, such as low cellular uptake, poor "endosomal escape" of pH sensitive liposome (PSL) and accelerated blood clearance (ABC) phenomenon, and this situation is referred as the "PEG dilemma". "PEG dilemma" posed severe challenges for the targeted delivery of PEGylated liposomes-loaded anticancer drugs, effective intracellular release of PEGylated PSL-encapsulated gene and protein drugs, and repeated administration of PEGylated liposomes. Therefore, it is urgent to solve the "PEG dilemma". This review focused on the definition, classification of "PEG dilemma", and discussed several possible approaches to overcome "PEG dilemma".
Antineoplastic Agents ; chemistry ; Drug Carriers ; chemistry ; Liposomes ; chemistry ; Polyethylene Glycols ; chemistry

Child, Preschool ; Humans ; Male ; Nevus, Blue ; pathology ; Skin Neoplasms ; pathology

Objective To investigate the characteristics of children′s recurrent abdominal pain(RAP) with gastroscopy and analyze the etiology.Methods Three hundred and thirteen children were investigated with gastroscopy.Gastric antrum mucosa was taken for histo-pathology and the determination of helicobacter pylori(Hp) antibody.Results Ninty-nine point six eight percent of the cases had lesions under the gastroscope.The former 4 cases had chronic superficial gastritis(CSG),CGS and bile reflux,CGS and duodenitis,CGS and bulb ulcer,and Hp infection rate was 31.36%,25%,38.64%,60.61%.Hp infection rates of active gastritis and inactive gastritis were 92% and 23.19%,which showed significant differences in 2 groups(P

ObjectiveTo investigate the CT number linearity of the cone-beam CT (CBCT) images at the different spatial locations in the scanning area.MethodsThe CatphanS04 phantom at the different locations are scanned repeatcdly using the CBCT on the Varian 23EX linear accelerator.The phantom is located the isocenter point,eccentric 3 cm,eccentric 6 cm,and different points on the z-axis successively on the accelerator.The scanned mode is the standard head mode.The reconstructive thickness is 2.5 cm.The different densities inserts of CTP404 module on the different locations are measured via Eclips treatment planning system (TPS) and computed by Matlab 7.0 and the CT linear fitting are then processed.In order to understand better the linear distribution along with the value of CT in the spatial distribution the results are compared with the fan-beam CT.ResultsPhantom studies show that:CBCT has good linearity performance not only under the standard header (body) of the scanning conditions,but also on such locations including the cross-sectional,the sagittal,the coronal plane and the eccentric position ( R2 ＞ 0.953 ).Bowtie filtration device does not change the CT finearity but changes the value of CT.ConclusionsThe linearity of X-ray CBCT on the Varian linear accelerator is favorable.CBCT will be used in the TPS dose calculation via further correction of the CT value.

Objective To evaluate the effect of home-made immobilization device with KV-CBCT in lung-SBRT and investigate its clinical use value.Methods Choosing 10 lung tumor patients (half centre type tumor;half peripheral type) random analysis the interfractional and intrafractional setup errors in the SBRT process by this fixed device with KV-CBCT.The concrete method is using Varian's KV-CBCT scans the patients before and after the SBRT each time,then make the registration between the reconstructed 3 d image and the planned CT image (both based on bone landmark),we then obtain the average setup errors in LR,AP and SI directions.Simultaneously,this research make contrastive analysis of setup errors among this fixed device and other fixed devices such as vacuum pad,phantom in body IMRT.All data make one-factor analysis of variance by SSPS 17.0.Results All the setup errors data was gaussian distribution,the centre type interfraction was at (0.01 ±0.32) cm (LR),(-0.08 ±0.38) cm (AP),(0.14 ±0.36) cm (SI) of the cross section,peripheral type interfraction was at (0.01 ± 0.32) cm (LR),(-0.08 ± 0.38) cm (AP),(0.14 ± 0.36) cm (SI) of the cross section (P =0.001).We found out that the average of lung tumor's setup error at all three directions have no significant difference-the largest was the AP directions (P =0.003),the second was the SI direction (P =0.003) and the smallest was the LR direction (P =0.001).The central type has no significant difference at three directions.Compare to the other fixed device,the average setup errors of our device are (0.09 ± 0.33) cm (LR),(-0.10 ± 0.44) cm (SI),(0.17 ±0.35) cm (AP) better than the report at present paper.As the interfraction setup error was small enough by using this fixed device while it has beyond the system algorithm,the registration software of system shows (0.0 ± 0.0 cm).Conclusions The range of lung tumor motion can be cut down obviously and enhance each placement accuracy,repeatability,on SBRT with home-made immobilization device.

Objective To study the effect of dialysis adcquacy,microinflammation and residual renal function on nutritional status of hemodialysis patients.Methods One hundred and fourteen patients were enrolled in this study.Kt/V,?_2-MG and serum iPTH were measured as markers of hemodialysis adequacy.Nutritional evaluation included MQSGA,Alb,Hb,TF,IGF-1,IGFBP-3 and anthropometrics such as HGS,BSF,TSF,MAC,MAMC and AMA.Serum IL-6,TNF-?and CRP were detected to assess microinflammation.Urinary volume of 24 hours was measured to investigate the residual renal function (RRF).Results (1)There were different correlations and regressive associations of Kt/V,iPTH and?_2-MG with HGS,MAMC,AMA,Alb,Hb,nPCR,IGF-1 and MQSGA respectively.(2) There were significant correlations and regressive associations of RRF to HGS,TSF,MAMC,Alb,nPCR and IGF-1 within the first year of hemodialysis.(3) There were different correlations and regression relationships of IL-6,TNF-?and CRP with HGS、MAMC、AMA、Alb、TSF、Hb、nPCR、IGF-1 respectively.(4) Multivariate analysis showed that Kt/V,iPTH,IL-6, TNF-?,?_2-MG and RRF were influencing factors,among them,Kt/V,iPTH,IL-6 and TNF-?were independent predictors of nutritional status.Conclusions Hemodialysis adequacy and micruinflammation may impact on nutritional status.Residual renal function may be involved in nutritional status in the first year of hemodialysis.Kt/V,iPTH,IL-6 and TNF-?are independent factors affecting nutritional status.

OBJECTIVEDouble-balloon enteroscopy is a new method that allows complete visualization of the lumen of small bowel. This study was conducted to evaluate safety, extent of observation and clinical efficacy of double-balloon push enteroscopy in diagnosis of patients with small bowel disease in children.

METHODSFourteen cases suspected of small bowel diseases with negative findings on examinations with various routine diagnostic modalities underwent double-balloon push enteroscopy from June, 2003 to May, 2005. Of the 14 cases, 13 had gastrointestinal bleeding and iron deficient anemia and 1 case had chronic diarrhea, the causes of these conditions were unknown.

RESULTSThe enteroscopy reached jejunal-ileum transitional area, middle or lower portion of ileum and terminal ileum in 2, 10 and 2 cases, and the examination time was 40-50 min, 55-70 min and 78-89 min, respectively. Lesions were detected in 12 of 14 the cases. The positive diagnostic rate was 85.7%. There were no relevant technical problems or severe complications.

CONCLUSIONDouble-balloon push enteroscopy is a safe, reliable diagnostic modality of high clinical value for small bowel diseases in children.

Adolescent ; Anemia, Iron-Deficiency ; diagnosis ; etiology ; Catheterization ; instrumentation ; methods ; Child ; Child, Preschool ; Diagnosis, Differential ; Diarrhea ; etiology ; Endoscopes, Gastrointestinal ; adverse effects ; Endoscopy, Gastrointestinal ; adverse effects ; methods ; Female ; Gastrointestinal Hemorrhage ; diagnosis ; etiology ; Humans ; Intestinal Diseases ; complications ; diagnosis ; etiology ; pathology ; Intestine, Small ; pathology ; Male

OBJECTIVEEndoscopic sclerotherapy has emerged as an effective treatment for bleeding esophageal varices in adults and children but the long-term outcome is poorly defined in children. The present study aimed to study the long-term effect of endoscopic sclerotherapy in children with portal hypertension.

METHODSFifteen patients (age 3 to 14 years) with esophageal variceal bleeding underwent endoscopic injection treatments with 1% Aethoxy-sclerol since 1996. All subjects continued to receive the therapy by repeated intra and extravariceal endoscopic sclerotherapy at intervals of 3 - 4 weeks until the varices disappeared, and received regular endoscopic follow-up.

RESULTSFifteen patients had totally 43 injections, and were followed up from 40 to 86 months (mean 66 months) by endoscopy. Two patients received 2 injections and 5 received 3 before eradication of varices. The mean time needed for varices eradication was 3 to 6 months. Recurrence of varices and bleeding was seen in 3 patients who had duodenal ulcer.

CONCLUSIONEndoscopic sclerotherapy is a safe and effective treatment for pediatric esophageal varices.

Adolescent ; Child ; Child, Preschool ; Duodenal Ulcer ; complications ; Esophageal and Gastric Varices ; etiology ; therapy ; Esophagoscopy ; Gastrointestinal Hemorrhage ; etiology ; therapy ; Humans ; Hypertension, Portal ; complications ; Injections, Intralesional ; Polyethylene Glycols ; administration & dosage ; Recurrence ; Reoperation ; Sclerosing Solutions ; administration & dosage ; Sclerotherapy ; Time Factors ; Treatment Outcome

OBJECTIVEWith the development of endoscopic therapy in children, endoscopic electrocoagulation polypectomy had gradually replaced surgery and became an important method to resect gastrointestinal polyps in children. Simple electrocoagulation polypectomy could often bring some complications of gastrointestinal bleeding and perforation because of incomplete electrocoagulation or mechanical incision, especially in gastrointestinal thick-pedunculated polyps which always have thick nutrient blood vessel. Hemoclips can successfully interdict arteriovenous blood because it can clamp tissue firmly without causing necrosis around the target area. Based on its good mechanical hemostasis, hemoclips are not only widely used in treating bleeding like from ulcer, tumor and variceal ligation but also used in removal of thick-pedunculated gastrointestinal polyps in adults. This paper describes the application of endoscopic electrocoagulation with metal hemoclips to remove thick-pedunculated intestinal polpys in children for the first time, sums up the experience and evaluates its efficacy and safety.

METHODSBetween October, 2001 and December, 2002, 5 cases with thick-pedunculated intestinal polpys were presented. The age of the patients ranged from 3 to 5 years. The clinical features were gastrointestinal bleeding or abdominal pain. The longest course of disease was 2 years. Enough preparations for alimentary tract were necessary for polypectomy. The procedures were performed under general anesthesia in order to avoid the risk of bleeding aspiration. Endoscopy was performed in the standard fashion. The apparatus included electronic colonic endoscope (XQ 200, Fuji Corp, Tokyo, Japan), snare (XQ200, Fuji Corp, Tokyo, Japan), impeller of the clip (HX-5QR-1) and hemoclip (MD850) which could be passed through the biopsy channel of endoscope. The clip was completely covered with a hood avoiding any injury to the mucous membrane. The pedicel with diameter of more than 1.0 cm underwent endoscopic electrocoagulation polypectomy with hemoclips. The clip contacted polyps in upright direction. One or more hemoclips were selected to clamp the proximal basement of the pedicel in terms of the pedicel diameter. Turning of the red colour of polyps to purple suggested that hemoclip interdicted arteriovenous blood effectively. The clip was then shut off and electrocoagulation polypectomy was followed. Six polyps were observed and removed.

RESULTSSix polyps including 2 transverse colon polyps and 4 descending colon polyps were resected. Pathological results showed that 3 were juvenile polyps and the other 3 adenomatous polyps. All the polyps were completely resected. The diameter of pedicel were 1.2 - 2.2 cm. The head and pedicel of the biggest polyp was about 5 cm x 5 cm and 2.2 cm, respectively, and five clips were used in order to remove it. No complications of bleeding and perforation were observed in these children. All hemoclips were expelled from intestines within one week. The symptoms of these patients disappeared.

CONCLUSIONMechanical hemostasis with hemoclips successfully interdicted arteriovenous blood of thick-pedunculated polyps. Hemoclips can successfully prevent the complications of bleeding and perforation. The clipping brings about a new method in endoscopic therapy. Endoscopic electrocoagulation polypectomy with hemoclips is a simple, safe and effective method to treat thick-pedunculated gastrointestinal polyps in children and it is a valuable tool in polypectomy for children.

Child ; Child, Preschool ; Endoscopy ; methods ; Humans ; Intestinal Polyps ; surgery ; Surgical Instruments ; Treatment Outcome

Objective To determine the changes of cerebrospinal fluid(CSF) ?-endorphin(?-EP) and C-reactive protein(CRP) in children with central nervous system(CNS) infection.Methods Sixty-five children suffered from CNS infection were determined the plasma and CSF ?-EP and CRP concentration during the acute and recovering stage with radioimmunoassay, which included 48 viral encephalitis, 12 purulent meningitis and 5 tuberculou meningitis,and 24 non-CNS disease children were as control group.Results The concentrations of plasma and CSF ?-EP of every experimental group were obviously higher than those of control group during the early stage of CNS infection and these were obviously lower during the recovering stage. The serum concentration of CRP during acute stage was significantly higher than that during recovering stage. No change of serum and CSF CRP concentration was determined during either the acute or recovering stage in the other two experimental groups.Conclusions Determining the plasma and CSF ?-EP is mea-(ningful) in early diagnosis of CNS infection,and determining the serum CRP at the same time may be helpful in differentiating septic and inseptic infection.