OBJECTIVE To investigate and analyze the kinetics of serological marks and virus load of the follow-up blood donors. METHODS The quantitation of HBV DNA of 6 HBsAg negative and DNA positive blood donors was detected by Roche PCR Monitor,and the donors were genotyped and traced by serological tests. RESULTS(Three of 6 follow-up) donor samples were seroconverted after more than 40 days follow-up study.The viral loads were with range of(35-1.8)?10~4 copies/ml,1 of 6 donors had acute infection,the peak load was(1.8?10~4 copies/ml),3 of 6 were with lower level HBV carrier with fluctuating viral load ranged 100-500 copies/ml.One donor had decreasing viral load,when HBsAg converted to positive,virus wasn′t detected.The last one had fluctuating virus load below(100 copies/ml),intermittently falling below the threshold of the assay. CONCLUSIONS It is necessary to implement HBV DNA detection for blood screening,and further strengthen the safety of blood transfusion.

0.05).However,during the thawing process of the APCs,four out of ten and three out of eleven APCs samples appeared aggregative reaction after cryo-preservance for 4 and 5 years,respectively.The majority of the samples extensively lost their factor Ⅲ activities in the fifth year storage.When fresh,liquid platelets were stored at room temperature(22 ℃),the in vitro adhesion and agglutination gradually decreased and statistic differences were observed in 72 h(P

SCLC can spare more volume of the normal lungs and e-sophagus, and has the ability of dose escalation.

Objective To investigate the prevalence of nutritional risk,malnutrition(undemutrition),overweight/obesity,and application of nutritional support in hospitalized patients with endocrine disorders.Methods Adult patients in Department of Endocrine of Peking Union Medical College Hospital(PUMCH)from September to December 2008 were consecutively enrolled.Nutrional Risk Screening 2002(NRS2002)war per-formed on the next morning after admission and nutritional support evaluation was performed on the 14th day of ad-mission or on the discharge day.The relationship between nutritional risk and nutritional support Was analyzed.Nu-tritional risk was defined as NRS2002 score≥3,and body mass index(BMI)<18.5 ks/m2 defined as unclernut-rition.Results A total of 152 patients were enroled,and NBS2002 scoring was performed in all patients.The prevalence of undernutrition Was 7.9%and the nutritional risk was 27.6%.The prevalence of nutritional risk in the elderly inpotients(≥60 years old)was significantly higher than in younger patients(18-59 years old)(36.8%vs 20.2%,P=O.023).Nine patients(21.4%)with NRS2002≥3 received nutrition support,and 12patients(10.9%)with NRS2002<3 received nutritional support.The average PN:EN ratio was 1:3.2.Conclu-siom NRS2002 is afeasible nutritional risk screening tool for inpatients with endocrine disorders.A large propor-tion of inpotients were at nutritional risk or undemutrition in the Department of Endocrine of PUMCH. The application of nutritional support currently is somehow inappropriate.Evidence-based guidelines are required to improve this situation

Objective To quantitatively analyze the image quality of megavoltage cone-beam CT (MVCBCT) under different scanning conditions to provide reference in clinical applications. Methods Si-emens ONCOR linear accelerator with MVCBCT was used to scan the phantom under different conditions. The image quality was evaluated in terms of image noise, uniformity, spatial resolution, contrast resolution, the number of Monitor Units(MUs) used in imaging,and the size of the reconstruction matrix. The comparison of the image quality between MVCBCT and conventional simulator CT was also analyzed. Results The image noise was decreased with the increase of the number of MUs. The uniformity index showed that the system u-niformity was weakly dependent on MU numbers or the size of the reconstruction matrix. Except for the ima-ges with 5 MUs,all other images had the spatial resolution of 0.4 lp/mm with a reconstruction matrix of 256 ×256. Better low contrast resolution was achieved by using more MUs. For typical pelvis and head-and-neck patients,the imaging dose at the center was 0.8 cGy/MU and 0.7 cGy/MU, respectively,and the maxi-mum dose was about 1.2 cGy/MU. For typical abdomen patients,the image maximum dose and center dose was 1.3 cGy/MU and 0.7 cGy/MU,respectively. Conclusions The image quality of MVCBCT is inferior to the conventional kilo-voltage CT. However,with the optimization of the parameters in imaging,we can a-chieve sufficient image contrast in the bone,air and some soft-tissue structures with low imaging dose to pa-tients. Such images can be used for IGRT.

Objective To analysis the genomic sequence of a novel human leukocyte antigen (HLA)-B*3818 allele.Methods Full length genomic sequence of an unknown HLA-B allele was cloned,followed by bi-directional sequencing and the specificity of the antigen coded by this novel allele was defined by microcytotoxicity assay.The frequency and haplotype of this novel allele was acquired by population census and parentage analysis.Results The full length genomic sequence of this novel HLA-B*3818 allele with accession number FJ561482 differs from HLA-B*380201 by two nucleotide changes in exon 4 and intron 5,respectively.One change is located at nt 660 in exon 4 where C→A alternation,which results in an amino acid substitution from Asp(GAC)to Glu(GAA)at codon 196.This alternation is a new single nucleotide polymorphism compared with all other HLA-B alleles.Another is located at genomic position 2133 in intron 5(A→C).Except for this substitution,the intron sequences of HLA-B*3818 allele are identical to those of other HLA-B*38 alleles including HLA-B*380101,B*380201 and B*3814.The serological specificity of HLA-B*3818 is B38 and the frequency of this new allele is less than 0.000 5 in Chinese Han population.The parentage analysis showed the haplotype of novel allele is A*030101-Cw*010201-B*3818-DRB1*1312-DOB1*060101.Conclusion The simultaneous mutations in exon and intron were found in the Hovel HLA-B*3818 allele,and so it can present more sequence information for studies and applications associated with HIA genes by analyzing the genomic sequences of novel HLA alleles.

Objective To compare the dose distribution of the target and normal tissues in gastric cancers between three-dimension conformal radiation therapy (3DCRT) and intensity modulated radiation therapy (IMRT) plan when respiratory motion factors integrated in the plan. Methods From January 2005to November 2006, 10 patients with post-operatively radiation of gastric cancer were enrolled in this study.Planning CT were acquired conventionally with free-breath mode and the static treatment plans of the 3DCRT and IMRT were designed respectively. Probability distribution functions (PDF) were generated and convoluted with the static dose distributions from 3DCRT and IMRT plans to obtain the integrated plans. The dose distributions of the target and normal tissues were compared between 3DCRT and IMRT integration treatment plans, such as V45 of clinical target volume, V4o of liver and V15, V18 of left and right kidney.Results In the respiratory integrated treatment planning, the target volume coverage and homogeneity with IMRT are superior to those with 3DCRT ( ( V45 98%∶ 87% (t = -3. 35 ,P =0. 010) ,mean dose 46. 81 Gy ±0. 75 Gy∶45.99 Gy ± 1.12 Gy (t = -0. 31 ,P=0. 020) ). The V40 of teh liver in IMRT are smaller than those in 3DCRT ( 12%∶ 16% ;t=3.75,P=0.010). For the left kidney, the V15 and V18 in IMRT are smaller than those in 3DCRT ( (34%∶ 50% (t = 2. 17 ,P = 0. 050) and 27%∶46% (t = 3. 11 ,P = 0. 020) ),but for the right kidney, V15 and V18 in 3DCRT are smaller than those in IMRT ( ( 15%∶ 21% (t = - 2. 42,P=0.040) and 11%∶15% (t= -2.71,P=0.030)). Conclusions When respiratory motion factor integrated in the treatment plan, IMRT showed advantage both in target coverage and normal tissue sparing in the high dose region of liver and left kidney.

Objective To evaluate set-up errors by megavoltage cone-beam CT in head and neck cancers treated with precision radiotherapy. Methods From April 2007 to March 2008, 22 patients with nasopharyngeal carcinoma (15 patients) ,parotid carcinoma (4 patients) and brain glioma (3 patients) were enrolled, among whom 7 patients underwent three-dimensional conformal radiotherapy (3DCRT) and 15 received intensity modulated radiotherapy (IMRT). The radiation dose was 56. 0 -70.4 Gy in 28 -32 fractions within 6 -7 weeks. Megavoltage cone-beam scan was performed weekly before treatment. The isocenter displacement was calculated by comparing megavoltage cone-beam CT and planning CT in left-right (LR), cranio-caudal (CC), and anterior-posterior (AP) directions. Results Totally 129 sets of megavoltage cone-beam CT images were obtained for 22 patients. The frequency of isocenter shift more than 0. 3 cm,0. 4 cm and 0. 5 cm were 28,15 and 9, respectively. The maximum mean set-up error was found in CC, which was about 0. 1 cm more than that in LR and AP. The frequency of isocenter shift direction was almost identical in LR and CC, which was more frequent (about 75%) in the posterior direction. Conclusions During the course of radiation of brain tumor and head and neck cancer, the enlarging tendency of set-up errors has been found in all the three directions. The isocenter shift in AP was more frequent to the posterior direction.

Objective To assess the impact of respiratory motion on the displacement of target area and to analyze the discrimination between free breathing and active breathing control (ABC) in patients with gastric cancer treated with post-operative radiotherapy. Methods From January 2005 to November 2006, 22 patients with post-operatively confirmed gastric cancer were enrolled in this study. All diseases were T_3/ N +, staging Ⅱ - Ⅳ. Patients were CT scanned and treated by radiation with the use of ABC. Image J software was used in image processing, motion measurement and data analysis. Surgical clips were implanted as fiducial marks in the tumor bed and lymphatic drainage area. The motion range of each clip was measured in the resultant-projection image. Motions of the clips in superior-inferior (S-I), right-left (R-L) and anterior-posterior (A-P) directions were determined from fluoroscopy movies obtained in the treatment position. Results The motion ranges in S-I, R-L and A-P directions were 11.1 mam, 1.9 mm and 2.5 mm (F = 85.15, P = 0. 000) under free breathing, with 2.2 mm, 1.1 mm and 1.7 nun under ABC (F = 17.64, P = 0. 000), and the reduction of motion ranges was significant in both S-I and A-P directions (t = 4.36, P = 0. 000;t = 3.73,P = 0.000). When compared with under free-breathing, the motion ranges under ABC were kept unchanged in the same breathing phase of the same treatment fraction, while significant increased in different breathing phase in all three directions (t = - 4.36, P = 0. 000; t = - 3.52, P = 0.000; t =-3.79, P = 0. 000), with a numerical value of 3.7 mm, 1.6 mm and 2.8 mm, respectively (F = 19.46, P = 0. 000) . With ABC between different treatment fractions , the maximum displacements were 2.7 mm, 1.7 mm and 2.5 mm for the centre of the clip cluster (F =4.07,P =0. 019), and were 4.6 mm, 3.1 mm and 4.2 mm for the clips (F =5.17 ,P =0.007). The motion ranges were significant increased in all the three directions (t = - 4.09, P=0.000 ; t =-4.46, P = 0.000 ; t = - 3.45, P =0.000). Conclusions In the irradiation of post-operative gastric cancer, the maximum displacement of organ motions induced by respiration is in S-1 direction and the minimum in R-L direction under free breathing. The use of ABC can reduce the motions significantly in S-I and A-P directions, and the same changes exist in both inter-and intra-fraction treatment.

Objective To investigate whether the change of beam set-up methods will influence the dosimetric quality of intensity modulated radiation therapy (IMRT) for non-small cell lung cancer (NSCLC).Methods Twenty-one stage Ⅰ-Ⅲ NSCLC patients were selected for this study.The technique of step and shoot was used and three different beam set-up methods were chosen for IMRT planning,including IMRT-7 with nine equal-spaced beams angled 0°,51°,102°,153°,204°,255°and 306°; IMRT-5 with five equal-spaced beams angled 0°,72°,144°,216°and 288°; and IMRT-5m which was created from IMRT-7 but excluded 2 fields (51°and 102° were omitted if there was lesion in the right lung,while 255°and 306° were excluded if there was lesion in the left lung).The dose constrains ofnormal lungs for IMRT were set according to V5-V60 of normal lungs obtained from the same patient's actually treated 3D-CRT dose volume histogram.The prescription dose for IMRT started from 65 Gy,and then escalated or decreased step by step by 2 Gy once a time until the best plan was obtained.Results For normal lung dose,IMRT-5m had lower V5-V25 than the other two groups; but there was no significant difference in V30-V40.IMRT-5 was the worst for V45-V60; and mean lung dose was lowest in IMRT-5m.Dose parameters of esophagus and spinal cord,target conformity index,and total monitor units were all similar among difference plans.IMRT-5m had lowest heart V40 compared to the other two groups.For target heterogeneity index,IMRT-5 was higher than IMRT-7,but there were no significant differences among IMRT-5m,IMRT-5 and IMRT-7.Compared to 3D-CRT,the prescription dose could be increased by (5.1 ±4.6) Gy for IMRT-7,(3.1 ±5.3) Gy for IMRT-5,and (5.5 ±4.8)Gy for IMRT-5m.Conclusion Fewer beams and modified beam angles could result in similar,even better plan quality.