In the present work, Monte Carlo simulations were employed to study the characteristics of the dose distribution of high energy electron beam in the presence of uniform transverse magnetic field. The simulations carried out the transport processes of the 30 MeV electron beam in the homogeneous water phantom with different magnetic field. It was found that the dose distribution of the 30 MeV electron beam had changed significantly because of the magnetic field. The result showed that the range of the electron beam was decreased obviously and it formed a very high dose peak at the end of the range, and the ratio of maximum dose to the dose of the surface was greatly increased. The results of this study demonstrated that we could change the depth dose distribution of electron beam which is analogous to the heavy ion by modulating the energy of the electron and magnetic field. It means that using magnetic fields in conjunction with electron radiation therapy has great application prospect, but it also has brought new challenges for the research of dose algorithm.
Algorithms ; Electrons ; Humans ; Magnetic Fields ; Monte Carlo Method ; Phantoms, Imaging ; Radiation Dosage

Objective To explore the effect of dimethylformamide(DMF)on the histological structure and enzymes activity in the testis of mice.Methods The KM male mice were treated with DMF by gavage at the doses of 0,0.5,1 and 2 g/kg respectively, once a day,for 30 consecutive days.On day 31,the mice blood samples were collected through eyes and then the mice were killed. Two mice were randomly selected in each group and one testicle was sampled to do the pathological examination,the other one for enzyme activity determination,including succinic acid dehydrogenase(SDH),lactate dehydrogenase(LDH)and acid phosphatase (ACP).Results Compared with the control group,all treated groups showed a significant decrease in body weight(P

Objective To evaluate the clinical effect of surgical operation for recovering the function of ulnar nerve with large segment defect. Methods Twentycases with the large segment defect of ulnar nerve were retrospectively analyzed from September 1999 to December 2006 in the hospital.All the patients were treated by the operation of nerve end-to-side neurorrhaphy . The broken end of ulnar nerve was anastomosed with the median nerve. And observed the recovery of the sensation and motion function of the little finger, interosseous muscles and claw hand, then compared with before. Results All cases were followed up for 8 to 36 months. The mean was 16 months. The sensation and motion function of the little fingers had better restoration after operation. No incision infection, anchylosis or myatrophy was occurred.Excellent(M4 + S4 +) ,Good (M3S3), moderate (M2S2), and poor effects (M1S1) were achieved respectively in 6, 4,2 and 0 cases based on the scale of XU' s grading standard.The excellent and good rate was 83.3%. Conclusion The nerve end-to-side neurorrhaphy was a effective treatment for the patients with large segment defect of ulnar nerve.

The hybrid pencil beam model (HPBM) is an effective algorithm for calculating electron dose distribution in radiotherapy. The mean energy distribution of incident electron beam in phantom is one of the factors that affect the calculation accuracy of HPBM, especially in field edge areas near the end of the electron range. A new fitted formula based on Monte Carlo (MC) simulation data for electron beams with energy range of 6-20 MeV in the homogeneous water phantom is proposed in this paper. The precision of the fitted formula within the scope of the energy was evaluated by comparing the electron dose distribution of ECWG measured data with that obtained from HPBM which took the mean electron energy that calculated by the fitted formula and the existed empirical formula, respectively. The results showed that the accuracy of dose distribution that obtained by the mean electron energy calculated with the fitted formula increased about 1%.
Algorithms ; Electrons ; Humans ; Monte Carlo Method ; Phantoms, Imaging ; Radiotherapy Planning, Computer-Assisted ; Water

Objective To investigate the prevalence of latent tuberculosis infection(LTBI),and to identify the risk factors in primary schoolchildren from Shanghai through the population-based field investigation combined with the tuberculosis infection enzyme-linked immunospot assay(T-SPOT.TB)assay.Methods The children in grade 4 and 5 were enrolled from four primary schools in Pudong new district and Yangpu district of Shanghai.Questionnaire interview was applied to investigate the soeiodemographic and clinical information related to LTBI.The T-SPOT.TB assay was used to detect LTBI in the enrolled subjects.Univaitate and multivariate analyses were used to identify the risk factors associated with LTBI among the primary schoolchildren.Results Totally 472 schoolchildren were enrolled in the present study,with 439(93.0%)being vaccinated with bacillus calmette-guerin (BCG) and ten (2.1%) having contact history with tuberculosis (TB) patients.Among the 472 eligible subjects,16(3.4%) children were T-SPOT.TB positive,who had no clinical symptoms andsigns relevant to TB and were defined as LTBI.The LTBI prevalence in BCG vaccinated and unvaccinated children were 2.7% and 12.1%,respectively (OR:6.972;95%CI:1.834-26.500);those in TB contacts and children without TB contact history were 30.0% and 2.8%, respectively (OR: 16. 38; 95% CI: 3. 692-72. 700). Conclusions The prevalence of LTBI among senior schoolchildren in Shanghai is 3.4%. BCG vaccination is protective for children from LTBI, while daily contacts with TB patients increases the risk of LTBI in schoolchildren.

This study tested the effects of the gastrointestinal pulse train electrical stimulation with different parameters and at different locations on the neuronal activities of the lateral hypothalamus area (LHA) in obese rats in order to find the optimal stimulation parameter and location. Eight gastric electrical stimulations (GES) with different parameters were performed and the neuronal activities of gastric-distension responsive (GD-R) neurons in LHA were observed. The effects of stimulations with 8 parameters were compared to find the optimal parameter. Then the optimal parameter was used to perform electrical stimulation at duodenum and ileum, and the effects of the duodenal and ileac stimulation on the GD-R neurons in LHA were compared with the gastric stimulation of optimal parameter. The results showed that GES with the lowest energy parameter (0.3 ms, 3 mA, 20 Hz, 2 s on, 3 s off) activated the least neurons. The effects of GES with other parameters whose pulse width was 0.3 ms were not significantly different from those of the lowest energy parameter. Most gastric stimulations whose pulse width was 3 ms activated more LHA neurons than the smallest energy parameter stimulation, and the effects of those 3 ms gastric stimulations were similar. Accordingly, the lowest energy parameter was recognized as the optimal parameter. The effects of stimulations with the optimal parameter at stomach, duodenum and ileum on the LHA neuronal activities were not different. Collectively, gastrointestinal electrical stimulation (GIES) with relatively large pulse width might have stronger effects to the neuronal activities of GD-R neurons in LHA of obese rats. The effects of the GIES at different locations (stomach, duodenum and ileum) on those neurons are similar, and GES is preferential because of its easy clinical performance and safety.

Objective Measurement of ankle brachial index (ABI) is a simple method of assessing lower limb arterial blood supply,while measurement of toe brachial index (TBI)has only been advocated as an alternative.The aim of this study was to obtain information about whether TBI should be taken in type 2 diabetes,even when ABI is normal,and to evaluate the relationship between TBI and atherosclerosis.Methods In a crosssection study,ABI,TBI,and carotid intimal-medial thickness (IMT) were measured on 979 outpatients with type 2 diabetes in Ruijin Hospital.Those with normal ABI (0.9 ≤ABI ＜ 1.3,n = 945) were divided into two groupsnormal TBI group(TBI≥0.6,n=893) and low TBI group(TBI＜0.6,n=52),and then the clinical and laboratory data were compared between these two groups.Furthermore,the relationship between TBI and atherosclerosis was investigated.Atherosclerosis was defined as the maximum IMT ≥ 1.1 mm.Results Low ABI and low TBI were detected in 1.3% and 6.6% of the patients,respectively.Comparison of the clinical and laboratory data between the two groups showed that age and HbA1C values were significantly higher in the low TBI group.Furthermore,TBI was inversely associated with IMT(β=-0.217,P＜0.01),an indicator for atherosclerosis of the carotid artery.Multiple logistic regression analysis revealed that decline of TBI was an independent risk factor of atherosclerosis (OR=1.30,95% CI 1.01-1.69,P＜0.05).Conclusion In type 2 diabetes,the decline of TBI is associated with atherosclerosis,indicating the necessity for diabetic patients to detect TBI,even when ABI is within normal range,in order to detect peripheral artery disease in early stage,and reduce the risk for atherosclerosis.

OBJECTIVE: Mitochondrial deoxyribonucleic acid (mtDNA) 8344 A>G (m.8344A>G) mutation is the common mutation associated with mitochondrial myoclonus epilepsy with ragged-red fibers (MERRF) syndrome. Herein we report a rare case with mitochondrial encephalopathy, lactic acidosis and stroke-like episodes/MERRF/Leigh (MELAS/MERRF/Leigh) overlap syndrome caused by m.8344A>G mutation. METHODS: The clinical and imaging data of the patient were collected and an open muscle biopsy was carried out. We further employed molecular genetic analyses to detect mtDNA mutation in the proband and his mother. And then a clinical and neuroimaging follow-up was performed. RESULTS: This patient was a 25-year-old male, who developed exercise intolerance since the age of 6. At age 10, he suffered from acute episodes of hemianopia, and cranial magnetic resonance imaging (MRI) showed occipital stroke-like lesions and cranial magnetic resonance spectroscopy (MRS) revealed a lactate peak corresponding to the lesion. After that the patient presented slowly progressive psychomotor decline. He had myoclonic seizures and cerebellar ataxia since the age of 12. At age 21, he was admitted to our hospital because of confusion and cranial MRI revealed symmetrical lesions in bilateral posterior putamen, thalami and midbrain. Then repeated MRI showed progression of original lesions and new frontal multiple stroke-like lesions. Symptomatic and rehabilitation treatment relieved his condition. Follow-up cranial MRI at age 24 showed the lesions in basal ganglia and thalami diminished, and the midbrain lesions even completely vanished. Muscle pathology indicated the presence of numerous scattered ragged-red fibers (RRF), suggestive of a mitochondrial disorder. Polymerase chain reaction-restricted fragment length polymorphism (PCR-RFLP) detected the m.8344A>G mutation of the MT-TK gene encoding mitochondrial transfer RNA for lysine in the patient's blood. Next generation sequencing (NGS) of the whole mitochondrial genome identified that the proportion of m.8344A>G was 90%, and no other mtDNA mutation was detected. Sanger sequencing further identified this mutation both in the proband and his mother's blood, although the mutation load was much lower in his mother's blood with approximately 10% heteroplasmy. CONCLUSION The present study is the first to describe a patient with m.8344A>G mutation in association with the MELAS/MERRF/Leigh overlap syndrome, which expands the phenotypic spectrum of the m.8344A>G mutation.
Acidosis, Lactic ; Adult ; Child ; DNA, Mitochondrial/genetics* ; Humans ; Male ; Mitochondrial Encephalomyopathies ; Mutation ; Stroke ; Young Adult

Adolescent ; Adult ; Antigens, CD34 ; metabolism ; Antineoplastic Agents ; therapeutic use ; Benzamides ; Chondroma ; drug therapy ; metabolism ; pathology ; surgery ; Female ; Follow-Up Studies ; Gastrectomy ; Gastrointestinal Stromal Tumors ; drug therapy ; metabolism ; pathology ; surgery ; Humans ; Imatinib Mesylate ; Lung Neoplasms ; drug therapy ; metabolism ; pathology ; surgery ; Neoplasm Recurrence, Local ; Neoplasms, Multiple Primary ; drug therapy ; metabolism ; pathology ; surgery ; Piperazines ; therapeutic use ; Pneumonectomy ; Proto-Oncogene Proteins c-kit ; metabolism ; Pyrimidines ; therapeutic use

Objective:To investigate the expression of annexin 5 in rat testis after removing submandibular gland in rats. Methods:On day 14,28 and 42 after the operation,the changes of annexin 5 expression in rat testis were analyzed by Western blot and Immunohistochemistry.Results:Western blot showed that there was a 27.5% and a 35.2% significant increase(P