基于物体空间序法的CT图像三维重建算法的研究

首先对三维可视化方法进行了分类概述。接着对基本的物体空间序法及其改进算法——抛雪球法做了详细的描述，并且通过对两组CT数据进行三维重建实验，得到高质量的重构图像。最后，本文研究并采用了提取表面体素进行体绘制加速的方法，实现了基于等值面提取表面的加速算法，实验证明加速算法能够满足显示要求并能起到明显的加速作用。     

Risk factors associated with having psoriatic arthritis in patients with cutaneous psoriasis

The aim of this study was to determine if the following characteristics were associated with the presence of psoriatic arthritis in a sample of psoriasis patients: race, family history of psoriasis and psoriatic arthritis, age of onset of psoriasis, smoking, alcohol consumption and the maximum body surface area (BSA) affected by psoriasis. This was a case–control study involving 400 psoriasis patients who attended the Psoriasis and Photo‐medicine clinic in the National Skin Center of Singapore over a 1‐year period. Cases were psoriasis patients with psoriatic arthritis while controls were psoriasis patients without psoriatic arthritis. The diagnosis of psoriatic arthritis was made by rheumatologists and participants completed a self‐administered standardized questionnaire. The maximum BSA involved was determined from the case notes. Psoriatic arthritis was not significantly associated with sex, race, age of onset of psoriasis, a family history of psoriasis, smoking and alcohol consumption but was significantly associated with a family history of psoriatic arthritis (P < 0.001) and the maximum body surface involved (P = 0.05). Using multivariate analysis to control for variables, the presence of psoriatic arthritis was significantly associated with a family history of psoriatic arthritis (odds ratio [OR] = 20.5; 95% confidence interval [CI] = 2.49–169.10) and the maximum BSA involved (OR = 2.52; 95% CI = 1.33–4.75). Indian psoriatic patients were more likely to have psoriatic arthritis compared to the other races. A family history of psoriatic arthritis and a greater maximum body surface involved may be associated with having psoriatic arthritis in this study population of psoriasis patients.     

Transient synovitis of the hip in children: role of US

Transient synovitis of the hip remains a common diagnostic problem for the clinician. The physical signs are not pathognomonic of the condition, and the classic technical examinations are of little help. Therefore, the authors retrospectively studied the value of hip arthrosonography in 46 children with clinical symptoms suggesting pathologic hip conditions. In 20 of the 21 patients with a final diagnosis of transient synovitis, articular effusion was detected on ultrasound (US). Conventional radiography showed an increased medial joint space in only eight of these patients. Increased echogenicity of the articular fluid was found in both transient synovitis and septic arthritis. The high sensitivity of US in detecting intraarticular fluid was demonstrated by cadaver studies.     

Iron supplementation in female blood donors deferred by copper sulfate screening

Female blood donors with low hematocrit levels detected by copper sulfate screening were selected randomly to receive either 75 mg of iron per day, as ferrous gluconate, or a calcium phosphate placebo. Their ferritin, serum iron, total iron-binding capacity, zinc protoporphyrin, and hemoglobin values, as well as their suitability to donate blood, were determined initially (Visit 1) and at four follow-up visits (Visits 2-5). By the second visit, the serum ferritin and iron values of donors receiving iron supplementation differed significantly from those of donors receiving placebo. By the fifth visit, a less marked but significant increase in hemoglobin had occurred in the iron group, but not in the placebo group. At no time was there a significant difference between the groups' suitability to donate blood, with each group donating at almost half of their visits. The authors conclude that iron supplementation at this dose level in deferred female blood donors improves their iron status and hemoglobin levels, but does not significantly increase their suitability to donate blood as compared with the suitability of placebo-treated donors.     

Total radical trapping antioxidant potential (TRAP) and exercise

The relationship between physical activity, physical fitness and total radical trapping antioxidant potential (TRAP) was examined in the Northern Ireland Health and Activity Survey. This was a cross-sectional population study (n = 1600) using a two-stage probability sample of the population. TRAP was calculated using the sum of the individual serum antioxidant concentrations (urate, protein thiols, ascorbate, alpha tocopherol and bilirubin) multiplied by their respective stoichiometric values. Physical fitness was determined by estimation of VO2max by extrapolation from submaximal oxygen uptake, and physical activity was recorded by computer-assisted interview. Mean serum TRAP concentrations were significantly higher in males (653 +/- 8.2 mumol/l, mean +/- SEM) compared to females (564 +/- 8.0 mumol/l) (p < 0.0001). Both male and female smokers had significantly lower TRAP values than non-smokers (males p < 0.0001, females p = 0.02). In females, there was a positive relationship of TRAP with age (p < 0.001) and body mass index (p < 0.001) but a negative relationship with physical fitness (p < 0.05). The known beneficial effects of exercise and activity do not appear to be directly mediated through increased antioxidant status.      

15The effect of Lower Esophageal Sphincter (LES) electrical stimulation on LES pressure

Background: Electrical stimulation (ES) of the stomach has been shown to modulate LESP. Electrical stimulation, using neural high frequency stimulation (NGES) can induce contractions of the smooth muscle of the gut. The purpose of this study was to determine if electrical stimulation of the LES can affect LESP. Methods: Four female hound dogs, weight: 20–25 kg, underwent an esophagostomy that allowed the introduction of a sleeve manometry catheter into the esophagus. They were also implanted with a pair of electrodes along the longitudinal axis of the LES. After 3 weeks of recovery, they underwent esophageal manometry recording during control and ES, performed randomly on separate days, using 4 different stimulations: 1‐Low frequency: freq: 6 cycles/min, pulse: 350 milisec, amp: 5 mAmp; 2 High‐frequency: freq: 50 Hz, pulse: 1 milisec, amp: 5 mAmp; 3‐ NGES: freq: 50 Hz, pulse:20 milisec, amp:10 volts; 4‐ High‐frequency, circular: freq: 20 Hz, pulse:1 milisec, amp:5 mAmp. All recordings were performed 1 hour after consumption of 3 ounces of canned dog food, to prevent fluctuations in LESP and under mild sedation (acepromazine 0.5 mg kg^­1). Tests consisted, during ES days, of 3 periods of 20 minutes each: control , stimulation and post stimulation. The effect of NGES was also tested under anesthesia and following administration of L‐NAME 50 mg kg^­1 IV. and also atropine 0.05 mg kg^­1 IV. Analysis: area under the curve (AUC) and pressure were compared among the 3 periods. Data shown as mean ± SD, ANOVA and t‐test, p < 0.05. Results: Sustained increase in LESP was observed during low frequency stimulation, 32.1 ± 12.8 vs. 42.4 ± 18.0 vs. 50.1 ± 23.6, control vs. stimulation vs. post stimulation respectively, p = 0.013. AUC also significantly increased during and after stimulation, 39,320.3 ± 15,722 vs. 51,294 ± 21,826 vs. 59,823.6 ± 28,198.4 mmHgxsec, control vs. stimulation vs. post stimulation respectively, p = 0.01. There was no significant change with other types of ES. NGES induced an initial rise in LESP followed within few seconds by relaxation with slow resumption of pressure over a 1 minute period. L‐NAME increased LESP and augmented the initial rise in LESP following NGES but markedly diminished or abolished the relaxation phase. Atropine lowered LESP and abolished the initial rise in LESP induced by NGES. Conclusions: Low frequency ES of the LES increases LESP in conscious dogs. NGES has dual effect on LESP: an initial stimulation, cholinergically mediated, followed by relaxation mediated by nitric oxide.     

Awareness of HIV/AIDS among primary school pupils in north central region of Nigeria

ObjectiveTo determine the knowledge of HIV/AIDS among primary school pupils in north central area of Nigeria.Methods2000 randomly selected primary school pupils in and around eastern part of Idoma area of Benue state were interviewed using an open-ended questionnaire. Data analysis was done with EPI-INFO 2000. The Chi-square test was used for statistical analysis and the 0.05 level of significance was adopted.ResultsA totle of 1010 males and 990 females at ages between five and sixteen years were drawn from 10 primary schools in the area. Pupils in the higher classes were more knowledgeable and sex difference was not statistically significant. Certain misconceptions were noted.ConclusionsThere is need for health education for all cadres of primary school pupils in the area, which will increase the awareness of the disease.