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71.
Stenosis phantoms were created to study the ability of "black blood" methods to image a vessel stenosis in the presence of pulsatile flow. Black blood images were acquired with a modified TurboFLASH (fast low-angle shot) method that eliminates flow signal by applying a set of prepulses before segmented data acquisition. With this high-speed approach, imaging can be completed within 16 seconds. This technique was compared with conventional spin-echo black blood, gradient-echo black blood, and gradient-echo bright blood methods. Loss of flow signal, which extended beyond the site of the stenosis, was seen on the gradient-echo bright blood images. The pattern of signal loss varied with the type of stenosis. Flow voids were achieved with spin-echo black blood imaging; however, substantial ghosting artifacts were seen. With gradient-echo black blood imaging, it was difficult to eliminate all flow signal, particularly for in-plane flow. The modified TurboFLASH method produced high-quality black blood images in a fraction of the time needed for spin-echo imaging. It showed no ghosting artifacts even in the presence of pulsatile flow.  相似文献   
72.
Maj M 《Bipolar disorders》2000,2(2):93-101
A critical review is provided of the available research evidence concerning the efficacy and effectiveness of lithium prophylaxis in bipolar disorder. It is emphasized that, in spite of the limitations of available placebo-controlled trials and naturalistic studies, lithium is the only drug whose prophylactic activity in bipolar disorder is convincingly proved, and remains the first-choice medication in the long-term treatment of bipolar patients. The impact of lithium prophylaxis is likely to be less significant on atypical and comorbid cases of bipolar disorder than in typical manic–depressive illness, but the superiority of other medications over lithium in the long-term treatment of those cases is at present not convincingly proved by research. Currently available research evidence does not seem to support the idea that lithium exerts its prophylactic effect on relapses but not on recurrences of bipolar disorder. Clinicians should be aware of the fact that the drop-out rate in bipolar patients receiving long-term lithium prophylaxis is high even if treatment surveillance is accurate, and that complete suppression of recurrences is a relatively rare outcome of prophylaxis.  相似文献   
73.
目的探讨30年来我院子的变化特点. 方法回顾性分析1971~2000年期间发生的98例子病例. 结果子的发生率由70年代0.3%降至90年代0.1%(P<0.01),产前子占子总数的比率由70年代52.1%降至90年代26.3%(P<0.05),产后子由70年代20.8% 升至90年代47.4%(P<0.05).围产儿死亡率由70年代203.7‰下降至90年代100.0‰. 三个年代子所致孕产妇的死亡占同期子的比率依次为4.2%、6.5%、5.3%(P>0.05 ). 结论 30年来子的发生率明显下降,子类型构成比发生明显变化 ,产前子减少,产后子相对增多,子患者的围产儿死亡率逐渐下降,子致孕产妇死亡率未降低.  相似文献   
74.
BACKGROUND: Tobacco smoking is one of the main risk factors for oral, pharyngeal and oesophageal cancers in developed countries. Information on the role of the tar yield of cigarettes in upper digestive tract carcinogenesis is sparse and needs to be updated because the tar yield of cigarettes has steadily decreased over the last few decades. PATIENTS AND METHODS: We analysed two case-control studies, from Italy and Switzerland, conducted between 1992 and 1999, involving 749 cases of oral and pharyngeal cancer and 1770 controls, and 395 cases of squamous-cell oesophageal carcinoma and 1066 matched controls. Odds ratios (ORs) were estimated by unconditional multiple logistic regression models, including terms for age, sex, study centre, education and alcohol consumption. RESULTS: Based on the brand of cigarettes smoked for the longest time, the multivariate ORs for current smokers compared with never smokers were 6.1 for <20 mg and 9.8 for >or=20 mg tar for oral and pharyngeal neoplasms, and 4.8 and 5.4 for oesophageal cancer, respectively. For the cigarette brand smoked in the previous six months, the ORs for >or=10 mg compared with <10 mg were 1.9 for cancer of the oral cavity and pharynx and 1.8 for oesophageal cancer, after allowance for number of cigarettes and duration of smoking. CONCLUSIONS: The present study confirms the direct relationship between the tar yield of cigarettes and upper digestive tract neoplasms, and provides innovative information on lower tar cigarettes, which imply reduced risks compared with higher tar ones. However, significant excess risks were observed even in the lower tar category, thus giving unequivocal indications for stopping smoking as a priority for prevention of upper digestive tract neoplasms.  相似文献   
75.
T-lymphocyte cell function was studied in vitro in peripheral blood mononuclear cells (PBMC) from 61 male patients with head and neck squamous cell carcinomas compared to 46 control patients. Patients older than 80 years or with reduced tumor-related performance status as measured by Karnofsky score less than 75 were excluded. In contrast to previous similar studies, control subjects ensured a minimum stress load by sampling all patients on the day of either diagnostic or therapeutic surgery. PBMC were separated by density-gradient centrifugation and subsequently cultured with autologous sera in vitro. The mitogen concanavalin A (Con A), which stimulates all T-cell clones, was employed. Findings showed that increased Con A stimulation and PBMC proliferation occurred with PBMC from cancer patients compared to that from control patients. In contrast, no differences could be detected with respect to the stimulated supernatant level of interleukin-2, interleukin-4 or interferon-γ between the groups. These results suggest that T-lymphocytes from PBMC are generally affected by neoplastic disease through either a supporting cell or serum factor.  相似文献   
76.
对41例儿童旋毛虫病的临床观察   总被引:5,自引:0,他引:5  
为了解儿童旋毛虫病的临床特征,对1992~1995年就诊的41例儿童旋毛虫病进行分析。结果表明,患儿来自河南6个地区,主要因食猪肉馅饺子、烤羊肉串或食涮猪肉而感染。冬季为本病的高发季节。患儿平均年龄为8.8岁,男女之比为2.71。长期发热和嗜酸性粒细胞增多为本病的主要表现,仅少数患儿有肌痛、胃肠道症状和皮疹。眼睑水肿仅见于发病早期。血清学检查对诊断本病有重要意义。预防本病的关键措施是加强肉检和改变不良的饮食习惯。  相似文献   
77.
目的:比较徒手和卵圆钳两种方法对产后立即放置(IPPI)宫内节育器(IUD)效果的影响。方法:将910例阴道分娩产妇(其中97.7%是首次分娩)随机分成两组,于胎盘娩出后10分钟内放置TCu380AIUD,其中470例徒手放置(手放组),440例用卵圆钳放置(钳放组)。随访12个月,以生命表法统计、χ2检验比较两种放置方法的脱落率、妊娠率、因症取出率等。结果:6和12个月的随访率分别为95.16%和92.64%。910例中未发生子宫穿孔和感染,仅手放组有1例带器妊娠。放置后主要停用原因是脱落,手放组与钳放组12个月的粗累积脱落率分别为15.86/100妇女和15.88/100妇女,因症(出血、疼痛)取出率分别为2.11/100妇女和1.57/100妇女,差异无显著性(P均>0.05)。结论:徒手放置或卵圆钳放置对IPPI的效果无明显影响;TCu380AIUD适合中国妇女产后立即放置。  相似文献   
78.
The objective of this study was to examine the effects of the intakeof dietary fat upon colorectal cancer risk in a combined analysis of datafrom 13 case-control studies previously conducted in populations withdiffering colorectal cancer rates and dietary practices. Original datarecords for 5,287 cases of colorectal cancer and 10,470 controls werecombined. Logistic regression analysis was used to estimate odds ratios (OR)for intakes of total energy, total fat and its components, and cholesterol.Positive associations with energy intake were observed for 11 of the 13studies. However, there was little, if any, evidence of anyenergy-independent effect of either total fat with ORs of 1.00, 0.95, 1.01,1.02, and 0.92 for quintiles of residuals of total fat intake (P trend =0.67) or for saturated fat with ORs of 1.00, 1.08, 1.06, 1.21, and 1.06 (Ptrend = 0.39). The analysis suggests that, among these case-control studies,there is no energy-independent association between dietary fat intake andrisk of colorectal cancer. It also suggests that simple substitution of fatby other sources of calories is unlikely to reduce meaningfully the risk ofcolorectal cancer.  相似文献   
79.
A longitudinal growth study with monthly measurements during the 1st year of life was conducted by nine paediatricians working in private practice in Zurich. Of 92 children, none was lost to the study and only 32 of 1104 planned visits were missed; the quality of the measurements was comparable to that of a specialised university clinic. Compared to the Zurich Longitudinal Growth Studies, children of this study were considerably heavier and taller. In 92% of the subjects, growth velocity was at least once outside the reference range (3rd–97th percentile). For weight increments, the corresponding proportion was 87%. Conclusions The data indicate that current standards for the 1st year of life for the Zurich area might no longer be appropriate and need to be updated. The currently used velocity percentiles based on 3-monthly measurements are not suitable to assess individual height and weight increments calculated from monthly measurements. Received: 9 June 1997 / Accepted in revised form: 21 November 1997  相似文献   
80.
The aim of this study was to investigate the usefulness of contrast-enhanced harmonic power Doppler ultrasound (US) for the detection of residual viable hepatocellular carcinoma (HCC) after treatment with transcatheter arterial chemoembolization (TACE). Forty-seven patients with 68 HCC lesions 1.8–9.5 cm in diameter (mean ± SD 4.3 ± 1.7 cm) underwent contrast-enhanced power Doppler US, in the harmonic mode, before and after treatment with TACE. Unenhanced spiral CT and contrast-enhanced dynamic MR imaging were also performed to help establish the outcome of therapy. Before treatment, intratumoral blood flow signals were detected at contrast-enhanced harmonic power Doppler US in 65 (95 %) of 68 lesions. After TACE, flow signals were no longer detectable in 22 of these 65 lesions, which showed complete response at spiral CT and dynamic MR imaging. In 38 (88 %) of the 43 lesions with partial response, intratumoral flow signals were still identified at contrast-enhanced harmonic power Doppler US. Twenty-eight of these 38 lesions underwent additional treatment with percutaneous ethanol injection (PEI) using contrast-enhanced harmonic power Doppler US guidance. Complete response was seen after PEI in 23 of 28 lesions. Contrast-enhanced harmonic power Doppler US proved useful for assessing the therapeutic effect of TACE on HCC and for guiding additional treatment with PEI in cases of partial response. Received: 25 January 2000; Revised: 21 April 2000; Accepted: 25 April 2000  相似文献   
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