Abdominal Aortic Aneurysm Screening Using Non-imaging Hand-held Ultrasound Volume Scanner – A Pilot Study

BACKGROUND: Screening for abdominal aortic aneurysms (AAA) is cost-effective and timely repair improves outcome. Using standard ultrasound (US) an AAA can be accurately diagnosed or ruled-out. However, this requires training and bulk equipment. AIM: To evaluate the diagnostic potential of a new hand-held ultrasound bladder volume indicator (BVI) in the setting of AAA screening. METHODS: In total, 94 patients (66 +/- 14 years, 67 men) referred for atherosclerotic disease were screened for the presence of AAA (diameter > 30 mm using US). All patients underwent both examinations, with US and BVI. Using the BVI, aortic volume was measured at 6 pre-defined points. Maximal diameters (US) and volumes (BVI) were used for analyses. RESULTS: In 54 (57%) patients an AAA was diagnosed using US. The aortic diameter by US correlated closely with aortic volume by BVI (r = 0.87, p < 0.0001). Using a cut-off value of > or = 50 ml for the presence of AAA by BVI, sensitivity, specificity, positive and negative predictive value of BVI in detection of AAA were 94%, 82%, 88% and 92%, respectively. The agreement between the two methods was 89%, kappa 0.78. CONCLUSION: The bladder volume indicator is a promising tool in screening patients for AAA.     

炎宁冲剂的抗炎与解热作用研究

目的：研究炎宁冲剂的抗炎与解热作用。方法：采用角叉菜胶致大鼠足跖炎性肿胀。二甲苯致小鼠耳毛细血管通透性增高,以及大鼠皮下羧甲基纤维素囊中白细胞出游等急性炎症模型研究炎宁冲剂的抗炎作用。采用啤酒酵母液引起家兔发热的方法研究炎宁冲剂的解热作用。结果：炎宁冲剂对以上实验动物均具有明显的抗炎和解热作用。结论：炎宁冲剂对急性炎症具有明显的抗炎作用。对啤酒酵母液引起家兔发热具有明显解热作用。     

青年人群腰椎骨密度及标准差对骨质疏松检出率的影响：多中心、大样本分析

背景: 不同地区骨峰值和标准差不同，对骨质疏松诊断率有较大影响。探讨建立一完整数据库为中国人骨质疏松诊断准确性提供依据。 目的：探讨青年人腰椎骨密度和标准差正常参考值影响骨质疏松症检出率的程度。 设计、时间及地点：调查分析，于1997-01/1999-12分别在北京、上海、广州、南京、嘉兴和成都市完成。 对象：采用前瞻性及回顾性方法对全国6个中心骨密度参考数据库中11 418人进行调查统计分析；男3 666人，女7 752人；年龄20岁~90岁；分别来自北京(2 385人)、广州(1 178人)、上海(1 404人)、南京(2 938人)、成都(1 425人)、嘉兴(2 088人),受试者来源于社区调查、健康体检和健康志愿者。 方法：用GE-Lunar公司的DXA仪测量骨密度，调查全国6个中心11 418人L2~L4腰椎后前位和髋部骨密度，建立了骨密度参考数据库。6个中心的仪器内部精度0.3%~0.7%，仪器间的精度1.1%。 主要观察指标：①6个中心不同年龄组腰椎骨密度分布。②青年人群骨密度及其标准差值对骨质疏松症检出率的影响。 结果：中国汉族女性以腰椎进行骨质疏松症诊断的青年人群的骨密度和标准差值，6个中心，最大差值分别为0.098 g/cm2和0.027 g/cm2。用6个中心及总体各自的青年人平均骨密度和标准差值为参考标准，对同一人群计算T-score和获得的骨质疏松症检出率不相同；发现青年人平均骨密度每变化0.01 g/cm2，则骨质疏松症检出率变化1.6%(呈正相关)，其标准差值每变化 0.01 g/cm2，则骨质疏松症检出率变化4%(呈负相关)。 结论：青年人平均骨密度和标准差值不同引起骨质疏松症检出率也不相同。为了让不同中心的骨质疏松症检出率有可比性,建议同一个类型的骨密度仪,同一个种族,同一个地区用一个设计较完善大样本的参考数据库,以其青年人正常参考值计算T-score。     

Spatial and Temporal Effects of Interleaved Masking in Cochlear Implants

Modern cochlear implants utilize interleaved presentation of pulses on different electrodes to avoid physical interference among multiple current fields, yet neural interaction still exists. In the present study, masking was examined with four Nucleus24 users with the banded electrode array in an interleaved masking paradigm, where a probe stimulus was interleaved with a masker stimulus. Spatial and temporal aspects of masking were addressed by fixing the masker at the middle of the electrode array and changing the location of the probe and by testing various stimulation rates: 125, 500, 2,000, and 6,410 Hz. In addition, growth of masking (GOM) was assessed by changing the masker level in six steps. Results indicated that masking patterns were generally much wider, regardless of stimulation rate, than those in acoustic hearing. The amount of masking decreased from the peak at the rate of approximately 0.5 dB/mm even at the highest masker level. The pattern of GOM with the rates higher than 500 Hz was different from that observed in previous masking studies, characterized by markedly shallow growth at low masker levels or overall shallow growth. A facilitating effect of the masker (lowering the threshold) was suspected, except for the 125-Hz condition, due to the fibers that were subliminally excited, but not discharged, by the masker with local perturbations of membrane potentials, and were subsequently discharged easily by a lower level probe when the temporal gap between masker and probe was sufficiently short. These results suggest that both refractory characteristics of neurons and neural summation be considered in interleaved stimulation of pulses at high, but clinically relevant, stimulation rates. Overall, the present masking study might provide a basis for models in psychophysics and speech understanding in current cochlear implant systems utilizing high-rate interleaved stimulation.     

Multilayer Transducer for Acoustic Bladder Volume Assessment on the Basis of Nonlinear Wave Propagation

Catheterization remains the gold standard for bladder volume assessment, but it is invasive, uncomfortable to the patient and introduces the risk of infections and traumas. Acoustic measurement of the bladder volume reduces the need for a urinary catheter. Recently, a new method to non-invasively measure the volume of liquid filled cavities in vivo on the basis of nonlinear wave propagation has been introduced. To implement this method, two different multilayer ultrasound transducers were developed. Both transducers consisted of a first piezo-electric layer of lead zirconate titanate (PZT) to transmit waves at a fundamental frequency (2 MHz) and a second piezo-electric layer (copolymer) to receive a wide range of frequencies including harmonics. To suppress the inherent susceptibility of the film to electromagnetic waves, one of the two transducers, i.e., an “inverted” multilayer transducer, had the copolymer layer located inside the structure. The other multilayer transducer, i.e., a “normal” multilayer transducer, had the copolymer film located on the outside. Both transducers were compared with a commercially available broadband piezo-composite transducer, with respect to their transmit and receive transfer functions, their pulse-echo responses and their electromagnetic susceptibility (EMS) in reception. It was concluded that to measure up to at least the third harmonic frequency component with good sensitivity in combination with high transmit sensitivity at the fundamental frequency, a multilayer structure is preferred. To optimize for the EMS in reception, and hence also the signal-to-noise ratio, an inverted geometry, as proposed in this paper, was proven to be most effective. (E-mail: e.merks@erasmusmc.nl)     

Lack of association between ACE and bradykinin B2 receptor gene polymorphisms and ACE inhibitor-induced coughing in hypertensive Koreans

Background & Objective:  Angiotensin converting enzyme (ACE) inhibitors are used widely in therapy for hypertension, congestive heart failure and myocardial infarction. However, coughing, one of their major adverse effects limits their use. It is documented that Asians are more liable to coughing than Europeans. The aim of this study was to investigate genetic polymorphism involved in ACE inhibitor-induced coughing.
Methods:  We monitored hypertensive subjects ( n  = 110) treated with ACE inhibitors, and tested for any associations between ACE inhibitor-induced coughing and polymorphisms in the genes for ACE and the bradykinin B2 receptor, which are suspected to be related to coughing.
Results & Discussion:  We found no significant differences between the groups with coughing and without coughing in the frequency of ACE I/D (Insertion/Deletion) polymorphisms. One single nucleotide polymorphism was discovered in the promoter (−58T/C) and, one in intron-exon junction upsteam of exon 2 (−59C/A), of the bradykinin B2 receptor gene. However, no significant correlation was found between those genotypes or allele distributions and ACE inhibitor-induced coughing.
Conclusion:  We found no significant links between polymorphisms of the ACE gene or bradykinin B2 receptor gene with ACE inhibitor-induced coughing in hypertensive Koreans. But, the topic remains controversial and requires more study.     

Activation products of the haemostatic system in coronary, cerebrovascular and peripheral arterial disease

To determine the presence of a 'hypercoagulable state' as assessed by indices of thrombin and plasmin generation and of the amount of fibrin that is lysed, in patients with stable coronary, cerebral and peripheral arterial disease a population-based cross-sectional study was performed. From a population-based cohort comprising 7983 men and women aged 55 years and over, we randomly selected 127 subjects with a history of myocardial infarction, 124 with a history of stroke and/or transient ischemic attack, 131 patients with peripheral arterial disease and 263 control subjects in the same age group without arterial disease. Subjects using anticoagulant drugs were not selected. F1+2, TAT, and PAP were not associated with a history of cardiovascular events, nor with peripheral arterial disease. In contrast, positive associations were found for D-Dimer. Mean D-Dimer level was 40 microg/l (95% CI 35, 44) in control subjects; 53 microg/l (47, 61) in those with a history of myocardial infarction and 51 microg/l (45, 58) in those with a history of stroke and or transient ischemic attack. D-Dimer increased gradually with increasing severity of peripheral atherosclerosis; a decrease in ankle/arm systolic blood pressure ratio of 0.1 was associated with an increase in D-Dimer of 3.9 microg/l (p<0.01). This was more pronounced in subjects with higher F1+2, TAT and PAP concentration. In conclusion, the markers of onset of coagulation F1+2, TAT and PAP are not associated with the presence of arterial disease, but increased levels of these markers are necessary for the positive association between D-Dimer and arterial disease.