Pilot Study for Assessment of Optimal Frequency for Changing Catheters in Insulin Pump Therapy��Trouble Starts on Day 3

Background

Continuous subcutaneous insulin infusion (CSII) by means of insulin pump devices is considered to be one of the most optimal therapies to achieve treatment targets in patients with diabetes mellitus. In CSII, the insulin is delivered through Teflon catheters or steel needle infusion sets, which need to be renewed on a regular basis. This pilot study was performed to investigate the optimal change frequency in daily practice and to explore potential problems that may occur when the sets are used for a more prolonged time than the recommended up to 72 hours of usage (Teflon catheters).

Method

Twelve patients with type 1 diabetes participated in the trial [age (mean ± STD): 40.3 ± 12.6 years, body mass index: 26.2 ± 3.3 kg/m², hemoglobin A1c: 6.7 ± 0.6%]. They were asked to wear their infusion set (Comfort™ or Silhouette^®) for increasing periods of 1, 2, 3, 4, and 5 days. After each use, patients completed standardized questionnaires regarding technical and medical issues associated with infusion set use. A health care professional investigated the infusion sites and infusion sets and completed an “infusion set inspection” questionnaire. Blood glucose was measured and recorded to assess a potential influence of duration of catheter use on glycemic control.

Results

Infusion set and injection site problems (itching, bruising, swelling, and pain) started to occur in measurable amounts on the 3rd day of catheter use, and about 40% of patients reported significant issues when using a catheter for 5 days. In parallel, there was a consistent increase in mean daily blood glucose levels that correlated with the number of days of catheter use (e.g., day 1: 7.5 ± 3.8 mmol/liter, day 3: 8.4 ± 4.2 mmol/liter, day 5: 9.0 ± 4.0 mmol/liter, day 7: 11.6 ± 2.2 mmol/liter, p < 0.05 vs day 1).

Conclusions

Using the catheters for 2 days resulted in a safe and well-tolerated therapy. Clinically relevant adverse events started to occur during the 3rd day and their incidence increased constantly with longer use. This was associated with undesired changes in mean glycemic control. Data support the recommendation by the drug and device manufacturers that insulin pump catheters should only be used for 48–72 hours to avoid adverse events and potential metabolic deterioration.     

Real Time PCR TaqMan assays for detection of polyomaviruses KIV and WUV in clinical samples

Recently, polyomaviruses KI and WU were identified in the airways of patients with acute respiratory symptoms. The epidemiology and pathogenesis of these two viruses are not fully understood, and the development of molecular assays, such as Real Time PCR, was useful for examining their biology and role in different clinical syndromes. The evaluation of different target regions for the amplification of polyomaviruses KI and WU, comparing published primer/probe sets and sets designed in the laboratory is described and was used for testing 175 clinical specimens (84 stools and 91 tonsils). The results showed that the laboratory designs were more sensitive for the detection of polyomaviruses KI and WU DNA in clinical samples. The choice of the primer/probe set, and primarily of the region for amplification, may be relevant for understanding the pathogenic role of viruses such as polyomaviruses KI and WU.     

Neural basis of stable perception of an ambiguous apparent motion stimulus

Although it has been shown that an alternative dominant percept induced by an ambiguous visual scene has neural correlates in various cortical areas, it is not known how such a dominant percept is maintained until it switches to another. We measured the primary visual response to the two-frame bistable apparent motion stimulus (stroboscopic alternative motion) when observers continuously perceived one motion and compared this with the response for another motion using magnetoencephalography. We observed a response component at around 160 ms after the frame change, the amplitude of which depended on the perceived motion. In contrast, brain responses to less ambiguous and physically unambiguous motions in both the horizontal and vertical directions did not evoke such a component. The differential response evoked by the bistable apparent motion is therefore distinct from directionally-selective visual responses. The results indicate the existence of neural activity related to establish and maintain one dominant percept, the magnitude of which is related to the ambiguity of the stimulus. This is in the line with the currently proposed idea that dominant percept is established in the distributed cortical areas including the early visual areas. Further, the existence of the neural activity induced only by the ambiguous image suggests that the competitive neural activities for the two possible percepts exist even when one dominant image is continuously perceived.     

Perspectives on optometric visual training

The enhancement of visual information acquisition and processing abilities is the essential purpose for a patient's involvement in an optometric visual training regimen. A rationale for a holistic approach is considered. The successful completion of any visual training case is dependent on appropriate optometric management and a motivated and compliant patient. Patients must develop their own visual efficiency. The optometrist can assist by arranging conditions for success. The role the optometrist plays during implementation of visual training is reviewed. The need to plan an appropriate sequence of ‘procedures’ into an individualised curriculum is emphasised.     

一类高维Cantor型集合的Hausdorff维数

本文利用有关集合直积的Hausdorff维数与Hausdorff密度关系的理论,得到了一类高维Cantor型集合的Hausdorff维数,由此可构造出具有任意给定的Hausdorff维数的集合。     

一种新型的专家系统—可拓专家系统

首次将可拓集合论和物元理论应用于专家系统的知识表达,并在此基础上建立了一套以关联度为判断准则的系统运行机制,试图提高专家系统的知识表达能力,进而提高专家系统的智能水平。     

Effect of resistance exercise volume and complexity on EMG,strength, and regional body composition

This study was designed to examine the effects of a 12-week resistance training program using single versus multiple sets of a complex versus simple exercise on EMG, strength and regional body composition. Twenty-eight untrained men (n=15) and women (n=13) performed resistance training twice per week. Group 1 (S-1, n=9) performed one set of a leg press (LP) and bicep curl (BC) exercise, group 2 (M-6, n=9) performed six sets of a LP and BC exercise, and group 3 (C, n=10) was the control group. One-repetition maximums (1RMs) and EMG were measured in the LP and BC during pre-, mid-, and post-training. Lean body mass of the legs and arms were measured pre- and post-training by dual energy X-ray absorptiometry. Results of the study indicated that both S-1 and M-6 groups significantly increased percentage strength pre- to post-training in both the LP and BC [S-1 pre-/post-LP=41.2 (23.7)%, BC=8.5 (6.71)%; M-6 pre-/post-LP=52.6 (12.6)%, BC=22.8 (15.6)%; mean (SD)]. However, compared to S-1, M-6 showed a significantly greater increase in percentage strength in the BC (P0.05) from pre- to post-testing. Results also showed that M-6 produced a significant increase in biceps (single-joint) muscle EMG values pre- to mid-testing compared to S-1. There were no significant differences found in lean muscle mass gains for the legs or arms in either training group. The data from this study suggest that multiple sets produce a greater increase in percentage strength gain for a simple exercise. It is possible that some type of neural mechanism is responsible for the observed difference.     

Spanning set defines variability in locomotive patterns

The purpose of the investigation was to use the spanning set methodology to quantify variability in locomotive patterns and to compare this method with traditional measures of variability. Subjects ran on a treadmill while sagittal plane kinematic data were collected with a high-speed (180 Hz) camera. Changes in variability were evaluated as the subject ran barefoot and in shoes. Mean ensemble curves for the knee angle during the stance period were created for each condition. From these curves, traditional measures of variability were calculated using the coefficients of variation (CVs), and the mean deviation (MD). Spanning set vectors were defined from the coefficients of polynomials that were fitted to the respective standard deviation curves. The magnitude of the spanning set was determined by calculating the norm of the difference between the two vectors. The normalised difference between the two conditions was 6.6%, 6.9% and 98%, for the MD, CV and spanning sets, respectively. The results indicated that the spanning set was capable of statistically (p<0.05) determining differences in variability between the two conditions. CV and MD measures were unable to detect statistical differences (p>0.05) between the two conditions. The spanning set provides an alternative, and sensitive measure for evaluating differences in variability from the mean ensemble curve.     

Topical cardiac cooling--computer simulation of myocardial temperature changes

Topical cardiac cooling (TC) is often used in cardiac surgery. We used a computer simulation to study temperature changes in the heart, especially in the right ventricular wall. A three-dimensional computer heart model, derived from Visible Human Data set, National Library of Medicine was used. The model is made from cubes, with spatial resolution of 1mm. Explicit Finite Different method and temperature diffusion equation were used to calculate new temperatures. Three different simulations were performed and simulated temperatures were drawn on a cross-section of heart model in different colors. The results show that areas not immersed into TC solution are less protected against ischemia. It is important not to rely solely on topical cooling but use appropriate method of myocardial protection technique.     

人操作者的模糊控制模型

在人-机-环境系统中,作为工作主体的人操作者,主要完成控制和决策两种功能。根据人的信息输入/输出关系,建立人的数学模型,是人-机-环境系统工程研究的最关键步骤。本文首先阐述了人控制模型的发展概况,接着对人操作者的模糊控制模型进行了数学描述,并给出了人控制飞船时的模型举例,最后还对模型的应用前景进行了展望。