Development and validation of a risk-score model for subjects with impaired glucose tolerance for the assessment of the risk of type 2 diabetes mellitus-The STOP-NIDDM risk-score

AIMS

To develop a risk-score model, based on available clinical data to assess absolute risk of type 2 diabetes among people with impaired glucose tolerance (IGT).

METHODS

Data from the study to prevent non-insulin dependent diabetes mellitus (STOP-NIDDM) investigating acarbose treatment in individuals with IGT were used to develop multivariable Cox proportional hazards model for the time to onset of diabetes. The final model equation was externally validated using data from the Finnish Cardiovascular Risk Factor (FINRISK) population.

RESULTS

The risk-score model included the variables acarbose treatment, gender, serum triglyceride level, waist circumference, fasting plasma glucose, height, history of cardiovascular disease (CVD) and hypertension. The final model yielded an area under the receiver-operating-characteristic curve (AUC(ROC)) of 0.64 when applied to people with IGT in the STOP-NIDDM, and 0.84 and 0.90 when applied to FINRISK population with IGT alone and IGT and normal glucose tolerance combined, respectively; AUC(ROC) is a measure of the discriminatory power of the model (1, perfect discrimination).

CONCLUSIONS

The STOP-NIDDM risk-score is a simple and validated tool that can identify high-risk individuals with IGT who would benefit most from type 2 diabetes or CVD prevention strategies, such as lifestyle management or early acarbose treatment.

The Gabor superlens as an alternative wafer-level camera approach inspired by superposition compound eyes of nocturnal insects

We present the microoptical adaption of the natural superposition compound eye, which is termed "Gabor superlens". Enabled by state-of-the-art microoptics technology, this well known principle has been adapted for ultra-compact imaging systems for the first time. By numerical ray tracing optimization, and by adding diaphragm layers and a field lens array, the optical performance of the Gabor superlens is potentially comparable to miniaturized conventional lens modules, such as currently integrated in mobile phones. However, in contrast to those, the Gabor superlens is fabricated using a standard microlens array technology with low sag heights and small diameter microlenses. Hence, there is no need for complex diamond turning for the generation of the master structures. This results in a simple and well controllable lens manufacturing process with the potential to high yield.

Artificial neural superposition eye

We propose an ultra-thin imaging system which is based on the neural superposition compound eye of insects. Multiple light sensitive pixels in the footprint of each lenslet of this multi-channel configuration enable the parallel imaging of the individual object points. Together with the digital superposition of related signals this multiple sampling enables advanced functionalities for artificial compound eyes. Using this technique, color imaging and a circumvention for the trade-off between resolution and sensitivity of ultra-compact camera devices have been demonstrated in this article. The optical design and layout of such a system is discussed in detail. Experimental results are shown which indicate the attractiveness of microoptical artificial compound eyes for applications in the field of machine vision, surveillance or automotive imaging.

Analytic modeling of the angular sensitivity function and modulation transfer function of ultrathin multichannel imaging systems

We propose what we believe to be a novel, refined model of the angular sensitivity function of artificial apposition compound eyes. Compared with the formerly used Gaussian approximation that was derived for natural compound eyes, our model is better suited to describe the resolution capacity of artificial compound eyes accounting for the cylindrical sensitivity function of technical receptors. It is shown that this analytic model is valid over a broad range of parameters of the optical system, which was not fulfilled by one of the previous models. Finally, an analytic approach is used to derive the modulation transfer function of these multichannel imaging systems.

Artificial compound eye applying hyperacuity

Inspired by the natural phenomenon of hyperacuity, redundant sampling in combination with the knowledge about the impulse response of the imaging system is used to extract highly accurate information using a low resolving artificial apposition compound eye. Thus the implementation of a precise position detection for simple objects like point sources and edges is described.

Active sites for NO reduction over Fe-ZSM-5 catalysts

A study of Fe-ZSM-5 catalysts with variable amounts of isolated, oligomeric and heavily aggregated Fe3+ oxo sites (as evidenced by UV-Vis and EPR spectroscopic data) and their catalytic properties in the selective catalytic reduction of NO by isobutane or by NH3 is presented, which allows development of a unified concept of the active Fe sites in these reactions, according to which isolated Fe sites catalyse both SCR reactions while oligomeric sites, though also involved in the selective reduction path, limit the catalyst performance by causing the total oxidation of the reductant.

Safety and Tolerability of Acarbose in the Treatment of Type 1 and Type 2 Diabetes Mellitus

OBJECTIVE

To assess the safety profile of acarbose treatment over a 1-year period at a dose range of 50-300mg three times daily in patients with type 1 or type 2 diabetes mellitus.

STUDY DESIGN AND PATIENTS

In this 56-week, double-blind, parallel-group, multicentre comparison, patients were randomised to acarbose or placebo in a 2 : 1 ratio. An 8-week forced titration phase (from 50-300mg three times daily) was followed by a 48-week maintenance phase during which patients received the highest dose tolerated during titration. Patients were assessed at 13 visits with respect to adverse events/intercurrent illnesses, abnormal laboratory values (serum chemistry, urinalysis, complete blood and reticulocyte count, serum iron and total iron binding capacity, and serum vitamin B(6), B(12), D and folate levels), discontinuation rates, ECG findings, vital signs and evaluation of the patients' diaries with regard to gastrointestinal events. A total of 359 patients (acarbose 240, placebo 119) were valid for analysis; 21% had type 1 diabetes. Most patients received concomitant insulin or sulfonylurea treatment.

RESULTS

Study withdrawal was reported for 35% of acarbose and 24% of placebo recipients (p = 0.053); adverse events were the main reason for withdrawal in acarbose recipients (20%; placebo group 5%; p < 0.01). The most common adverse events for acarbose recipients were gastrointestinal (abdominal pain, flatulence and diarrhoea), which were more frequent than in placebo patients (p < 0.01). These events occurred more often early in the study and attenuated over time.

CONCLUSION

Acarbose was safe and well tolerated by the majority of diabetic patients over a 1-year treatment period.

Long-Term Efficacy and Tolerability of Acarbose Treatment in Patients with Type 2 Diabetes Mellitus

OBJECTIVE

The aim of the study was to investigate the efficacy and tolerability of long-term acarbose therapy in type 2 diabetic patients.

STUDY DESIGN

In this double-blind, single-centre group comparison, patients were randomised to receive either acarbose or matching placebo, in addition to their regular antidiabetic therapy, over a period of 78 weeks. Eligibility for inclusion in the efficacy evaluation included a study duration of >/=510 days.

METHODS

The primary efficacy parameter was the change in glycosylated haemoglobin (HbA(1)) from baseline to end of study. Secondary variables included changes in blood glucose and lipid parameters, as well as signs of retinopathy and nephropathy.

PATIENTS

A total of 139 patients were assessed for safety and 88 patients (44 in each treatment group) were included in the efficacy analysis. Patients were generally overweight and the majority had previously been treated with sulphonylureas.

RESULTS

Acarbose significantly improved fasting and 1-hour postprandial blood glucose levels compared with placebo (p = 0.039 and 0.009), and improvements in HbA(1) with acarbose versus placebo fell just short of significance (p = 0.057). There were no differences between treatments in changes in microvascular complications, but blood pressure improved with acarbose treatment. Two patients in the acarbose group experienced elevated liver enzyme levels. Generally, acarbose had a good safety profile and was well tolerated.

CONCLUSION

Long-term treatment with acarbose was safe and efficacious in patients with type 2 diabetes mellitus that was insufficiently controlled by other oral antidiabetics.

Primary stability of a robodoc implanted anatomical stem versus manual implantation

OBJECTIVE

To assess the initial stability of anatomical stems implanted in manually broached femoral cavities compared with that assessed in cavities milled with the robodoc system.

DESIGN

The bone-prosthesis interface motion was measured in matched pairs of cadaveric femora to assess the initial stability of anatomical stems implanted with two different implantation techniques.

BACKGROUND

The high costs of surgical robots and the increased perioperative efforts associated with their use can only be justified if measurable benefits for patients can be achieved. Increased initial stability of the stem as an early indicator for better bone ongrowth would be such a benefit.

METHODS

Seven pairs of fresh frozen human cadaveric femora were used. One femur of each pair was randomly assigned to receive the robotic milling method; the other femur underwent manual broaching by an experienced surgeon. Initial micromotions of the anatomical stems were measured during simulated gait cycles with loads of < or =1500 N, and both groups underwent matched-pair analysis. Results. High motion of the prostheses was found for both implantation techniques.

CONCLUSIONS

The robodoc system did not enhance the primary stability of the anatomical prosthesis compared with the manual broaching method.