Outbreak of Salmonella enterica Goldcoast infection associated with whelk consumption, England, June to October 2013

An increase in the number of cases of Salmonella enterica serotype Goldcoast infection was observed in England during September 2013. A total of 38 cases were reported, with symptom onset dates between 21 June and 6 October 2013. Epidemiological, environmental, microbiological and food chain evidence all support the conclusion that this outbreak was associated with eating whelks processed by the same factory. Whelks are a novel vehicle of Salmonella infection and should be considered when investigating future outbreaks.

[Assessment of mesopic and contrast vision for driving licences: which cut-off values, which methods are appropriate?]

BACKGROUND

Hitherto recommendations and thresholds for contrast tests are available for mesopic but not for photopic methods. While mesopic tests are widespread in ophthalmology, in occupational medicine photopic contrast tests are often used. With regard to the attachment 6 of the German Fahrerlaubnisverordnung (FeV) which is relevant since July 2011 we tested the specificity and sensitivity as well as the test-retest reliability of available test devices and defined cut-off values.

METHODS

We examined patients with medium opacities, healthy volunteers and a sample of employees. Optovist EU, Binoptometer 4P and Pelli-Robson charts with standardised illumination were applied for contrast sensitivity testing. All these methods were compared to the Mesotest II as gold standard. We followed the recommendations of the German Qualitätssicherungs-Kommission der Deutschen Ophthalmologischen Gesellschaft (DOG) for contrast vision testing and definition of cut-off values.

RESULTS

64 patients with cataract (age 42-70 years, median 62 years), 50 pilots (age 40-69 years, median 53.5 years) and 109 employees of a transportation company (age 40-59 years, median 50 years) were included in the trial. All contrast sensitivity tests showed a good sensitivity and specificity (AUC 0.86 to 0.99). For Optovist EU and Binoptometer 4P a threshold of 15 % Weber contrast is recommended for examinations according to FeV. The test-retest reliability was high in all methods with highly significant Pearson correlation coefficients of 0.77 to 0.94 and a repeatability coefficient between 0.08 und 0.4. The standard distance of 1 m common for the Pelli-Robson chart cannot be recommended for FeV examinations, while the results at 3 m distance are comparable to those of the other contrast vision tests. The preliminary cut-off for the Pelli-Robson chart at 3 m distance is 1.65.

CONCLUSIONS

Cut-off values for the lawful assessment of applicants are now available. Both Binoptometer 4P and Optovist EU proved to be appropriate and - as expected due to comparable technical properties - the same cut-off can be recommended. At 1 m distance the Pelli-Robson chart is not sensitive enough. Because the new distance of 3 m for the Pelli-Robson chart was investigated in 55 cataract patients and 10 pilots in this trial, a confirmatory trial for this distance is planned.

Intra-thoracic fat volume is associated with myocardial infarction in patients with metabolic syndrome

BACKGROUND

Visceral adiposity is increased in those with Metabolic Syndrome (MetS) and atherosclerotic disease burden. In this study we evaluate for associations between intra-thoracic fat volume (ITFV) and myocardial infarction (MI) in patients with MetS.

METHODS

Ninety-four patients with MetS, MI or both were identified from a cardiovascular CMR clinical registry. MetS was defined in accordance to published guidelines; where-as MI was defined as the presence of subendocardial-based injury on late gadolinium enhancement imaging in a coronary vascular distribution. A healthy control group was also obtained from the same registry. Patients were selected into the following groups: MetS+/MI- (N = 32), MetS-/MI + (N = 30), MetS+/MI + (N = 32), MetS-/MI- (N = 16). ITFV quantification was performed using signal threshold analysis of sequential sagittal CMR datasets (HASTE) and indexed to body mass index.

RESULTS

The mean age of the population was 59.8 ± 12.5 years. MetS+ patients (N=64) demonstrated a significantly higher indexed ITFV compared to MetS- patients (p = 0.05). Patients in respective MetS-/MI-, MetS+/MI-, MetS-/MI+, and MetS+/MI + study groups demonstrated a progressive elevation in the indexed ITFV (22.3 ± 10.6, 28.6 ± 12.6, 30.6 ± 12.3, and 35.2 ± 1.4 ml/kg/m(2), (p = 0.002)). Among MetS+ patients those with MI showed a significantly higher indexed ITFV compared to those without MI (p = 0.02).

CONCLUSIONS

ITFV is elevated in patients with MetS and incrementally elevated among those with evidence of prior ischemic myocardial injury. Accordingly, the quantification of ITFV may be a valuable marker of myocardial infarction risk among patients with MetS and warrants further investigation.

Predicting target vessel location on robot-assisted coronary artery bypass graft using CT to ultrasound registration

PURPOSE

Although robot-assisted coronary artery bypass grafting (RA-CABG) has gained more acceptance worldwide, its success still depends on the surgeon's experience and expertise, and the conversion rate to full sternotomy is in the order of 15%-25%. One of the reasons for conversion is poor pre-operative planning, which is based solely on pre-operative computed tomography (CT) images. In this paper, the authors propose a technique to estimate the global peri-operative displacement of the heart and to predict the intra-operative target vessel location, validated via both an in vitro and a clinical study.

METHODS

As the peri-operative heart migration during RA-CABG has never been reported in the literatures, a simple in vitro validation study was conducted using a heart phantom. To mimic the clinical workflow, a pre-operative CT as well as peri-operative ultrasound images at three different stages in the procedure (Stage(0)-following intubation; Stage(1)-following lung deflation; and Stage(2)-following thoracic insufflation) were acquired during the experiment. Following image acquisition, a rigid-body registration using iterative closest point algorithm with the robust estimator was employed to map the pre-operative stage to each of the peri-operative ones, to estimate the heart migration and predict the peri-operative target vessel location. Moreover, a clinical validation of this technique was conducted using offline patient data, where a Monte Carlo simulation was used to overcome the limitations arising due to the invisibility of the target vessel in the peri-operative ultrasound images.

RESULTS

For the in vitro study, the computed target registration error (TRE) at Stage(0), Stage(1), and Stage(2) was 2.1, 3.3, and 2.6 mm, respectively. According to the offline clinical validation study, the maximum TRE at the left anterior descending (LAD) coronary artery was 4.1 mm at Stage(0), 5.1 mm at Stage(1), and 3.4 mm at Stage(2).

CONCLUSIONS

The authors proposed a method to measure and validate peri-operative shifts of the heart during RA-CABG. In vitro and clinical validation studies were conducted and yielded a TRE in the order of 5 mm for all cases. As the desired clinical accuracy imposed by this procedure is on the order of one intercostal space (10-15 mm), our technique suits the clinical requirements. The authors therefore believe this technique has the potential to improve the pre-operative planning by updating peri-operative migration patterns of the heart and, consequently, will lead to reduced conversion to conventional open thoracic procedures.

Risk factors for secondary hyperparathyroidism after bariatric surgery: a comparison of 4 different operations and of vitamin D-receptor-polymorphism

OBJECTIVE

To determine the relative frequency of secondary hyperparathyroidism after 1 of 4 standard bariatric surgical procedures, with respect to vitamin D-receptor (VDR) Bsm1 genotype-polymorphism (VDRP).

METHODS

Included were 141 obese men and women [aged 44.6±10.4 years, body mass index (BMI) 44.4±5.4 kg/m²], who had undergone either gastric banding (GB; n = 39), laparoscopic sleeve-gastrectomy (LSG; n = 31), Roux-en-Y-gastric-bypass (RYGB; n=43), or biliopancreatic-diversion with "duodenal switch" (BP-DS; n = 28)]. They were tested for VDR-genotype (Bsm1), vitamin D, and serum-PTH-levels postoperatively.

RESULTS

Analysis of Covariance revealed a treatment effect, showing statistically significantly higher PTH-levels after BP-DS than after GB (mean difference = 32.14, p<0.001), after SG (mean difference = 25.18, p=0.001), or after RYGB (mean difference = 18.15, p=0.020). VDR-BSM1-genotype did not influence PTH-levels and vitamin-D postoperatively. Logistic regression indicated that the risk of developing SHPT after BP-DS was 12.5 times higher than after GB and 16.7 times higher than after SG. Beside other variables, VDR-genotype and the interaction between VDR-genotype and type of surgery did not attain statistical significance.

CONCLUSIONS

In a comparison of the 4 most frequently performed bariatric operations vitamin-D-receptor polymorphism (VDRP) had no influence on the development of postoperative secondary hyperparathyroidism (SHPT) and is not useful as a predictor. SHPT occurs most often after BP-DS. Operation type, gender, VDRP, preoperative BMI, and relative postoperative BMI-loss, however, only explain 24% of the variance in postoperative PTH levels. Other gastral or intestinal factors physiologically promoting calcium-turnover and PTH regulation are postulated.

[What can blind patients see in daily life with the subretinal Alpha IMS implant? Current overview from the clinical trial in Tübingen]

The subretinal visual implant is a scientific research approach to restore partial vision in end-stage hereditary retinal diseases by replacing the function of the degenerated photoreceptors by microelectronic chips. In a clinical trial in Tübingen these implants were tested on voluntary blind patients. By using the implants in daily living the patients reported valuable visual information. The subretinal microchip mediates subjectively useful visual information in near as well as in distant vision.

Cantilever arrays with self-aligned nanotips of uniform height

Cantilever arrays are employed to increase the throughput of imaging and manipulation at the nanoscale. We present a fabrication process to construct cantilever arrays with nanotips that show a uniform tip-sample distance. Such uniformity is crucial, because in many applications the cantilevers do not feature individual tip-sample spacing control. Uniform cantilever arrays lead to very similar tip-sample interaction within an array, enable non-contact modes for arrays and give better control over the load force in contact modes. The developed process flow uses a single mask to define both tips and cantilevers. An additional mask is required for the back side etch. The tips are self-aligned in the convex corner at the free end of each cantilever. Although we use standard optical contact lithography, we show that the convex corner can be sharpened to a nanometre scale radius by an isotropic underetch step. The process is robust and wafer-scale. The resonance frequencies of the cantilevers within an array are shown to be highly uniform with a relative standard error of 0.26% or lower. The tip-sample distance within an array of up to ten cantilevers is measured to have a standard error around 10 nm. An imaging demonstration using the AFM shows that all cantilevers in the array have a sharp tip with a radius below 10 nm. The process flow for the cantilever arrays finds application in probe-based nanolithography, probe-based data storage, nanomanufacturing and parallel scanning probe microscopy.

[Osteotendocutaneous radial forearm flap for hand reconstruction following circular saw injury]

Circular saw injuries may cause severe damage to the soft tissue of the hand, including destruction of skin, tendons and bone. We report the use of an osteotendocutaneous radial forearm flap for hand reconstruction following circular saw injury. This flap allowed simultaneous reconstruction of skin, tendon and osseous defect of the metacarpal bone.

[Immunosenescence. Current status and molecular mechanisms]

One of the most important biological changes occurring during human aging is termed 'immunosenescence' characterized by a functional decline in immunity leading to a progressive immunodeficiency. Regulatory mechanisms also are diminished, leading to an inefficient and poorly controlled pro-inflammatory activation of the immune response. This increases the risk for disorders such as infectious, autoimmune, neoplastic, cardiovascular and neurodegenerative disease. Many of these entities are quite relevant for dermatology. Hence, immunosenescence constitutes a pathologic process contributing to morbidity and mortality of important clinical relevance in an aging population. Investigation of the underlying pathomechanisms and the application of modern mechanism-directed therapy offer many opportunities for a targeted modulation and "rejuvenation", thus indicating possible targets for the reduction of age-associated morbidity and mortality. Some promising targeted 'molecular' therapies are already currently being used in the context of other diseases, also in the field of dermatology.

Evaluation of a VR and stereo-endoscopic tool to facilitate 3rd ventriculostomy

Endoscopic third ventriculostomy is a minimally invasive technique to treat hydrocephalus, which is a condition in which the patient is retaining excessive amount of cerebrospinal fluid in the head. While this surgical procedure is fairly routine, it carries some risks, mainly associated with the lack of depth perception, since monocular endoscopes provide only 2D views. We studied the advantages given by a 3D stereoendoscope over a 2D monocular endoscope, first by assessing the variability of stereoacuity in each subject, then in analyzing their overall correct response rate in differentiating between heights of two different images with 2D and 3D vision.

An integrated domain specific language for post-processing and visualizing electrophysiological signals in Java

Electrophysiology of vision - especially the electroretinogram (ERG) - is used as a non-invasive way for functional testing of the visual system. The ERG is a combined electrical response generated by neural and non-neuronal cells in the retina in response to light stimulation. This response can be recorded and used for diagnosis of numerous disorders. For both clinical practice and clinical trials it is important to process those signals in an accurate and fast way and to provide the results as structured, consistent reports. Therefore, we developed a freely available and open-source framework in Java (http://www.eye.uni-tuebingen.de/project/idsI4sigproc). The framework is focused on an easy integration with existing applications. By leveraging well-established software patterns like pipes-and-filters and fluent interfaces as well as by designing the application programming interfaces (API) as an integrated domain specific language (DSL) the overall framework provides a smooth learning curve. Additionally, it already contains several processing methods and visualization features and can be extended easily by implementing the provided interfaces. In this way, not only can new processing methods be added but the framework can also be adopted for other areas of signal processing. This article describes in detail the structure and implementation of the framework and demonstrate its application through the software package used in clinical practice and clinical trials at the University Eye Hospital Tuebingen one of the largest departments in the field of visual electrophysiology in Europe.

Automatic image guidance for prostate IMRT using low dose CBCT

PURPOSE

Varian's On-Board Imager is a linac-integrated cone-beam CT (CBCT) system used at the authors' institution to acquire images prior to delivering each fraction of prostate intensity modulated radiotherapy. The images are used to determine a couch shift that realigns the tumor with the position obtained in the planning CT. However, this manual image-guided radiotherapy (IGRT) technique is operator dependent, time consuming, offers limited degrees of freedom, and requires significant imaging dose over the course of treatment. To overcome these problems, the authors propose two fully automatic IGRT techniques that require significantly less imaging dose.

METHODS

Dose is reduced by lowering the x-ray tube mA s during CBCT acquisition at the cost of increasing image noise. In "forward" IGRT, the CBCT image is automatically registered to the planning CT to obtain the necessary couch shift. The "reverse" technique offers additional degrees of freedom as it involves nonrigid registration of the planning CT to the CBCT. Both techniques were evaluated using images of an anthropomorphic phantom with simulated motion and by retrospectively analyzing data from ten prostate cancer patients.

RESULTS

IGRT error for the phantom data at 100% relative imaging dose was 8.2 +/- 3.7, 3.5 +/- 1.2,, and 2.1 +/- 0.6 mm for setup only, forward, and reverse techniques, respectively. For patient images acquired at 100% relative imaging dose, the errors were 5.4 +/- 1.7, 5.0 +/- 1.6, 5.0 +/- 2.0, and 4.0 +/- 1.6 mm for setup only, manual forward (performed clinically), automatic forward, and reverse IGRT, respectively. Furthermore, imaging dose could be reduced to 20% without a significant loss in image guidance accuracy.

CONCLUSIONS

The presented image guidance methods are accurate while requiring only 20% of the standard imaging dose. The combination of low dose, automation, and accuracy enables frequent corrections during treatment, possibly leading to reduced margins and improved treatment outcomes.

Virtual reality imaging with real-time ultrasound guidance for facet joint injection: a proof of concept

Facet interventions continue to be used in pain management. Computed tomographic (CT) images can be registered into a virtual world that includes images generated by an ultrasound (US) probe tracked in real time, permitting guidance of tracked needles. We acquired CT-generated 3-dimensional (3D) images of 2 models and a cadaver. Three-dimensional representations of a US probe and needle were generated. A magnetic system tracked the needle and US probe. Using the US, 3D CT images were registered to the model/cadaver. Images were fused on a single interface. Facet injections were performed in the models and cadaver with radio-opaque markers. A postprocedure CT image determined appropriate placement. The virtual reality system described demonstrates technical innovations that may lead to future advancements in the area of percutaneous interventions in the management of pain.