Food Restriction in Anorexia Nervosa in the Light of Modern Learning Theory: A Narrative Review

Improvements in the clinical management of anorexia nervosa (AN) are urgently needed. To do so, the search for innovative approaches continues at laboratory and clinical levels to translate new findings into more effective treatments. In this sense, modern learning theory provides a unifying framework that connects concepts, methodologies and data from preclinical and clinical research to inspire novel interventions in the field of psychopathology in general, and of disordered eating in particular. Indeed, learning is thought to be a crucial factor in the development/regulation of normal and pathological eating behaviour. Thus, the present review not only tries to provide a comprehensive overview of modern learning research in the field of AN, but also follows a transdiagnostic perspective to offer testable explanations for the origin and maintenance of pathological food rejection. This narrative review was informed by a systematic search of research papers in the electronic databases PsycInfo, Scopus and Web of Science following PRISMA methodology. By considering the number and type of associations (Pavlovian, goal-directed or habitual) and the affective nature of conditioning processes (appetitive versus aversive), this approach can explain many features of AN, including why some patients restrict food intake to the point of life-threatening starvation and others restrict calorie intake to lose weight and binge on a regular basis. Nonetheless, it is striking how little impact modern learning theory has had on the current AN research agenda and practice.

Anatomical risk factors for aseptic loosening of full hinge knee prosthesis in primary and revision TKAs

INTRODUCTION

Risk factors (RF) associated with aseptic loosening (AL) in total knee arthroplasty (TKA) are poorly understood. Therefore, the aim of this study was to investigate the anatomical shape variations in relation to the inner-diameter of the femur and the tibia as prognostic RF for AL of full hinge prosthesis (FHP) in primary and revision TKA.

MATERIALS AND METHODS

We retrospectively examined all patients, who underwent revision surgery (2003-2018) due to AL of the FHP in primary (n = 38) and revision TKA (n = 46). Diagnosis-appropriate controls without AL at minimum follow-up of 24 months were randomly collected for each group. Besides other risk factors, we also measured the inner diameter of the femur according to the Citak classification and of the tibia on anteroposterior radiographies.

RESULTS

RF for AL are younger age in primary and revision as well as > 1 previous surgeries in revision TKA. The femoral index was shown to be a RF for AL in revision TKA (p = 0.001), but not in primary TKA. The novel tibial index was associated with AL in primary with AUC 0.776 (95% CI 0.67, 0.88), 65.8% sensitivity, 86.6% specificity and in revision TKA with AUC 0.817 (95% CI 0.73, 0.91), 82.6% sensitivity and 71.7% specificity.

CONCLUSION

This is the first study to calculate the tibial measurements and the tibial index according to Citak et al. and to identify them as prognostic RF for AL of the full hinge knee prosthesis in TKA and confirm the femoral index as a RF for AL also in revision full hinge knee prosthesis. Therefore, the preoperative radiological evaluation should include the analysis of the anatomical shape variants in order to select the appropriate prosthesis design with a possibly enhanced prognosis.

Early postoperative endoscopic evaluation of rectal anastomoses: a prospective cross-sectional study

BACKGROUND

Reported incidence of anastomotic leakage (AL) of rectal anastomoses is up to 29% with an overall mortality up to 12%. Nevertheless, there is no uniform evidence-based diagnostic procedure for early detection of AL. The objective of this prospective clinical trial was to demonstrate the diagnostic value of early postoperative flexible endoscopy for rectal anastomosis evaluation.

METHODS

Flexible endoscopy between 5 and 8th postoperative day was performed consecutively in 90 asymptomatic patients. Sample size calculation was made using the two-stage Simon design. Diagnostic value was measured by management change after endoscopic evaluation. Anastomoses were categorized according to a new classification. Study is registered in German Clinical Trials Register (DRKS00019217).

RESULTS

Of the 90 anastomoses, 59 (65.6%) were unsuspicious. 20 (22.2%) were suspicious with partial fibrin plaques (n = 15), intramural hematoma and/or local blood coagulum (n = 4) and ischemic area in one. 17 of these anastomoses were treated conservatively under monitoring. In three a further endoscopic re-evaluation was performed and as consequence one patient underwent endoscopic vacuum therapy. 11 (12.2%) AL were detected. Here, two could be treated conservatively under monitoring, four with endoscopic vacuum therapy and five needed revision surgery. No intervention-related adverse events occurred. A change in postoperative management was made in 31 (34.4%) patients what caused a significant improvement of diagnosis of AL (p < 0.001).

CONCLUSIONS

Early postoperative endoscopic evaluation of rectal anastomoses is a safe procedure thus allows early detection of AL. Early treatment for suspicious anastomoses or AL could be adapted to avoid severe morbidity and mortality.

Impact of preoperative body mass index and weight loss on morbidity and mortality following colorectal cancer-a retrospective cohort study

PURPOSE

Body weight and preoperative weight loss (WL) are controversially discussed as risk factors for postoperative morbidity and mortality in colorectal cancer surgery. The objective of this study is to determine whether body mass index (BMI) or WL is associated with a higher postoperative complication rate.

METHODS

In this retrospective cohort study, data analysis of 1241 consecutive patients undergoing colorectal cancer surgery in an 11-year period was performed. The main outcome measures were wound infections (WI), anastomotic leakages (AL), and in-house mortality.

RESULTS

A total of 697 (56%) patients with colon and 544 (44%) with rectum carcinoma underwent surgery. The rate of WI for each location increased with rising BMI. The threshold value was 28.8 kg/m2. Obese patients developed significantly more WI than normal-weight patients did following rectal resection (18.0% vs. 8.2%, p = 0.018). Patients with preoperative WL developed significantly more AL following colon resections than did patients without preoperative WL (6.2% vs. 2.5%, p = 0.046). In-house mortality was significantly higher in obese patients following colon resections than in overweight patients (4.3% vs. 0.4%, p = 0.012). Regression analysis with reference to postoperative in-house mortality revealed neither increased BMI nor WL as an independent risk factor.

CONCLUSIONS

Increased preoperative BMI is associated with a higher WI rate. AL rate after colon resection was significantly higher in patients showing preoperative WL. Preoperative BMI and WL are therefore risk factors for postoperative morbidity in this study. Nevertheless, this has to be further clarified by means of prospective studies. Trial registration DRKS00025359, 21.05.2021, retrospectively registered.

Enhancing the radiological classification system from the distal femur to the proximal tibia

Objectives

Patients and methods

Results

Conclusion

[Laparoscopic Heller Myotomy in the Treatment of Achalasia]

BACKGROUND

Achalasia refers to a primary oesophageal motility disorder characterised by the absence of peristalsis and incomplete or complete lack of relaxation of the lower oesophageal sphincter. The cardinal symptom is dysphagia. The therapeutic goal is surgical or interventional repair of the oesophageal outflow tract at the level of the oesophagogastric junction.

INDICATION

We present the case of a 24-year-old patient with dysphagia accompanied by regurgitations, odynophagia as well as an unintentional weight loss over two years.

METHODS

The video describes the preoperative imaging as well as endoscopic findings and demonstrates the technique of laparoscopic Heller myotomy followed by Dor fundoplication.

CONCLUSIONS

Concerning the therapy of classic achalasia, laparoscopic Heller myotomy followed by Dor fundoplication - despite controversies regarding peroral endoscopic myotomy as an alternative therapeutic option - can be considered as an established standard procedure.

Reducing Degrees of Freedom in Surgical Suturing: Implications for Minimally Invasive Device Development-A Prospective Experimental Study

Open surgery allows the use of all 6 degrees of freedom (DOF; x-y-z and roll-pitch-yaw), whereas laparoscopy requires working under limitation to 4 axes. We present a prospective experimental study evaluating translational and rotational DOF restriction in surgical suturing tasks. An experimental platform included a kinematic structure that limited the maneuverability of the surgical instruments. The subjects (n=20) worked in a randomized order using (1) 6DOF, (2) 4DOF with 3 translational and 1 rotational DOF (4TRANS), and (3) 4DOF with 1 translational and 3 rotational DOF (4ROT). The time required to perform each task was recorded. Suturing and knot tying were significantly faster under 6DOF compared with 4ROT (both P<0.001) and 4TRANS (both P<0.001). Assessment of subjective difficulty and impairment showed most favorable results for 6DOF. The advantage of rotational compared with translational DOF should be considered in the development of future surgical devices.

Detection of adverse events leading to inadvertent injury during laparoscopic cholecystectomy using convolutional neural networks

Uncontrolled movements of laparoscopic instruments can lead to inadvertent injury of adjacent structures. The risk becomes evident when the dissecting instrument is located outside the field of view of the laparoscopic camera. Technical solutions to ensure patient safety are appreciated. The present work evaluated the feasibility of an automated binary classification of laparoscopic image data using Convolutional Neural Networks (CNN) to determine whether the dissecting instrument is located within the laparoscopic image section. A unique record of images was generated from six laparoscopic cholecystectomies in a surgical training environment to configure and train the CNN. By using a temporary version of the neural network, the annotation of the training image files could be automated and accelerated. A combination of oversampling and selective data augmentation was used to enlarge the fully labeled image data set and prevent loss of accuracy due to imbalanced class volumes. Subsequently the same approach was applied to the comprehensive, fully annotated Cholec80 database. The described process led to the generation of extensive and balanced training image data sets. The performance of the CNN-based binary classifiers was evaluated on separate test records from both databases. On our recorded data, an accuracy of 0.88 with regard to the safety-relevant classification was achieved. The subsequent evaluation on the Cholec80 data set yielded an accuracy of 0.84. The presented results demonstrate the feasibility of a binary classification of laparoscopic image data for the detection of adverse events in a surgical training environment using a specifically configured CNN architecture.

Learning curves, potential and speed in training of laparoscopic skills: a randomised comparative study in a box trainer

Background

The effectiveness of practical surgical training is characterised by an inherent learning curve. Decisive are individual initial starting capabilities, learning speed, ideal learning plateaus, and resulting learning potentials. The quantification of learning curves requires reproducible tasks with varied levels of difficulty. The hypothesis of this study is that the use of three-dimensional (3D) vision is more advantageous than two-dimensional vision (2D) for the learning curve in laparoscopic training.

Methods

Forty laparoscopy novices were recruited and randomised to a 2D Group and a 3D Group. A laparoscopy box trainer with two standardised tasks was used for training of surgical tasks. Task 1 was a positioning task, while Task 2 called for laparoscopic knotting as a more complex process. Each task was repeated at least ten times. Performance time and the number of predefined errors were recorded. 2D performance after 3D training was assessed in an additional final 2D cycle undertaken by the 3D Group.

Results

The calculated learning plateaus of both performance times and errors were lower for 3D. Independent of the vision mode the learning curves were smoother (exponential decay) and efficiency was learned faster than precision. The learning potentials varied widely depending on the corresponding initial values and learning plateaus. The final 2D performance time of the 3D-trained group was not significantly better than that of the 2D Group. The final 2D error numbers were similar for all groups.

Conclusions

Stereoscopic vision can speed up laparoscopic training. The 3D learning curves resulted in better precision and efficiency. The 3D-trained group did not show inferior performance in the final 2D cycle. Consequently, we encourage the training of surgical competences like suturing and knotting under 3D vision, even if it is not available in clinical routine.

Endoscopic projection of the gastroduodenal artery: Anatomical implications for bleeding management

INTRODUCTION

Peptic ulcers account for 50% of upper gastrointestinal bleeding incidents. Bleedings from large vessels, such as the gastroduodenal artery, are associated with increased mortality. Ulcers located on the posterior wall of the duodenum show the highest risk for erosion of the gastroduodenal artery. Endoscopic management is challenging and rebleeding rates are high due to internal and external confounding factors such as anatomical variability and gastric insufflation. We aimed to correlate macroscopic and endoscopic anatomy for assessment of implications for clinical management.

MATERIAL AND METHODS

The gastroduodenal artery was dissected in 10 anatomical specimens. The points of contact of the artery with the posterior wall of the duodenum were marked with needles. The endoluminal position of the needles was recorded by standardized gastroscopy and a 3-dimensional virtual reconstruction was carried out for visualization of the artery's course.

RESULTS

The artery's proximal and distal points of contact with the duodenum were 27.2mm (range 15-30mm; SD 6.7mm) and 15mm (range 10-20mm; SD 3.5mm), respectively, from the pylorus. The gastroduodenal artery branches from the common hepatic artery within the omentum minus running adjacent to the duodenal wall to the head of the pancreas. From endoscopic perspective, the gastroduodenal artery's course was directed towards the tip of the gastroscope.

CONCLUSION

Due to the peculiar extraluminal course of the gastroduodenal artery the arterial blood flow projects into the direction of the gastroscope during endoscopic intervention. Measures for bleeding control might have to be applied aboral from the bleeding site.

Therapy of pessary-induced rectovaginal fistula and pelvic organ prolapse in elderly patients by vaginal approach and modified LeFort colpocleisis: a case series

PURPOSE

Pelvic organ prolapse (POP) presents a common benign condition in women associated with reduced quality of life (QoL). The use of pessaries is considered a first-line treatment of POP. However, pessaries can cause perforations into adjacent organs resulting in fistulas. We present a series of three cases of rectovaginal fistulas (RVF) due to pessary perforation.

METHODS

Three consecutive cases of pessary-induced RVF in patients with POP stage IV were assessed between September 2016 and September 2019. Consensus for therapeutic strategy was reached by an interdisciplinary board.

RESULTS

The RVF were located in the posterior vaginal wall and had a diameter of up to 60 mm. In one of three patients, a two-step approach was chosen with the ostomy being performed at the same time as fistula closure and modified LeFort colpocleisis. It was followed by ostomy closure 3 months later. In two patients, a three-step approach was chosen with the ostomy performed separately due to a local tissue inflammation around RVF. Neither fistula nor POP recurrences have occurred so far.

CONCLUSION

Combined temporary gastrointestinal diversion, RVF closure and POP therapy can be performed as a two- or three-stage approach. Lack of evidence and standardized algorithms in RVF therapy make further clinical studies essential. We encourage the preoperative assessment of any case of complex rectovaginal fistula by an interdisciplinary board for determining an individualized treatment.

TuThor: an innovative new training model for video-assisted thoracic surgery

OBJECTIVES

Video-assisted thoracic surgery (VATS) is a complex technique requiring dedicated surgical training. Platforms for such training are scarce and often rely on the use of live animals, which raises ethical concerns. The objective of this study was to develop a box trainer that is dedicated for VATS training and able to reproduce bleeding scenarios.

METHODS

The developed Tuebingen Thorax Trainer comprises 5 components that are mounted on a human anatomy-like thoracic cavity containing a porcine organ complex. Any standard thoracoscopic instrument can be used. The organ complex is attached to a perfusion module. We assessed the applicability of the system in four 1-day VATS training courses at the Tuebingen Surgical Training Center. Assessment was performed using a questionnaire handed out to all participants.

RESULTS

Forty participants have been trained with the Tuebingen Thorax Trainer at our institution since November 2016. Thirty-five (87.5%) participants stated that the Tuebingen Thorax Trainer is an adequate model for VATS training. The ex vivo organ complex was reported to be realistic with regards to the level of detail and scale (76%). A large proportion of participants (27.5%) were experienced with VATS and reported having performed >50 procedures before taking the training course.

CONCLUSIONS

This new training device allows realistic training for VATS procedures. 'Stagnant hydrostatic perfusion' permits simulation of reproducible bleeding scenarios. The device is low in production costs and offers a strong resemblance to the clinical scenario. It reduces the use of animal models and contributes to the efforts in making surgical skills training for VATS more accessible.

Ultrafast Single-Molecule Fluorescence Measured by Femtosecond Double-Pulse Excitation Photon Antibunching

Most measurements of fluorescence lifetimes on the single-molecule level are carried out using avalanche photon diodes (APDs). These single-photon counters are inherently slow, and their response shows a strong dependence on photon energy, which can make reconvolution of the instrument response function (IRF) challenging. An ultrafast time resolution in single-molecule fluorescence is crucial, e.g., in determining donor lifetimes in donor-acceptor couples which undergo energy transfer, or in plasmonic antenna structures, where the radiative rate and non-radiative rates are enhanced. We introduce a femtosecond double-excitation (FeDEx) photon correlation technique, which measures the degree of photon antibunching as a function of time delay between two excitation pulses. In this boxcar integration, the time resolution of fluorescence transients is limited solely by the laser pulse length and is independent of the detector IRF. The versatility of the technique is demonstrated with a custom-made donor-acceptor complex with one donor and two acceptors and with single dye molecules positioned accurately between two gold nanoparticles using DNA origami. The latter structures show ∼75-fold radiative-rate enhancement and fluorescence lifetimes down to 19 ps, which is measured without the need for any reconvolution. With the potential of measuring subpicosecond fluorescence lifetimes, plasmonic antenna structures can now be optimized further.

[Robotic Assisted Proctocolectomy with Ileal Pouch-Anal Anastomosis in a Case of Suspected Hereditary Polyposis]

BACKGROUND

Various forms of hereditary polyposis have been described in the literature. Classical familial adenomatous polyposis (FAP) is a rare, autosomal dominantly inherited disease which is caused by a germline mutation in the adenomatous polyposis coli gene (APC). Patients with this diagnosis successively develop multiple polyps of the colon. Left untreated, FAP almost inevitably leads to malignant transformation.

INDICATION

We present the case of a 37-year-old patient with histologically confirmed, stenotic adenocarcinoma of the descending colon and an initially suspected hereditary polyposis due to multiple polyps in the descending and sigmoid colon.

METHODS

The video describes the preoperative imaging as well as endoscopic findings and demonstrates the technique of a two-stage, robotically assisted proctocolectomy with ileal pouch-anal anastomosis (IPAA) and the creation of a temporary loop ileostomy.

CONCLUSIONS

With respect to the surgical treatment of classic FAP, restorative proctocolectomy (RPC) with ileal J-pouch construction can be regarded as an established standard procedure, despite controversy regarding various technical aspects. Minimally invasive strategies should be considered as an equivalent option compared to conventional techniques.

Novel box trainer for taTME - prospective evaluation among medical students

Background

Transanal total mesorectal excision (taTME) has been subject to extensive research and increasing clinical application. It allows further reduction of trauma by accessing via a natural orifice. Manifold platforms and instruments have been introduced and heterogeneity in surgical techniques exists. Because of the technique’s complexity there is a persistent need for dedicated training devices and concepts.

Materials and methods

The key steps of taTME were analyzed and a box trainer with three modules resembling these steps was designed and manufactured. Twenty-one surgically inexperienced medical students performed five repetitions of the three tasks with the new box trainer. Time and error count were analyzed for assessment of a learning curve.

Results

A significant reduction of processing time could be demonstrated for tasks 1–3 (p < 0.001; p < 0.001; p = 0.001). The effect size was high for comparison of repetition 1 and 5 and decreased over the course (task 1: r = 0.88 vs. r = 0.21; task 2: r = 0.86 vs. r = 0.23; task 3: r = 0.74 vs. r = 0.44). Also, a significant reduction of errors was demonstrated for tasks 1 and 2. The decrease of effect size was analogously demonstrated.

Conclusions

The trainer might help to reduce the use of animal models for testing of platforms and instruments as well as gaining first-hand experience in transanal rectal resection.

[First Robotic Assisted Resection of a Retrorectal Tailgut Cyst - Video Case Report of a 27-Year-Old Female Patient]

PURPOSE

Tailgut cysts are a rare form of retrorectal tumours. They are also referred to as cystic hamartomas and predominantly affect female patients. Malignant transformation is thought to occur in 2 - 10% of cases, but there is scant further evidence. Besides the risk of malignant transformation, the feared complications include infection, difficulties in defecation, or potential dystocia necessitating in sano resection.

INDICATION

We describe the case of a 27-year-old female patient presenting with a prolapsing round structure during defaecation. MRI, endosonography and transrectal drainage were carried out to exclude malignancy. We performed resection of the retrorectal tailgut cyst by robotic surgery. To the authors knowledge, this access has not previously been described for tailgut cyst resection.

METHOD

Our video shows preoperative diagnostic testing, endoscopic drainage and robotic resection of the tailgut cyst. An intraoperative lesion of the dorsal rectum was successfully closed by suture.

CONCLUSIONS

Different surgical techniques have been described for tailgut cyst resection. That with the widest application is posterior/sacral access, followed by abdominal and transrectal techniques. There are no published reports of robotic resection. We chose the robotic approach, as this is the surgeon's preferred technique for minimally invasive surgery of the pelvis.

Anomalous Linear Dichroism in Bent Chromophores of π-conjugated Polymers: Departure from the Franck-Condon Principle

We examine the influence of bending of π-conjugated chromophores on photoluminescence (PL) by spectrally resolving the depolarization of fluorescence on the single-molecule level. The effect of excited-state mixing mediated by molecular vibrations is manifested in the departure from the usual achromatic linear dichroism of fluorescence, with the polarization anisotropy decreasing in the vibronic progression. Bent chromophores reveal an overall increase in vibronic PL intensity with polarization orthogonal to the molecular long axis. This manifestation of the Renner-Herzberg-Teller (RHT) effect illustrates the breakdown of the Franck-Condon principle in macromolecules used in organic electronics, providing information on the orientation of transition-dipole moments and the origin of spectral broadening. While some of the spectral signatures of the RHT effect appear similar to those of H aggregation in molecular dimers, discrimination between the two phenomena is straightforward since H aggregation does not induce anomalous linear dichroism.

Enterocutaneous fistula in severely active Crohn's disease: preoperative anti-TNF alpha treatment to limit bowel resection-report of a case

PURPOSE

Strategies for limiting the extent of bowel resection in cases of enterocutaneous or interenteric fistulas in severely active Crohn's disease are urgently necessary. Anti-inflammatory therapy with tumor necrosis factor alpha (anti-TNF alpha) inhibitors has positive impact on fistulizing Crohn's disease. We describe a case of a 32-year-old male suffering from enterocutaneous fistula in severely active Crohn's disease.

METHODS

The patient's clinical course and data of therapy monitoring before bowel resection were reviewed and compared to the pretherapeutic findings. In addition, the reports of surgery and histopathological workup were evaluated and a clinical follow-up was performed. The literature on anti-TNF alpha treatment in fistulizing Crohn's disease was surveyed.

RESULTS

A 32-year-old male with an 8-year history of Crohn's disease and condition after previous ileocecal and sigmoid resection at the age of 28 presented with increasing pain in the middle-right abdomen. Laboratory and radiologic assessment detected elevated C-reactive protein and presence of a conglomerate of inflammatory thickened and narrowed small intestine involving the neoterminal ileum and enteroenteric fistulas. Ileocolonoscopy showed a stenosing inflammation of the neoterminal ileum. After initial anti-infective therapy, as a result of an interdisciplinary decision, preoperative anti-TNF alpha treatment was performed to achieve limited bowel resection. After declining of inflammation, limited bowel resection was carried out successfully.

CONCLUSIONS

Preoperative therapy with anti-TNF alpha might potentially reduce inflammation to subsequently limit the extent of bowel resection in selected cases of enterocutaneous or interenteric fistulas in severely active Crohn's disease. We describe an impressive case in which such therapeutic approach was carried out.

Effects of Institutionalization and Parental Living Status on Children's Self-Esteem, and Externalizing and Internalizing Problems in Rwanda

The negative effects of institutionalization on children's wellbeing and psychological adjustment have been extensively documented. Throughout the world, particularly in developing countries, many children in residential child care institutions known as orphanages have parents, and it is not clear how this situation affects the psychological adjustment of institutionalized children. This study aimed at investigating specifically whether institutionalization impacts negatively children's psychological adjustment defined in terms of externalizing and internalizing behavior problems and self-esteem and whether having living parents or not has an additional influence. Children were recruited in Rwanda from seven registered institutions and six primary schools. Ninety-six institutionalized children (48 orphans, who lost at least one parent, and 46 non-orphans, who had both parents living) and 84 non-institutionalized children, who lived in a family (28 orphans and 56 non-orphans) aged 9 to 16 participated. The caregivers or parents assessed externalizing and internalizing behavior problems using the Child Behavior Checklist. Children completed the Coopersmith Self-Esteem Inventory. Controlling for gender, age, and residential area, analyses of covariance revealed that institutionalized children had significantly more externalizing behavior problems than had non-institutionalized children. In addition, non-orphans had more externalizing behavior problems than had orphans, regardless of whether they lived in an institution or not. There were no group differences in internalizing behavior problems, but there was a significant main effect of the parental living status (orphans vs. non-orphans) and a significant interaction effect between parental living status and institutionalization on self-esteem. Self-esteem of non-orphans in families was significantly higher than self-esteem of the other groups. This should be considered when making the decision to place a child in an institution, especially when her or his parents are still living, and when developing supportive programs for children without adequate parental care.

Thought-shape fusion in young healthy females appears after vivid imagination of thin ideals

BACKGROUND AND OBJECTIVES

It has been shown that exposure to female thin ideals in media has minimal to moderate direct effects on body image satisfaction (BIS), mood and dysfunctional eating in healthy young women. Evidence has been found for several intervening variables such as social comparison processes. Accordingly it is assumed, that cognitive processing (rather than mere media exposure) is crucial. Consequently, vivid imagination of thin ideals after exposure to a fashion magazine was induced in order to trigger cognitive processes. Changes in mood, BIS and resulting bodyrelated cognitive distortions (Thought-Shape Fusion Body, TSF-B) were assessed.

METHODS

A total of 91 healthy women (mean age 21.9 years, SD = 2.0) were exposed to either a fashion magazine (thin-ideal group) or a nature magazine (control group) in a waiting room design. Afterwards they were instructed to vividly imagine either the thin ideals or landscapes.

RESULTS

When exposed to thin ideals, a significant decrease in mood and BIS emerged after vivid imagination, but not after mere magazine exposure. Imagining thin ideals triggered body-related cognitive distortions (TSF-B). A higher degree of eating disorder (ED) symptomatology amplified this effect.

LIMITATIONS

These findings apply to young healthy females and cannot be generalized to samples with obesity, EDs or males. Internal validity is limited since the intensity of the exposure has not been systematically controlled.

CONCLUSIONS

Vivid imagination of thin ideals promoted by magazines results in impaired mood and BIS and moreover in body-related cognitive distortions (TSF-B) in healthy women, especially, for those with stronger ED symptomatology.

Monitoring a mouse colony for Helicobacter bilis using a Helicobacter-genus-specific nested PCR

Although Helicobacter infections of laboratory mice are usually subclinical, they may interfere with in vivo experiments and thus may lead to misinterpretation of data. As such, it is important to provide a means to unequivocally identify infections with murine Helicobacter spp. In the present study, a nested polymerase chain reaction (PCR) was established and shown to be 10 to 100 times more sensitive than the single-step PCR commonly used for routine diagnosis of Helicobacter spp. Experimental infection of Helicobacter-free mice demonstrated that faeces, caecum, colon and rectum but not liver are equally suitable for the detection of H. bilis. However, use of faecal pellets is advantageous since detection of H. bilis is possible one week after infection and analysis of faeces instead of tissues avoids euthanasia of animals. Furthermore, it generates representative data for all animals housed in the same cage and analysis can be repeatedly performed. Use of samples from breeding pairs but not offspring provides representative information about the Helicobacter status of a mouse colony. Both C3H/HeJ and C57BL/6 mice appear to be susceptible to H. bilis and persistent infection was observed during the 20-week experimental period. Analysis of pooled faecal pellets by nested PCR seems to be the most sensitive approach for H. bilis monitoring of the given breeding colony.

Performance evaluation of IVC systems

An expert Working Group was set up in December 2000 to develop recommendations for users and industry on the evaluation of proper function and operation of individually ventilated cage (IVC) systems. The full report of their recommendations is in two parts—'Part 1: Test Instructions' and 'Part 2: Evaluation Criteria'—both of which have been published in full on the Laboratory Animals Ltd website. They can be found at http://www.lal.org.uk/IVC/index.html. Evaluation of and feedback on the recommendations to further refine their use and scientific basis is encouraged. This Summary Report provides a brief overview of the background to the development of the full report and the issues it addresses.

The cryogenic storage ring CSR

An electrostatic cryogenic storage ring, CSR, for beams of anions and cations with up to 300 keV kinetic energy per unit charge has been designed, constructed, and put into operation. With a circumference of 35 m, the ion-beam vacuum chambers and all beam optics are in a cryostat and cooled by a closed-cycle liquid helium system. At temperatures as low as (5.5 ± 1) K inside the ring, storage time constants of several minutes up to almost an hour were observed for atomic and molecular, anion and cation beams at an energy of 60 keV. The ion-beam intensity, energy-dependent closed-orbit shifts (dispersion), and the focusing properties of the machine were studied by a system of capacitive pickups. The Schottky-noise spectrum of the stored ions revealed a broadening of the momentum distribution on a time scale of 1000 s. Photodetachment of stored anions was used in the beam lifetime measurements. The detachment rate by anion collisions with residual-gas molecules was found to be extremely low. A residual-gas density below 140 cm(-3) is derived, equivalent to a room-temperature pressure below 10(-14) mbar. Fast atomic, molecular, and cluster ion beams stored for long periods of time in a cryogenic environment will allow experiments on collision- and radiation-induced fragmentation processes of ions in known internal quantum states with merged and crossed photon and particle beams.

Severe accident research activities at Helmholtz-Zentrum Dresden-Rossendorf (HZDR)

In the frame of the nuclear safety research program of the Helmholtz Association HZDR performs fundamental and applied research to assess and to reduce the risks related to the nuclear fuel cycle and the production of electricity in nuclear power plants. One of the research topics focuses on the safety aspects of current and future reactor designs. This includes the development and application of methods for analyses of transients and postulated accidents, covering the whole spectrum from normal operation till severe accident sequences including core degradation. This paper gives an overview of the severe accident research activities at the Reactor Safety Division at the Institute of Resource Ecology.

Pure Natural Orifice Transluminal Endoscopic Surgery (NOTES) with a new elongated, curved Transanal Endoscopic Operation (TEO) device for rectosigmoid resection: a survival study in a porcine model

BACKGROUND

Natural orifice transluminal endoscopic surgery (NOTES) has seen considerable new developments in its evolution to a platform for rectal and sigmoid resection, but to date no true single NOTES procedure has been convincing. This study investigates the safety and feasibility of a further developed transanal NOTES platform for single-access NOTES rectosigmoid resection.

METHODS

Ten large female pigs, mean weight 99.3 kg [standard deviation (SD) 7 kg, range 85.1-112.6 kg], underwent transanal rectosigmoid resection. Five animals were included in an acute study group with immediate postoperative euthanization. A second group included five animals in a survival study. Transanal rectosigmoid resections were performed with an elongated and curved transanal endoscopic operation (TEO) device. Coloanal anastomosis was performed using the transanal circular stapler technique. Survival follow-up was at 7 and 28 days via colonoscopy under sedation.

RESULTS

Single-access NOTES transanal rectosigmoid resection with coloanal anastomosis was performed in nine out of ten female pigs. Mean length of rectosigmoid specimens exteriorized was 18.7 cm (SD 2.9 cm, range 14-23 cm). Mean operating time was 124 min (SD 35.7 min, range 70-166 min). Within the survival group, no complications occurred during the monitoring phase. In one case, there was ascites and colitis at necropsy as well as fibrosis at the anastomosis site.

CONCLUSIONS

Pure transanal rectosigmoid resection is a feasible procedure. The approach via a single transanal access is demanding but viable with the elongated and curved TEO device. The newly developed scope offers an excellent view of the area cephalad to the promontory.

Diagnostic accuracy of hyperbilirubinaemia in anticipating appendicitis and its severity

BACKGROUND

Hyperbilirubinaemia is reported to be a positive predictor in diagnosing appendicitis and especially appendiceal perforation. We, therefore, analysed the diagnostic accuracy of serum bilirubin in anticipating appendicitis and its severity.

METHODS

All consecutive patients undergoing appendectomy for suspected appendicitis from May 2009 to August 2011 were analysed. Patients were classified based on final histopathological findings into the groups: no appendiceal inflammation, non-perforated appendicitis and perforated appendicitis. Primary outcome was the diagnostic accuracy of serum bilirubin levels in discriminating between no appendiceal inflammation and any appendicitis (perforated and non-perforated appendicitis) and non-perforated and perforated appendicitis.

RESULTS

Of 493 analysed patients, 125 (25%) had no appendiceal inflammation, 312 (64%) had non-perforated appendicitis and 56 (11%) had perforated appendicitis. The proportion of patients with bilirubin elevation (>1.1 mg/dL) was different between those with no appendiceal inflammation (14%) and any appendicitis (36%) (p<0.0001), and between non-perforated appendicitis and perforated appendicitis 48% (p=0.04). However, the positive and negative likelihood ratios (LRs) for an elevated bilirubin were poor at discriminating the groups: no appendiceal inflammation versus any appendicitis (LR+ 2.62 (95% CI 1.65 to 4.16) and LR- 0.75 (95% CI 0.67 to 0.83)) and non-perforated appendicitis versus perforated appendicitis (LR+ estimate 1.74 (95% CI 1.28 to 2.38) and LR- 0.72 (95% CI 0.55 to 0.93)).

CONCLUSIONS

Hyperbilirubinaemia is present in acute appendicitis but has a low diagnostic accuracy in discriminating between any appendicitis versus no appendiceal inflammation and perforated versus non-perforated appendicitis and is, therefore, of limited value in clinical routine.

TRIAL REGISTRATION NUMBER

NCT01698099.

Use of self-retaining barbed suture for rectal wall closure in transanal endoscopic microsurgery

BACKGROUND

The aim of this study was to investigate the safety and efficacy of self-retaining barbed sutures in comparison with monofilament clip-fixated sutures for rectal wall closure in transanal endoscopic microsurgery.

METHODS

Horizontal full-thickness wall defects (3.5 cm) of cattle rectal specimens were closed via transanal endoscopic microsurgery using a monofilament suture with clips at the end (Surgipro(®) 2/0; Covidien, Mansfield, MA, USA, n = 25) or a self-retaining barbed suture (V-Loc™ 180 3/0; Covidien, Mansfield, MA, USA, n = 25). The primary endpoint was the pneumatic leakage pressure of the suture line. As a secondary endpoint, suture time was evaluated.

RESULTS

The median pneumatic leakage pressure for barbed sutures was 45.5 mbar (range 17-106 mbar) and 33.5 mbar (range 19-106 mbar) for monofilament sutures (p = 0.58). A pneumatic leak at a critical pressure below 25 mbar occurred in 3 cases with barbed sutures and in 7 cases with monofilament sutures (p = 0.29). Median suturing time [19:25 min:s (range 12:00-33:30) vs. 20:41 (17:00-28:33), p = 0.23] did not differ between the two groups.

CONCLUSIONS

Barbed sutures display the same bursting pressure as monofilament sutures and their use for rectal wall closure seems feasible.

Technical complications during removal of locking screws from locking compression plates: a prospective multicenter study

PURPOSE

To assess the risk for technical complications in patients undergoing removal of locking compression plates (LCP) with head locking screws.

METHODS

A total of 205 patients who were scheduled for implant removal surgery after a healed fracture of the femur, tibia, humerus, distal radius, or clavicle in nine Austrian clinics were prospectively included in the study, all of whom had previously undergone fracture fixation by plates, with titanium implants used in 98 % of the patients. Intraoperative technical complications and the methods used to solve them were documented by the surgeon.

RESULTS

During the course of this study, a total of 1,462 locking screws were removed from 204 LCPs. While 95 % of these screws could be removed without difficulties, technical complications were reported for 41 patients with 78 screws which could not be removed with standard screwdrivers and required the use of additional instruments. The estimated risk for the occurrence of at least one technical complication during implant removal surgery was 20.1 %. The most frequently observed complications were screws that could not be loosened because they were jammed in the LCP, screws with a damaged recess in which the screwdriver turned freely, as well as a combination of both events. The majority of these screws could be removed with the use of a conical extraction screw or by drilling off the screw head. In one patient, an intraoperative refracture of the humerus occurred during plate removal. Even though there is a rate of 20 % for technical complications when removing the implants, only a few patients experience a clinical impact.

CONCLUSIONS

Titanium LCPs are prone to technical complications during implant removal, but the majority of the issues can be solved using special techniques.

[The effect of energy drinks on the cognitive performance of adolescents]

BACKGROUND

Manufacturers of energy drinks claim that their drinks can have a positive effect on cognitive performance. So far, there is little evidence that energy drinks do in fact enhance the cognitive performance of adolescents.

AIM

To find out, via a series of tests, whether the manufacturers of energy drinks are justified in claiming that their drinks improve the cognitive performance of young people.

METHOD

In a quasi-experimental design a number of young people (aged 15-18) were divided into three groups: a control group, each of whose members drank water beforehand; a placebo group whose members drank a glass of sugar-free lemonade, and an experimental group whose members drank a currently available energy drink (Megaforce). Pencil and paper tests were administered to the members of each group in order to measure attention and concentration, learning ability, memory, verbal and numerical reasoning, numerical aptitude and vocabulary.

RESULTS

No significant differences between groups were found that could solely be ascribed to the effect of energy drink.

CONCLUSION

Given the warnings about the potential health-risks of energy drinks and the fact that no evidence was found for positive effects of energy drinks on the cognitive performance of young people, we are of the opinion that youngsters should stay away from such drinks.

Formation of liquid and solid products from liquid phase pyrolysis

The aim of the present work was to improve the C:O ratio in biomass by preserving the lignin macrostructure of lignocellulosic feed. The intention of liquid phase pyrolysis is to liquefy biomass and prepare biomass for further upgrading steps like hydrogenation and deoxygenation. Pyrolysis was carried out in a non-aqueous liquid phase heat carrier. The process was carried out in a semi-batch reaction vessel under isothermal conditions at T=350°C, supported by a quench to stop reactions instantaneously in order to observe formation of solid intermediates. This pyrolysis system enables the observation of liquid and solid product formation. Transformation of biomass into biochar was analyzed by infrared spectroscopy and elemental analysis. Stable lignin structure throughout the whole transformation was confirmed. It was shown that the lignin frame in wood remains without substantial loss, while the major amount of carbohydrates is pyrolyzed during liquid phase pyrolysis at T=350°C.

Transanal endoscopic microsurgery-based transanal access for colorectal surgery: experience on human cadavers

Transanal endoscopic microsurgery (TEM) was described in 1983 for local excision of rectal tumors. In the context of natural orifice translumenal endoscopic surgery, we have modified the original TEM system and developed a new set of instruments. These are more curved and, in addition, steerable. After extensive studies in an ex-vivo model, we developed a novel technique for transanal rectosigmoid resection and colorectal anastomosis. The technique comprises closure of the rectal lumen by purse-string suture, transection of the rectal wall distal to the closure, circumferential mobilization of rectum and mesorectal tissue in the anatomical plane from below upward, control of the inferior mesenteric vessel, removal of mobilized colorectum through the anus, and, finally, the colorectal anastomosis by either stapled or hand-sutured technique. This procedure was performed on three alcohol-glycerol preserved well-built human cadavers (M:F=2:1). The average operating time was 190 minutes. The average length of the resected specimen was 23 cm. There was no fecal contamination or injury to the resected specimen. Postprocedure laparotomy revealed adequate mesorectal resection and no inadvertent injury to other viscera. During dissection in the pelvis, as the resected rectum was pushed upward, an unobstructed "empty pelvis" situation was developed in the operating site, thus facilitating the mesorectal resection. Transanal access for colorectal surgery seems feasible. It provides a precise definition of the distal safety margin, good view of the pelvis for meticulous mesorectal resection, and reduces the abdominal wall trauma. These may enhance the outcome of colorectal resection. However, further clinical studies can only substantiate these findings.

Effect of verbal encoding and motor memory on test performance in the Rey Visual Design Learning Test

This study offers new evidence for the validity of the interpretation of the Rey Visual Design Learning Test (RVDLT) test score. The RVDLT is a design memory test that requires constructive output (drawings of memorized test items) in the recall phase. We mainly focused on response processes and tested the effect of a verbal and a motor memory strategy on test performance. Strategies were only explained and participants (12- to 15-year-olds) were stimulated to use them in a subsequent test session. In the verbal encoding condition, participants were instructed to name the test items of the RVDLT. In the copy condition, participants copied test items with an empty pen concurrent with test item presentation (rehearsal of motor sequences). Test performances were compared to a control group. No significant difference in RVDLT test score was detected between the verbal encoding group and the control group. However, the copy group scored significantly lower than the other two groups. Results are discussed in light of the validity of the test interpretation.

Validity of the Rey Visual Design Learning Test in Primary and Secondary School Children

The Rey Visual Design Learning Test (Rey, 1964, cited in Spreen & Strauss, 1991, Wilhelm, 2004) assesses immediate memory span, new learning, delayed recall and recognition for nonverbal material. Two studies are presented that focused on the construct validity of the RVDLT in primary and secondary school children. In the first study, primary school children performed the RVDLT and the Biber Figural Learning Test, as well as the WISC-R Block design Test, Boston Naming Test, and the Trailmaking Test, to assess discriminant validity. In the second study, the age range was expanded and the subtest Visual Reproductions of the Wechsler Memory Scale with a Delayed recall phase was used to assess the construct validity. A test for visual-motor integration and a test for attention, concentration, and speed of information processing were also added to complete the test battery for assessing discriminant validity. Moderate to high correlations were found between scores on the RVDLT and the tests used to assess construct validity. The correlational pattern of RVDLT scores and the scores on the discriminant tests is discussed.

Assessing Mood in Daily Life

Abstract. The repeated measurement of moods in everyday life, as is common in ambulatory monitoring, requires parsimonious scales, which may challenge the reliability of the measures. The current paper evaluates the factor structure, the reliability, and the sensitivity to change of a six-item mood scale designed for momentary assessment in daily life. We analyzed data from 187 participants who reported their current mood four times per day during seven consecutive days using a multilevel approach. The results suggest that the proposed three factors Calmness, Valence, and Energetic arousal are appropriate to assess fluctuations within persons over time. However, calmness and valence are not distinguishable at the between-person level. Furthermore, the analyses showed that two-item scales provide measures that are reliable at the different levels and highly sensitive to change.

Microbiological monitoring of laboratory mice and biocontainment in individually ventilated cages: a field study

Over recent years, the use of individually ventilated cage (IVC) rack systems in laboratory rodent facilities has increased. Since every cage in an IVC rack may be assumed to be a separate microbiological unit, comprehensive microbiological monitoring of animals kept in IVCs has become a challenging task, which may be addressed by the appropriate use of sentinel mice. Traditionally, these sentinels have been exposed to soiled bedding but more recently, the concept of exposure to exhaust air has been considered. The work reported here was aimed firstly at testing the efficiency of a sentinel-based microbiological monitoring programme under field conditions in a quarantine unit and in a multi-user unit with frequent imports of mouse colonies from various sources. Secondly, it was aimed at determining biocontainment of naturally infected mice kept in an IVC rack, which included breeding of the mice. Sentinels were exposed both to soiled bedding and to exhaust air. The mice which were used in the study carried prevalent infectious agents encountered in research animal facilities including mouse hepatitis virus (MHV), mouse parvovirus (MPV), intestinal flagellates and pinworms. Our data indicate that the sentinel-based health monitoring programme allowed rapid detection of MHV, intestinal flagellates and pinworms investigated by a combination of soiled bedding and exhaust air exposure. MHV was also detected by exposure to exhaust air only. The IVC rack used in this study provided biocontainment when infected mice were kept together with non-infected mice in separate cages in the same IVC rack.

On-line tracking of the coating of nanoscaled silica with titania nanoparticles via zeta-potential measurements

Nanoscaled spherical silica particles were directly coated with the titania nanoparticles by means of a heterogenic coagulation. Silica was prepared by the Stöber method, titania by a hydrolysis-condensation reaction of tetrapropylorthotitanate under acidic conditions. The on-line tracking of the coating process was performed by measuring the change in zeta potential during the gradual addition of a titania sol to the spherical silica particles. Silica particles of various sizes were used to determine the consumption of the titania sol in the dependence upon the particle size. The coated and uncoated particles were characterized by zeta-potential measurements, acoustic attenuation spectroscopy, dynamic light scattering, and scanning electron microscopy.