High-resolution isotope measurements resolve rapid ecohydrological dynamics at the soil-plant interface.

Plants rely primarily on rainfall infiltrating their root zones - a supply that is inherently variable, and fluctuations are predicted to increase on most of the Earth's surface. Yet, interrelationships between water availability and plant use on short timescales are difficult to quantify and remain poorly understood. To overcome previous methodological limitations, we coupled high-resolution in situ observations of stable isotopes in soil and transpiration water. We applied the approach along with Bayesian mixing modeling to track the fate of (2) H-labeled rain pulses following drought through soil and plants of deciduous tree ecosystems. We resolve how rainwater infiltrates the root zones in a nonequilibrium process and show that tree species differ in their ability to quickly acquire the newly available source. Sessile oak (Quercus petraea) adjusted root uptake to vertical water availability patterns under drought, but readjustment toward the rewetted topsoil was delayed. By contrast, European beech (Fagus sylvatica) readily utilized water from all soil depths independent of water depletion, enabling faster uptake of rainwater. Our results demonstrate that species-specific plasticity and responses to water supply fluctuations on short timescales can now be identified and must be considered to predict vegetation functional dynamics and water cycling under current and future climatic conditions.

A method for in situ monitoring of the isotope composition of tree xylem water using laser spectroscopy.

Field studies analyzing the stable isotope composition of xylem water are providing important information on ecosystem water relations. However, the capacity of stable isotopes to characterize the functioning of plants in their environment has not been fully explored because of methodological constraints on the extent and resolution at which samples could be collected and analysed. Here, we introduce an in situ method offering the potential to continuously monitor the stable isotope composition of tree xylem water via its vapour phase using a commercial laser-based isotope analyser and compact microporous probes installed into the xylem. Our technique enables efficient high-frequency measurement with intervals of only a few minutes per sample while eliminating the need for costly and cumbersome destructive collection of plant material and laboratory-based processing. We present field observations of xylem water hydrogen and oxygen isotope compositions obtained over several days including a labelled irrigation event and compare them against results from concurrent destructive sampling with cryogenic distillation and mass spectrometric analysis. The data demonstrate that temporal changes as well as spatial patterns of integration in xylem water isotope composition can be resolved through direct measurement. The new technique can therefore present a valuable tool to study the hydraulic architecture and water utilization of trees.

Weight loss surgery improves the metabolic status in an obese rat model but does not affect bladder fibrosis associated with high fat diet feeding.

BACKGROUND: Bladder dysfunction has one of the highest prevalences as a comorbidity of obesity in industrialized countries. The aetiopathogenesis of obesity-associated bladder dysfunction is still obscure, but there is growing evidence that general metabolic changes in obese patients may be in part responsible. As demonstrated recently, high fat diet (HFD) significantly alters the protein expression in the urinary bladder, activates multiple signalling pathways associated with cell survival and inflammation and ultimately provokes bladder fibrosis in an obese rat model. The study aimed to elucidate the role of matrix metalloproteases (MMPs) and their specific tissue inhibitors of metalloproteases (TIMPs) in obesity-related bladder extracellular matrix (ECM) remodelling and the effect of weight loss surgery via sleeve gastrectomy (SG) on phenotype and molecular parameters. METHODS: Twenty-four male Sprague-Dawley rats were used for (i) characterization of the HFD phenotype and (ii) evaluation of alterations following SG. Metabolic status, the degree of bladder fibrosis and tissue expression and activity of MMP2, MMP9, MMP14, TIMP1 and TIMP2 were analysed by immunohistochemistry, enzyme-linked immunosorbent assay and activity assays. Statistical differences were calculated by analysis of variance or independent Student's t-test. A P-value <0.05 was considered statistically significant. RESULTS: In HFD rats, we found significant alterations in lipid metabolism, fat mass, free fatty acid profile, insulin resistance and inflammatory markers. Voided volume was significantly decreased, and bladder showed marked fibrosis. MMPs and TIMPs were differentially regulated depending on animal status (controls, chow diet, HFD, and SG- and sham-operated animals) in both urothelium and detrusor smooth muscle. Although animal weight and most metabolic parameters were positively affected by SG, bladder fibrosis persisted. The limitations of this study were 1 month follow-up and lack of direct measurement of bladder function. CONCLUSIONS: Early diagnosis of the bladder dysfunction associated with obesity is essential to allow targeted early intervention, that is, before manifestation of potentially irreversible ECM fibrotic alterations.

Primary renal neuroblastoma metastasizing into liver and lungs with tumor thrombus extension into the right atrium.

Neuroblastomas are malignant tumors of the sympathetic nervous system. Areas of manifestation most commonly involve the abdomen, neck, thorax and pelvis. Primary renal neuroblastomas are extremely rare, only a few case reports exist worldwide, and even those are discussed controversially.We present the case of a 6-year-old girl with a renal tumor and a tumor thrombus extending into the right atrium, which radiologically appeared to be a Wilms tumor. Since the lesion did not respond to nephroblastoma-specific therapy, a biopsy from one of the liver metastases was taken, revealing the revised diagnosis of a clear cell renal cell carcinoma. Histopathology of the reference center, however, described a primary renal neuroblastoma. After adjusting the chemotherapy tumornephrectomy including the complete venous thrombus could be performed without any complications.Neuroblastoma originating from a kidney is an absolute rarity that can easily be misdiagnosed as Wilms tumor, especially, if a typical tumor thrombus with extension into the inferior vena cava is seen. Therefore neuronspecific enolase in serum as well as vanillylmandelic acid and homovanillic acid in the urine should be determined in all patients when Wilms tumor is assumed. To the best of our knowledge, this is the first published case of a primary renal neuroblastoma with a tumor thrombus extending into the right atrium.

Enhanced cellulose orientation analysis in complex model plant tissues.

The orientation distribution of cellulose microfibrils in the plant cell wall is a key parameter for understanding anisotropic plant growth and mechanical behavior. However, precisely visualizing cellulose orientation in the plant cell wall has ever been a challenge due to the small size of the cellulose microfibrils and the complex network of polymers in the plant cell wall. X-ray diffraction is one of the most frequently used methods for analyzing cellulose orientation in single cells and plant tissues, but the interpretation of the diffraction images is complex. Traditionally, circular or square cells and Gaussian orientation of the cellulose microfibrils have been assumed to elucidate cellulose orientation from the diffraction images. However, the complex tissue structures of common model plant systems such as Arabidopsis or aspen (Populus) require a more sophisticated approach. We present an evaluation procedure which takes into account the precise cell geometry and is able to deal with complex microfibril orientation distributions. The evaluation procedure reveals the entire orientation distribution of the cellulose microfibrils, reflecting different orientations within the multi-layered cell wall. By analyzing aspen wood and Arabidopsis stems we demonstrate the versatility of this method and show that simplifying assumptions on geometry and orientation distributions can lead to errors in the calculated microfibril orientation pattern. The simulation routine is intended to be used as a valuable tool for nanostructural analysis of plant cell walls and is freely available from the authors on request.

[Age-dependent visceral medicine: paediatric visceral medicine - visceral medical paediatrics - considerations on the short bowel syndrome in childhood]. / Altersabhängige Viszeralmedizin: pädiatrische Viszeralmedizin - viszeralmedizinische Pädiatrie - Überlegungen zum Kurzdarmsyndrom im Kindesalter.

There are several reasons for the possible development of a short bowel syndrome, which, however, occurs only rarely. The main causes consist of extended intestinal resections in cases of congenital anomalies (e.g., gastroschisis, intestinal atresia or dysplasia) or ischaemic lesions due to a volvulus. In addition, an intestinal stoma at a more upper segment of the GI tract can result in the functional manifestation of a short bowel syndrome. The differentiation between temporary and persisting types is essential for initiation of an adequate treatment. Loss or exclusion of organic resorption area at the inner surface of the (small) intestine can be associated with numerous pathological consequences requiring treatment. As a principle consideration from the paediatric point of view, the potential of intestinal adaptation needs to be assessed. Basic conservative treatment options are parenteral and enteral nutrition regimens, in particular, to prevent complications (such as D-lactate acidosis). The main surgical approaches are the procedures called LILT (longitudinal intestinal lengthening and tailoring) according to Bianchi and STEP (serial transverse enteroplasty). The technique to create intestinal segments of antiperistalsis has been abandoned. Because of the encouraging results of intestinal transplantation, this novel treatment option has gained greater attention over the past few years and is now also an option for paediatric patients. The limiting factor and thus major complication is the central venous catheter for long-term treatment. Catheter-related complications are still the main reason for a considerable mortality in these children.

[Bariatric surgery in extremely obese children and adolescents]. / Bariatrische Chirurgie bei extremer Adipositas im Kindes- und Jugendalter.

The management of childhood obesity is a clinical dilemma. Validated and evidence-based intervention programs are still missing for this age group, and pediatricians increasingly see children with morbid obesity and with obesity-related comorbidities. For those extremely obese patients who failed to respond to the classical therapeutic approaches, bariatric surgery is a therapeutic option. Although available data for bariatric surgery in childhood and adolescence is limited to date, significant postoperative reduction in BMI and an evident improvement of preoperatively existing metabolic and cardiovascular comorbidities and psychosocial well-being have been reported. The indication for bariatric surgery in adolescents follows strict criteria and should be proposed within an interdisciplinary team in specialized centers, including a clinical ethics committee. This review discusses the present guidelines for bariatric surgery in childhood and adolescence as well as available follow-up data for both adults and pediatric patients.

Soil gas probes for monitoring trace gas messengers of microbial activity.

Soil microbes vigorously produce and consume gases that reflect active soil biogeochemical processes. Soil gas measurements are therefore a powerful tool to monitor microbial activity. Yet, the majority of soil gases lack non-disruptive subsurface measurement methods at spatiotemporal scales relevant to microbial processes and soil structure. To address this need, we developed a soil gas sampling system that uses novel diffusive soil probes and sample transfer approaches for high-resolution sampling from discrete subsurface regions. Probe sampling requires transferring soil gas samples to above-ground gas analyzers where concentrations and isotopologues are measured. Obtaining representative soil gas samples has historically required balancing disruption to soil gas composition with measurement frequency and analyzer volume demand. These considerations have limited attempts to quantify trace gas spatial concentration gradients and heterogeneity at scales relevant to the soil microbiome. Here, we describe our new flexible diffusive probe sampling system integrated with a modified, reduced volume trace gas analyzer and demonstrate its application for subsurface monitoring of biogeochemical cycling of nitrous oxide (N2O) and its site-specific isotopologues, methane, carbon dioxide, and nitric oxide in controlled soil columns. The sampling system observed reproducible responses of soil gas concentrations to manipulations of soil nutrients and redox state, providing a new window into the microbial response to these key environmental forcings. Using site-specific N2O isotopologues as indicators of microbial processes, we constrain the dynamics of in situ microbial activity. Unlocking trace gas messengers of microbial activity will complement -omics approaches, challenge subsurface models, and improve understanding of soil heterogeneity to disentangle interactive processes in the subsurface biome.

Contrasting Community Assembly Forces Drive Microbial Structural and Potential Functional Responses to Precipitation in an Incipient Soil System.

Microbial communities in incipient soil systems serve as the only biotic force shaping landscape evolution. However, the underlying ecological forces shaping microbial community structure and function are inadequately understood. We used amplicon sequencing to determine microbial taxonomic assembly and metagenome sequencing to evaluate microbial functional assembly in incipient basaltic soil subjected to precipitation. Community composition was stratified with soil depth in the pre-precipitation samples, with surficial communities maintaining their distinct structure and diversity after precipitation, while the deeper soil samples appeared to become more uniform. The structural community assembly remained deterministic in pre- and post-precipitation periods, with homogenous selection being dominant. Metagenome analysis revealed that carbon and nitrogen functional potential was assembled stochastically. Sub-populations putatively involved in the nitrogen cycle and carbon fixation experienced counteracting assembly pressures at the deepest depths, suggesting the communities may functionally assemble to respond to short-term environmental fluctuations and impact the landscape-scale response to perturbations. We propose that contrasting assembly forces impact microbial structure and potential function in an incipient landscape; in situ landscape characteristics (here homogenous parent material) drive community structure assembly, while short-term environmental fluctuations (here precipitation) shape environmental variations that are random in the soil depth profile and drive stochastic sub-population functional dynamics.

Foetal hepatocyte transplantation in a vascularized AV-Loop transplantation model in the rat.

The use of foetal liver cells (FLC) in the context of hepatic tissue engineering might permit efficient in vitro expansion and cryopreservation in a cell bank. A prerequisite for successful application of bioartificial liver tissue is sufficient initial vascularization. In this study, we evaluated the transplantation of fibrin gel-immobilized FLC in a vascularized arterio-veno-venous (AV)-loop model. FLC were isolated from embryonic/foetal (ED 16) rat livers and were enriched by using magnetic cell sorting (MACS). After cryopreservation, FLC were labelled by pkh-26. Cells were transplanted in a fibrin matrix into a subcutaneous chamber containing a microsurgically created AV-loop in the femoral region of the recipient rat. The chambers were explanted after 14 days. Subcutaneous implants without an AV-loop and cell-free implants served as controls. Fluorescence microscopy of the constructs was used to identify pkh-26(+)- donor cells. Characterization was performed by RT-PCR and immunhistology (IH) for CK-18 and CD31. Transplantation of FLC using the AV-loop permitted a neo-tissue formation in the fibrin matrix. A high-density vascularization was observed in the AV-loop constructs as shown by CD31 IH. Viable foetal donor cells were detected which expressed CK-18. FLC can be successfully used for heterotopic transplantation. Fibrin matrix permits rapid blood vessel ingrowth from the AV-loop and supports engraftment of FLC. It is therefore an appropriate environment for hepatocyte transplantation in combination with microsurgical vascularization strategies. Transplantation of fibrin gel-immobilized FLC may be a promising approach for the development of highly vascularized in vivo tissue-engineering-based liver support systems.

Coherence and wavefront characterization of Si-111 monochromators using double-grating interferometry.

A study of the coherence and wavefront properties of a pseudo-channel-cut monochromator in comparison with a double-crystal monochromator is presented. Using a double-grating interferometer designed for the hard X-ray regime, the complex coherence factor was measured and the wavefront distortions at the sample position were analyzed. A transverse coherence length was found in the vertical direction that was a factor of two larger for the channel-cut monochromator owing to its higher mechanical stability. The wavefront distortions after different optical elements in the beam, such as monochromators and mirrors, were also quantified. This work is particularly relevant for coherent diffraction imaging experiments with synchrotron sources.

Subnanometer CdS clusters self-confined in MFI-type zeolite nanoparticles and thin films.

One-step colloidal synthesis of subnanometer CdS clusters in hydrophobic MFI-type zeolite crystals in the presence of 3-mercaptopropyl-trimethoxysilane (MPS), cadmium precursor, and tetrapropylammonium hydroxide (TPAOH) is performed. MPS is used as the bifunctional agent, as it hydrolyzes fast, cross-links with the silica framework, and provides thiol groups to anchor Cd(2+), and subsequently forms CdS clusters. The MFI crystals with the thiol groups not only function as a nanochamber for the formation of CdS but also prevent further moisture-induced agglomeration of the clusters. Direct evidence for the presence of asymmetric shaped subnanometer CdS clusters aligned in the channels of MFI crystals stabilized in suspensions and films is provided by high resolution transmission electron microscopy (HRTEM), grazing incidence X-ray diffraction (GI-XRD), and photoluminescence spectra (emission < 350 nm). The CdS clusters are stable for months in colloidal suspensions and films without any particular precaution against water. The hydrophobicity of the MFI zeolite and the presence of the organic template in the channels favor the stabilization of small CdS clusters, which are available for further applications.

[Laparoendoscopic single site cholecystectomy (LESS) in a 16-year-old girl: the way to go even in pediatric surgery?]. / Laparoendoskopische Single-Site-Cholezystektomie (LESS) bei einem 16-jährigen Mädchen: Ein Weg auch für die Kinderchirurgie?

The laparoscopic paradigm to place different ports according to ergonomic principles is presently challenged by laparoendoscopic single site surgery (LESS). Its objective is to perform a complex task with several instruments using only one access. However, this approach introduces distinct ergonomic problems and requires innovative technical solutions to allow for more complex surgical tasks. In paediatric surgery, this development has just begun. A 16-year-old girl presented with a symptomatic cholecystolithiasis. A multi-channel TriPort (Advanced Surgical Concepts) was introduced through a 20 mm umbilical incision for LESS cholecystectomy. Retraction of the gallbladder was facilitated by a straight grasper, which was inserted transabdominally. For exposition and triangulation a pre-bend dissector (5 mm, Olympus) was employed. Thus, the cystic duct and artery could be exposed, clipped (5mm) and divided. Finally, the gallbladder was dissected from its bed and extracted into a specimen bag. Operating time was 90 minutes and no intra- or postoperative complications occurred. In conclusion, a multi-channel port and angulated instruments during LESS cholecystectomy provided ergonomics close to conventional laparoscopic surgery. For smaller children though, this technology will have to be adapted to their geometry. Finally, even though LESS seems attractive, the present euphoria should not turn into scientific acceptance, until more experience is available and valid data have proven a benefit for patients of any age.

[Thoracic surgery in neonates and infants with congenital malformations]. / Thoraxchirurgie bei Neugeborenen und Säuglingen mit angeborenen Fehlbildungen.

Congenital malformations of the lung and diaphragm are a challenge in paediatric surgery. Depending on the malformation they show a broad spectrum of symptoms and a varying age at manifestation. Thus there are many diagnostic and therapeutic options, which require a good knowledge of the pathology. The treatment of these complex cases should lead to early referral to paediatric centres containing an interdisciplinary team with neonatologists, paediatric pulmonologists and cardiologists, ENT surgeons, anaesthesiologists, radiologists and paediatric surgeons. Some malformations are diagnosed prenatally and need intrauterine interventions. Decisive is the early diagnosis and treatment of these malformations. Nowadays the surgical therapy of neonates and infants with malformations of the lung and diaphragm is enriched by a number of endoscopic and endoluminal techniques, which are discussed critically in this article.

[Fetoscopic surgery as prenatal intervention for isolated congenital diaphragmatic hernia]. / Die fetoskopische Chirurgie als Möglichkeit der pränatalen Intervention bei der isolierten angeborenen Zwerchfellhernie.

Congenital diaphragmatic hernia (CDH) occurs sporadically with an incidence of 1:2,500 live births. Despite the progress in neonatal intensive care, CDH remains associated with a mortality of at least 30 % in isolated cases. The in essence surgically correctable defect of the diaphragm enables the prenatal herniation of abdominal organs into the thoracic cavity. The resulting abnormal development of the airways and pulmonary vessels causes neonatal respiratory insufficiency and persistent pulmonary hypertension. The condition can be diagnosed prenatally and the degree of pulmonary hypoplasia, which determines the postnatal course, can be measured to make an -individual prognosis. In severely affected patients, prenatal surgery may improve neonatal outcome by reversing pulmonary hypoplasia. This is currently implemented by percutaneous fetoscopic endoluminal tracheal occlusion (FETO) to trigger fetal lung growth. Although there are no maternal complications, preterm rupture of the membranes remains the major drawback of the procedure (20 % < 34 weeks). However, as compared to historical controls of a similar severity, survival as well as early neonatal morbidity are significantly improved by FETO. As a consequence, a multicentre randomised-controlled trial in fetuses with moderate hypoplasia on FETO compared to expectant management has been started ( www.totaltrial.eu). Primary outcome measure is survival without chronic lung disease (i. e., with-out bronchopulmonary dysplasia). A trial in severely affected -fetuses with survival as main outcome is currently under review by ethics committee. A standardised neonatal management enables optimal treatment and multicentre compatibility. It remains to be proven if fetoscopic surgery can maintain a solid position in the prenatal treatment of CDH to improve both mortality and morbidity of the affected children.

[Bariatric surgery in children and adolescents]. / Adipositaschirurgie bei Kindern und Jugendlichen.

Obesity in childhood and adolescents has gained epidemic proportions; in Germany 15-20 % of boys and girls are overweight, more than 6 % are known to be obese. By now, 25 % of relevant people show a pathological glucose intolerance, 4-5 % are developing type 2 diabetes mellitus (T2DM). In addition, metabolic disorders leading to hypertension and cardiac, renal or ophthalmological complications could be named as serious comorbidities. Medical and behavioural intervention as treatment for obesity in childhood remains largely ineffective: 5-10 % weight loss within 2 years rarely results in significant durable success. In adults, bariatric surgery is being used increasingly as an effective approach to achieve weight loss and to improve serious medical comorbidities, in particular T2DM. Enhancement of quality of life and explicit extension of survival are concomitant phenomenons. To date, a range of different types of bariatric procedures has been performed in adolescents, but studies evaluating and analysing preoperative data, postoperative course and follow-up in a representative number of patients younger than 18 years are still lacking. Nevertheless, current experience suggests significant weight loss and improving obesity-related medical comorbidities after bariatric surgery in adolescents too. Moreover, bariatric surgery in adolescents seems to induce less complications and a shorter hospital stay than in adults. Al-though surgical therapy for obesity in this group of patients remains an individual decision, even though explicit guidelines have been published specifying inclusion and exclusion criterias. Analysis of our own patient group and results of the study of the quality assurance "surgical treatment of morbid obesity" are appropriate tools to evaluate surgical techniques and to provide long-term follow-up.

The local microbiome after pediatric bladder augmentation: intestinal segments and the native urinary bladder host similar mucosal microbiota.

INTRODUCTION: Next-generation sequencing (NGS) techniques have provided novel insights into the microbiome of the urinary bladder (UB). In children after bladder augmentation using either ileum (ileocystoplasty, ICP) or colon (colocystoplasty, CCP), the fate of the mucosal microbiome introduced into the urinary tract remains unknown. OBJECTIVE: The aim was to compare the mucosal microbiome of the native UB vs the augmented intestinal segment (IS) using NGS. STUDY DESIGN: Twelve children after bladder augmentation (ICP n = 6, CCP n = 6) were included. Biopsies were taken during routine postoperative cystoscopy from the native UB and the IS. Specimens underwent whole-genome DNA extraction, 16S rRNA gene amplification, NGS, and Quantitative Insights Into Microbial Ecology (QIIME) data analysis. Downstream statistical data analyses were performed in Calypso. RESULTS: Patients' median age at the time of surgery was 11 years (6-17 years), and the median interval between augmentation and sampling was 7 years (4-13 years). α-Diversity (Shannon diversity index) was not significantly different between IS vs UB, ICP vs CCP, and male vs female. No general differences in the overall bacterial pattern (ß-diversity) were found between IS, UB, ICP, and CCP groups. The groups overlapped in principal coordinate analysis (PCoA) and non-metric multidimensional scaling (NMDS) analysis (Figure). Age at sampling had a statistically significant influence on ß-diversity at the genus level. Corynebacterium, Pseudoxanthomonas, Lactobacillus, Flavobacterium, and Micrococcus were the most dominating taxa detected over all samples. There was an obvious dominance of the genus Corynebacterium in the samples taken from the UB and IS in both ICP and CCP patients. Limitations of this study include the relatively small number of patients. CONCLUSION: After bladder augmentation, the native UB and augmented ISs (ICP and CCP) host similar microbiota despite their distinct differences of originating mucosal anatomy.

Efficacy of laparoscopic sleeve gastrectomy (LSG) as a stand-alone technique for children with morbid obesity.

BACKGROUND: Laparoscopic sleeve gastrectomy (LSG) is basically unknown as a stand-alone technique for bariatric surgery in children and adolescents. It may be advantageous for this age group though, since it requires neither foreign body placement nor life-long malabsorption. We present the first report about the efficacy of LSG in a small pediatric series. METHODS: All patients (n = 4, female) had been in a multi-modal weight loss program for several years without long-term success. At referral, the mean age was 14.5 years (range 8-17), mean body mass index (BMI in kg/m(2)) was 48.4 (range 40.6-56.3). All suffered from various features of a metabolic-vascular syndrome like diabetes, dislipidemia, cholecystolithiasis, arterial hypertension. The 8-year-old girl was diagnosed Prader-Willi Syndrome at the age of 2. The decision for bariatric surgery was taken unanimously by the parents, patient, and the obesity team. LSG was performed in a five-trocar technique. With a gastroscope (size 40-F) protecting the lesser curvature, the stomach was resected from the proximal antrum to the angle of His using an ENDO-GIA stapler. The stapler line was secured by a continuous suture 3-0 vicryl. RESULTS: There were no intra- or postoperative complications. Contrast studies confirmed a J-like gastric remnant (mean volume 76 ml) and ruled out leaks in all cases. After a mean follow-up time of 12 months (range 6-19 months), all the patients had reduced weight (mean BMI to 37.2). The girl with the longest postoperative period went from 121 to 83 kg (BMI from 40.6 to 28.4). Laboratory studies ruled out malnutrition or vitamin deficiency. Monitoring of metabolic parameters showed gradual improvement or even resolution for most features. CONCLUSION: At a 1-year follow-up, LSG proved a safe and effective option for bariatric surgery in children, achieving moderate weight loss and improvement of comorbidities. Thus, it may be considered as stand-alone technique. Long-term studies however must compare these results with time-tested procedures like gastric banding and Roux-en-Y gastric bypass.

Long gap esophageal atresia and arterial circle of Willis variant leading to ischemic stroke during gastric transposition.

In children, strokes occur with a frequency of 2 to 13 per 100,000. Risk factors include hematological, embolic and anatomical anomalies. But often the exact cause of strokes in pediatric patients remains unclear. We report here on a patient with long gap esophageal atresia, who suffered an ischemic stroke during gastric transposition. Postoperative assessment revealed a cerebral vascular variant of the circle of Willis. Follow-up clinical controls showed a favorable course. Today, at the age of 14 months, almost no neurological deficits are evident. To the best of our knowledge, no description of vascular cerebral complications combined with esophageal atresia can be found in the literature.

Laparoscopic sleeve gastrectomy achieves substantial weight loss in an adolescent girl with morbid obesity.

BACKGROUND: The European guidelines for bariatric surgery clearly define criteria for operating children with morbid obesity. However the appropriate technique for this age-group has not been identified yet. So far gastric banding and Roux-Y bypass represent the standards, but they demand life-long tolerance of either an artificial device or significant malabsorption. Although laparoscopic sleeve gastrectomy (LSG) demands neither, it has not been advocated for this age-group as a stand-alone technique. We report the outcome and the rationale for this approach in a 16-year-old girl with morbid obesity. MATERIAL AND METHOD: The patient had been in an intensive weight loss programme for several years, but within the last 12 months her body weight had increased again dramatically. At referral she presented with a body mass index (BMI) of 43.1 kg/m(2) (height 169 cm, preoperative weight 121 kg) and suffered from co-morbidities as features of a developing metabolic-vascular syndrome such as dyslipidemia and arterial hypertension. Our obesity team and her parents opted for surgery at that time. The patient underwent LSG with a 5-trocar technique. With a gastroscope protecting the lesser curvature, the stomach was resected from the antrum to the fundus using an EndoGIA stapler. The operative time was 95 minutes, there were no perioperative complications and the patient was extubated immediately. An upper GI contrast study on postoperative day 4 showed a tubular gastric remnant with a volume of about 200 ml. The patient's diet was advanced as tolerated to full oral intake, and she was followed-up regularly in our special obesity outpatient clinic. After 12 months she had lost 36 kg (BMI 29 kg/m(2)) and enjoyed sports and activities with friends again. Laboratory studies ruled out malnutrition or vitamin deficiency. CONCLUSION: LSG is a safe and effective option for bariatric surgery in obese adolescents. It can be offered as a stand-alone restrictive operation and could be extended to a malabsorptive procedure at any time. However longer follow-up is required before universally recommending this procedure.