Obesity and diabetes mellitus are associated with SARS-CoV-2 outcomes without influencing signature genes of extrapulmonary immune compartments at the RNA level

The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) which is responsible for eliciting Coronavirus disease 2019 (COVID-19) still challenges healthcare services worldwide. While many patients only suffer from mild symptoms, patients with some pre-existing medical conditions are at a higher risk for a detrimental course of disease. However, the underlying mechanisms determining disease course are only partially understood. One key factor influencing disease severity is described to be immune-mediated. In this report, we describe a post-mortem analysis of 45 individuals who died from SARS-CoV-2 infection. We could show that although sociodemographic factors and premedical conditions such as obesity and diabetes mellitus reduced survival time in our cohort, they were not associated with changes in the expression of immune-related signature genes at the RNA level in the blood, the gut, or the liver between these different groups. Our data indicate that obesity and diabetes mellitus influence SARS-CoV-2-related mortality, without influencing the extrapulmonary gene expression of immunity-related signature genes at the RNA level.

The Effect of Non-Alcoholic Fatty Liver Disease on Weight Loss and Resolution of Obesity-Related Disorders After Bariatric Surgery

BACKGROUND

Patients undergoing bariatric surgery have a high incidence of non-alcoholic fatty liver disease (NAFLD). However, the effect of NAFLD or non-alcoholic steatohepatitis (NASH) on the weight loss and resolution of obesity-related disorders is a matter of debate.

METHODS

In this study, we compare the long-term outcomes after bariatric with the presence of NAFLD in the liver biopsy at the time of surgery.

RESULTS

The follow-up was available for 226 out of 288 patients. The mean follow-up time was 24.9 (± 13.6) months. The baseline histology showed that 112 patients (38.9%) had no NASH, 70 (24.3%) were borderline, and 106 (36.8%) had NASH. At follow-up, the mean BMI dropped from (52 ± 10.2) to (36.6 ± 8) kg/m 2. Excess weight loss (EWL) was similar in all NAFLD groups. Type 2 diabetes mellitus dropped from 35.7 to 11.4%, hypertension from 65.6 to 36.7%, hyperlipidemia from 62.3 to 33%, and obstructive sleep apnea from 37.5 to 14.9%. Only hyperlipidemia was significantly associated with NASH compared to the groups with no NASH or borderline NASH (p value = 0.002 and p value = 0.04, respectively) during the first two years of follow-up.

CONCLUSION

The beneficial effects of bariatric surgery are evident across all patients with NAFLD. Patients with NASH have comparable outcomes regarding weight loss and resolution of obesity-related comorbidities.

Intestinal IL-1β Plays a Role in Protecting against SARS-CoV-2 Infection

The intestine is constantly balancing the maintenance of a homeostatic microbiome and the protection of the host against pathogens such as viruses. Many cytokines mediate protective inflammatory responses in the intestine, among them IL-1β. IL-1β is a proinflammatory cytokine typically activated upon specific danger signals sensed by the inflammasome. SARS-CoV-2 is capable of infecting multiple organs, including the intestinal tract. Severe cases of COVID-19 were shown to be associated with a dysregulated immune response, and blocking of proinflammatory pathways was demonstrated to improve patient survival. Indeed, anakinra, an Ab against the receptor of IL-1β, has recently been approved to treat patients with severe COVID-19. However, the role of IL-1β during intestinal SARS-CoV-2 infection has not yet been investigated. Here, we analyzed postmortem intestinal and blood samples from patients who died of COVID-19. We demonstrated that high levels of intestinal IL-1β were associated with longer survival time and lower intestinal SARS-CoV-2 RNA loads. Concurrently, type I IFN expression positively correlated with IL-1β levels in the intestine. Using human intestinal organoids, we showed that autocrine IL-1β sustains RNA expression of IFN type I by the intestinal epithelial layer. These results outline a previously unrecognized key role of intestinal IL-1β during SARS-CoV-2 infection.

Differences in DNA methylation of HAMP in blood cells predicts the development of type 2 diabetes

OBJECTIVES

Better disease management can be achieved with earlier detection through robust, sensitive, and easily accessible biomarkers. The aim of the current study was to identify novel epigenetic biomarkers determining the risk of type 2 diabetes (T2D).

METHODS

Livers of 10-week-old female New Zealand Obese (NZO) mice, slightly differing in their degree of hyperglycemia and liver fat content and thereby in their diabetes susceptibility were used for expression and methylation profiling. We screened for differences in hepatic expression and DNA methylation in diabetes-prone and -resistant mice, and verified a candidate (HAMP) in human livers and blood cells. Hamp expression was manipulated in primary hepatocytes and insulin-stimulated pAKT was detected. Luciferase reporter assays were conducted in a murine liver cell line to test the impact of DNA methylation on promoter activity.

RESULTS

In livers of NZO mice, the overlap of methylome and transcriptome analyses revealed a potential transcriptional dysregulation of 12 hepatokines. The strongest effect with a 52% decreased expression in livers of diabetes-prone mice was detected for the Hamp gene, mediated by elevated DNA methylation of two CpG sites located in the promoter. Hamp encodes the iron-regulatory hormone hepcidin, which had a lower abundance in the livers of mice prone to developing diabetes. Suppression of Hamp reduces the levels of pAKT in insulin-treated hepatocytes. In liver biopsies of obese insulin-resistant women, HAMP expression was significantly downregulated along with increased DNA methylation of a homologous CpG site. In blood cells of incident T2D cases from the prospective EPIC-Potsdam cohort, higher DNA methylation of two CpG sites was related to increased risk of incident diabetes.

CONCLUSIONS

We identified epigenetic changes in the HAMP gene which may be used as an early marker preceding T2D.

Auditory neural correlates and neuroergonomics of driving assistance in a simulated virtual environment

Objective.Driver assistance systems play an increasingly important role in modern vehicles. In the current level of technology, the driver must continuously supervise the driving and intervene whenever necessary when using driving assistance systems. The driver's attentiveness plays an important role in this human-machine interaction. Our aim was to design a simplistic technical framework for studying neural correlates of driving situations in a functional magnetic resonance imaging (fMRI) setting. In this work we assessed the feasibility of our proposed platform.Methods.We proposed a virtual environment (VE) simulation of driver assistance as a framework to investigate brain states related to partially automated driving. We focused on the processing of auditory signals during different driving scenarios as they have been shown to be advantageous as warning stimuli in driving situations. This provided the necessary groundwork to study brain auditory attentional networks under varying environmental demands in an fMRI setting. To this end, we conducted a study with 20 healthy participants to assess the feasibility of the VE simulation.Results.We demonstrated that the proposed VE can elicit driving related brain activation patterns. Relevant driving events evoked, in particular, responses in the bilateral auditory, sensory-motor, visual and insular cortices, which are related to perceptual and behavioral processes during driving assistance. Conceivably, attentional mechanisms increased somatosensory integration and reduced interoception, which are relevant for requesting interactions during partially automated driving.Significance.In modern vehicles, driver assistance technologies are playing an increasingly prevalent role. It is important to study the interaction between these systems and drivers' attentional responses to aid in future optimizations of the assistance systems. The proposed VE provides a foundational first step in this endeavor. Such simulated VEs provide a safe setting for experimentation with driving behaviors in a semi-naturalistic environment.

Socioeconomic Deprivation Is Not Associated with Outcomes after Esophagectomy at a German High-Volume Center

In Germany, socioeconomically deprived citizens more often develop esophageal carcinoma, since typical risk factors follow the social gradient. Therefore, we hypothesized that socioeconomic deprivation might also be associated with advanced tumor stages and comorbidities at the time of surgery. As a consequence, socioeconomic deprivation may be related to postoperative complications and reduced overall survival. Therefore, 310 patients who had undergone esophagectomy for cancer in curative intent between 2012 and 2020 at the University Medical Center Hamburg-Eppendorf (UKE) were included in this study. Socioeconomic status (SES) was estimated using the purchasing power of patients' postal codes as a surrogate parameter. No association was found between SES and tumor stage or comorbidities at the time of surgery. Moreover, SES was neither associated with postoperative complications nor overall survival. In conclusion, socioeconomic inequalities of patients treated at a high-volume center do not affect treatment outcomes.

TNFα aggravates detrimental effects of SARS-CoV-2 infection in the liver

Coronavirus disease 2019 (COVID-19) is caused by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). This virus does not only lead to pulmonary infection but can also infect other organs such as the gut, the kidney, or the liver. Recent studies confirmed that severe cases of COVID-19 are often associated with liver damage and liver failure, as well as the systemic upregulation of pro-inflammatory cytokines such as tumor necrosis factor-alpha (TNFα). However, the impact these immune mediators in the liver have on patient survival during SARS-CoV-2 infection is currently unknown. Here, by performing a post-mortem analysis of 45 patients that died from a SARS-CoV-2 infection, we find that an increased expression of TNFA in the liver is associated with elevated mortality. Using publicly available single-cell sequencing datasets, we determined that Kupffer cells and monocytes are the main sources of this TNFα production. Further analysis revealed that TNFα signaling led to the upregulation of pro-inflammatory genes that are associated with an unfavorable outcome. Moreover, high levels of TNFA in the liver were associated with lower levels of interferon alpha and interferon beta. Thus, TNFα signaling in the infected SARS-CoV-2 liver correlates with reduced interferon levels and overall survival time.

Fatty Acid Induced Hypermethylation in the Slc2a4 Gene in Visceral Adipose Tissue Is Associated to Insulin-Resistance and Obesity

De novo lipogenesis (DNL) in visceral adipose tissue (VAT) is associated with systemic insulin sensitivity. DNL in VAT is regulated through ChREBP activity and glucose uptake through Glut4 (encoded by Slc2a4). Slc2a4 expression, ChREBP activity, and DNL are decreased in obesity, the underlying cause however remains unidentified. We hypothesize that increased DNA methylation in an enhancer region of Slc2a4 decreases Slc2a4 expression in obesity and insulin resistance. We found that SLC2A4 expression in VAT of morbidly obese subjects with high HbA1c (>6.5%, n = 35) is decreased, whereas DNA methylation is concomitantly increased compared to morbidly obese subjects with low HbA1c (≤6.5%, n = 65). In diet-induced obese (DIO) mice, DNA methylation of Slc2a4 persistently increases with the onset of obesity and insulin resistance, while gene expression progressively decreases. The regulatory impact of DNA methylation in the investigated enhancer region on SLC2A4 gene expression was validated with a reporter gene assay. Additionally, treatment of 3T3 pre-adipocytes with palmitate/oleate during differentiation decreased DNA methylation and increased Slc2a4 expression. These findings highlight a potential regulation of Slc2a4 by DNA methylation in VAT, which is induced by fatty acids and may play a role in the progression of obesity and insulin resistance in humans.

Multicytokine-producing CD4+ T cells characterize the livers of patients with NASH

A role of CD4+ T cells during the progression from nonalcoholic fatty liver disease (NAFLD) to nonalcoholic steatohepatitis (NASH) has been suggested, but which polarization state of these cells characterizes this progression and the development of fibrosis remain unclear. In addition, a gut-liver axis has been suggested to play a role in NASH, but the role of CD4+ T cells in this axis has just begun to be investigated. Combining single-cell RNA sequencing and multiple-parameter flow cytometry, we provide the first cell atlas to our knowledge focused on liver-infiltrating CD4+ T cells in patients with NAFLD and NASH, showing that NASH is characterized by a population of multicytokine-producing CD4+ T cells. Among these cells, only those with a Th17 polarization state were enriched in patients with advanced fibrosis. In parallel, we observed that Bacteroides appeared to be enriched in the intestine of NASH patients and to correlate with the frequency of multicytokine-producing CD4+ T cells. In short, we deliver a CD4+ T cell atlas of NAFLD and NASH, providing the rationale to target CD4+ T cells with a Th17 polarization state to block fibrosis development. Finally, our data offer an early indication to test whether multicytokine-producing CD4+ T cells are part of the gut-liver axis characterizing NASH.

Fatty acid-binding protein-4 (FABP4) and matrix metalloproteinase-9 (MMP9) as predictive values for nonalcoholic steatohepatitis (NASH)

BACKGROUND

Nonalcoholic fatty liver disease (NAFLD), especially nonalcoholic steatohepatitis (NASH) increases the risk for liver cirrhosis. Noninvasive tests for NAFLD/NASH exist, but they are unreliable and thus liver biopsy remains the standard for diagnosis and new noninvasive diagnostic approaches are of great interest. The aim of this study was to test whether the serum levels of fatty acid-binding protein-4 (FABP4) and matrix metalloproteinase-9 (MMP9) could be used as a diagnostic tool for NASH.

METHODS

Patients who underwent bariatric surgery and simultaneous liver biopsy were identified. Biopsies were assigned a NAFLD activity score (NAS). MMP9- and FABP4- Enzyme-linked Immunosorbent Assays (ELISAs) on serum samples were performed. The serum levels of FABP4/MMP9 were compared and different models to predict NASH were developed.

RESULTS

A total of 84 patients were included, 28 patients (33.3%) were diagnosed with NASH. Higher concentrations of MMP9 in NASH patients (p < 0.01) were detected. FABP4 concentrations were not significantly increased. A moderate correlation between the NAS and MMP9 concentrations (r = 0.32, P < 0.01) was observed. The neural network model fit best with the dataset, with an area under the curve (AUC) of 83% and an accuracy of 88%.

CONCLUSION

Serum MMP9 levels are increased in patients with NASH and should routinely be measured in patients with obesity, but further investigations are needed to improve noninvasive NASH diagnosis.

Full endoscopic anterior intrapelvic plate osteosynthesis: a cadaveric feasibility study

In this investigation, it was assumed that it must be possible to visualize the intrapelvic aspect as accustomed by pelvic surgeons using the anterior intrapelvic (modified Stoppa) approach. Moreover, it was hypothesized, that plate mountings will not only be possible for the symphysis but also at the supra- and infrapectineal aspect as well as to the posterior column. Ten anonymized cadaveric specimens were included in this study. A standard laparoscopic totally extraperitoneal (TEP) approach was used. A total of 10 landmarks were defined that are usually within reach in the open anterior intrapelvic (AIP) approach. Moreover, five different plate mountings were tested. The locations were chosen in accordance with the indication spectrum suitable for open surgery through the traditional AIP approach. It was possible to gain intrapelvic visibility in seven of ten cases. In all of those seven cases, it was technically possible to place plates to the symphysis, superior pubic ramus, as well as longer anterior column plates up to the aspect posterior of the acetabulum. In the last four of the seven cases, it was possible to mount plates to the infrapectineal aspect as well as the posterior column, too. The team, previously trained in arthroscopic surgical techniques as well as pelvic trauma surgery, observed a steep learning curve. This investigation demonstrated, that endoscopic anterior intrapelvic plate osteosynthesis was feasible in the majority of the cases in a series of ten cadaveric models. New instruments will be needed such as extra-long rasp elevators, ball-spikes as well as devices to hold and position plates and extra-long self-holding screwdrivers. With these, endoscopic pelvic surgery will likely be a realistic option for selected pelvic trauma cases in the future.

Low-Grade Hepatic Steatosis Is Associated with Long-term Remission of Type 2 Diabetes Independent of Type of Bariatric-Metabolic Surgery

BACKGROUND

Bariatric-metabolic surgery (BS) decreases the grade of steatosis, hepatic inflammation, and fibrosis in patients with severe obesity and non-alcoholic fatty liver disease (NAFLD). Mechanisms include substantial weight loss, but also simultaneous effects on glucose homeostasis. Therefore, we aimed to investigate the association between NAFLD and remission of type 2 diabetes (T2D) up to 8 years following different types of BS.

METHODS

In a retrospective cohort study including 107 patients with obesity and T2D at baseline, the association between biopsy-proven NAFLD defined as steatosis in > 5% of hepatocytes at the time of surgery and T2D remission up to 8 years following different surgical procedures was investigated. Univariate regression analysis was used to examine the association between NAFLD and remission of T2D.

RESULTS

Long-term remission of T2D was present in 56% of patients (n = 60). The presence of low-grade liver steatosis (grade 1) was associated with remission of T2D. Patients with a liver steatosis score ≥ 2 showed higher HbA1c levels at baseline. There were no significant differences in preoperative presence of lobular inflammation, hepatocyte ballooning, or fibrosis between patients who achieved T2D remission compared with those with no remission. Type of surgery did not affect remission of T2D.

CONCLUSION

Our results suggest that the presence of low-grade liver steatosis is associated with remission of T2D following sleeve gastrectomy (SG) and Roux-en-Y gastric bypass (RYGB). Therefore, BS should be considered at an early NAFLD stage in patients with T2D.

A Critical Role of the IL-22-IL-22 Binding Protein Axis in Hepatocellular Carcinoma

Hepatocellular carcinoma (HCC) ranks among the five most common cancer entities worldwide and leads to hundred-thousands of deaths every year. Despite some groundbreaking therapeutical revelations during the last years, the overall prognosis remains poor. Although the immune system fights malignant transformations with a robust anti-tumor response, certain immune mediators have also been shown to promote cancer development. For example, interleukin (IL)-22 has been associated with HCC progression and worsened prognosis in multiple studies. However, the underlying mechanisms of the pathological role of IL-22-signaling as well as the role of its natural antagonist IL-22 binding protein (IL-22BP) in HCC remain elusive. Here, we corroborate the pathogenic role of IL-22 in HCC by taking advantage of two mouse models. Moreover, we observed a protective role of IL-22BP during liver carcinogenesis. While IL-22 was mainly produced by CD4⁺ T cells in HCC, IL-22BP was abundantly expressed by neutrophils during liver carcinogenesis. Hepatocytes could be identified as a major target of this pathological IL-22-signaling. Moreover, abrogation of IL-22 signaling in hepatocytes in IL22ra1^flox/flox × Alb^Cre+ mice reduced STEAP4 expression-a known oncogene-in HCC in vivo. Likewise, STEAP4 expression correlated with IL22 levels in human HCC samples, but not in healthy liver specimens. In conclusion, these data encourage the development of therapeutical approaches that target the IL-22-IL-22BP axis in HCC.

Spannungsfeld endoskopische Resektionsverfahren bei GEP-NET // Endoscopic resection for GEP-NET

Neuroendokrine Tumoren des Verdauungstraktes (GEP-NET) sind eine seltene Tumorentität, die häufig als Zufallsbefund diagnostiziert werden. Ein großer Teil dieser Zufallsdiagnosen wird im Rahmen einer endoskopischen Untersuchung gestellt. Während die vollständige Entfernung des Tumors im Sinne einer kurativen chirurgischen Resektion nach onkologischen Kriterien das Standardvorgehen für lokalisierte Tumorerkrankungen ist, kann bei kleinen Tumoren ohne Hinweis und Risiko für eine lymphogene Metastasierung eine endoskopische Abtragung in gleicher Intention erfolgen. Während dies für Magen-, Duodenum- und Rektum-NET der Standard ist, sollten NET des Jejunums und Ileums aufgrund der hohen Metastasierungsrate trotz geringer Tumorgröße regelhaft nicht endoskopisch angegangen werden. Die Grenze für eine endoskopische Resektion ergibt sich sowohl durch die technische Machbarkeit im Sinne des Erreichens einer R0-Resektion, der erwarteten Komplikationen im Sinne von Blutung und Perforationen als auch durch das vermutete Risiko für eine lymphogene Metastasierung. Generell wird eine endoskopische Resektion bei Befunden < 1 cm regelhaft empfohlen, da sowohl die gute technische Machbarkeit als auch das geringe Metastasierungsrisiko für eine endoskopische Resektion sprechen. Bei allen Befunden über 2 cm Größe sind sowohl die technischen Erfolgsaussichten so niedrig als auch das Metastasierungsrisiko so hoch, dass in dieser Situation regelhaft ein chirurgisches Vorgehen erfolgen sollte. Es bleibt somit ein Graubereich bei der Tumorgröße zwischen 1 und 2 cm, wo sowohl endoskopische, aber auch chirurgische Resektionsverfahren sinnvoll eingesetzt werden können. Zunehmend kommen auch gemeinsame Eingriffe im Sinne eines endoskopisch-laparoskopischen Rendezvous-Verfahrens zum Einsatz – insbesondere im Duodenum bieten sich diese Eingriffe an, um eine minimale Resektion mit größtmöglicher R0-Erfolgsrate und niedriger Perforationsrate zu erreichen.

Metabolic Syndrome Is Associated with Impaired Survival after Surgery for Pancreatic Neuroendocrine Tumors

INTRODUCTION

Pancreatic neuroendocrine tumors (pNETs) are a heterogeneous group of neoplasms. Surgery is the only curative treatment option. However, our understanding of predictors of survival after surgery remains incomplete. The aim of the study was to evaluate metabolic syndrome (MetS) as a prognostic factor in pNET.

METHODS

In a retrospective single-center cohort study, we examined the influence of MetS in 120 patients with curative intended resection of pNETs on overall survival (OS), recurrence-free survival, and outcome after recurrence.

RESULTS

MetS was present in 32 patients (26.6%). Patients with MetS had an impaired OS after curative intended surgery compared to patients without MetS (median OS 72 months [95% CI 13.3-130.7] vs. not reached, p < 0.001). The shortest survival was observed in patients with MetS in the presence of oligometastatic disease at time of surgery. In a multivariable Cox regression analysis, MetS was identified as an independent risk factor for mortality (hazard ratio [HR] = 4.54, 95% CI [1.88-11.00], p = 0.01). In our dataset, MetS was not associated with tumor recurrence or recurrence-free survival. Nevertheless, in patients with recurrence, MetS was associated with shorter time to recurrence (median 3.4 months, 95% CI [2.48-4.24], vs. 20.1 months, 95% CI [10.8-29.49], p < 0.001), and poor outcome (HR = 5.03, 95% CI [1.25-20.20], p = 0.01).

CONCLUSIONS

We identified MetS as a negative prognostic factor after curative intended surgery for pNET. In particular, patients with oligometastatic disease might not benefit from extensive surgery in the presence of MetS. Furthermore, MetS had a strong impact on survival after recurrence.

Higher Socioeconomic Status is Associated with Improved Outcomes After Obesity Surgery Among Women in Germany

Background

Low socioeconomic status (SES) is associated with an increased prevalence of obesity. It is unknown whether SES influences the outcome after bariatric surgery in Germany. Therefore, the aim of our study was to investigate whether the SES is linked with an inferior outcome after bariatric surgery.

Methods

We included all patients who underwent bariatric surgery in our university hospital from 2012–2014. Net income was estimated by matching the zip codes of patient residency with the region-specific purchasing power index. We analyzed the relationship between SES, weight loss and remission of comorbidities.

Results

We included 559 patients in this study and detected a mean 5-year percentage excess weight loss (%EWL) of 52.3%. We detected a significantly lower initial body mass index (BMI) and weight in patients with a higher income. One year after surgery, we did not find a significant difference. Further analysis revealed that only women with a higher income had a significantly lower BMI and weight 3 and 5 years after surgery.

Conclusions

Bariatric surgery is beneficial for all patients regardless of income. Furthermore, we demonstrated that women with high SES have a better outcome after bariatric surgery.

Size-Dependent Electroluminescence and Current-Voltage Measurements of Blue InGaN/GaN µLEDs down to the Submicron Scale

Besides high-power light-emitting diodes (LEDs) with dimensions in the range of mm, micro-LEDs (μLEDs) are increasingly gaining interest today, motivated by the future applications of μLEDs in augmented reality displays or for nanometrology and sensor technology. A key aspect of this miniaturization is the influence of the structure size on the electrical and optical properties of μLEDs. Thus, in this article, investigations of the size dependence of the electro-optical properties of μLEDs, with diameters in the range of 20 to 0.65 μm, by current-voltage and electroluminescence measurements are described. The measurements indicated that with decreasing size leakage currents in the forward direction decrease. To take advantage of these benefits, the surface has to be treated properly, as otherwise sidewall damages induced by dry etching will impair the optical properties. A possible countermeasure is surface treatment with a potassium hydroxide based solution that can reduce such defects.

[The paraplegic patient-Characteristics of diagnostics and treatment in visceral surgery]

BACKGROUND

Patients with paraplegia develop syndrome-specific complications relevant to visceral surgery, which occur in the context of the acute spinal shock or as a consequence of the progressive neurogenic bowel dysfunction (NBD) with the formation of an elongated colon and/or megacolon. Moreover, acute abdominal emergencies, such as acute appendicitis, cholecystitis, diverticulitis and ileus images, pose particular challenges for the clinician when the clinical signs are atypical or even absent. The expansion of indications for obesity surgery to include patients with a paraplegic syndrome, whose independence and quality of life can be impaired due to the restricted mobility, especially by obesity, is becoming increasingly more important.

OBJECTIVE

This article provides an overview of the special requirements and aspects in the treatment of this special patient collective and to show the evidence of paraplegia-specific visceral surgery treatment.

MATERIAL AND METHODS

Targeted literature search in Medline and Cochrane library (German and English, 1985-2020).

RESULTS AND CONCLUSION

The clinical treatment of paraplegic patients requires in-depth knowledge of the pathophysiological changes at the different height of the paraplegia (upper versus lower motor neuron) and the phase of the disease (spinal shock versus long-term course). Missing or atypical clinical symptoms of acute diseases delay a quick diagnosis and make early diagnosis essential. The evidence for surgical treatment of the acute and chronic consequences of NBD is based on small retrospective series and case reports, as is that for special indications such as obesity surgery.

Performance of non-invasive fibrosis scores in non-alcoholic fatty liver disease with and without morbid obesity

BACKGROUND

Non-invasive scores, such as the non-alcoholic fatty liver disease (NAFLD) Fibrosis Score (NFS), are increasingly used for liver fibrosis assessment in patients with NAFLD. The aim of this study was to assess the applicability and reliability of non-invasive fibrosis scores in NAFLD patients with and without morbid obesity.

METHODS

Three hundred sixty-eight patients with biopsy-proven NAFLD identified between January 2012 and December 2015 were studied; 225 with morbid obesity (biopsy obtained during bariatric surgery) and 143 patients without (termed as "conventional").

RESULTS

Median age was 47 years, 57% were female. Median body mass index (BMI) was 42.9 kg/m² with significant differences between our conventional and morbidly obese patients (BMI 29.0 vs. 50.8 kg/m², p < 0.001). Overall, 42% displayed mild/moderate and 16% advanced liver fibrosis (stage III/IV). All tested scores were significantly linked to fibrosis stage (p < 0.001 for all). FIB-4 (AUROC 0.904), APRI (AUROC 0.848), and NFS (AUROC 0.750) were identified as potent predictors of advanced fibrosis, although NFS overestimated fibrosis stage in morbid obesity. Limiting BMI to a maximum of 40 kg/m² improved NFS' overall performance (AUROC 0.838). FIB-4 > 1.0 indicated high probability of advanced fibrosis (OR = 29.1). FIB-4 predicted advanced fibrosis independently from age, sex, BMI, and presence of morbid obesity.

CONCLUSIONS

Our data suggest that FIB-4 score is an accurate predictor of advanced fibrosis in NAFLD throughout all BMI stages. Without adjustment, NFS tends to overestimate fibrosis in morbidly obese NAFLD patients. This problem may be solved by implementation of an upper BMI limit (for NFS) or adjustment of diagnostic thresholds.

Knowing What's Coming: Unpredictable Motion Causes More Motion Sickness

OBJECTIVE

This study explores the role of anticipation in motion sickness. We compared three conditions varying in motion predictability and assessed the effect of anticipation on subsequent illness ratings using a within-subjects design.

BACKGROUND

Anticipation is thought to play a role in motion sickness by reducing the discrepancy between sensed and expected sensory information. However, both the exact role and potential magnitude of anticipation on motion sickness are unknown.

METHOD

Participants (N = 17) were exposed to three 15-min conditions consisting of repeated fore-aft motion on a sled on a 40-m rail (1) at constant intervals and consistent motion direction, (2) at constant intervals but varied motion direction, and (3) at varied intervals but consistent motion direction. Conditions were otherwise identical in motion intensity and displacement, as they were composed of the same repetitions of identical blocks of motion. Illness ratings were recorded at 1-min intervals using an 11-point motion sickness scale.

RESULTS

Average illness ratings after exposure were significantly lower for the predictable condition, compared with both the directionally unpredictable condition and the temporally unpredictable condition.

CONCLUSION

Unpredictable motion is significantly more provocative compared with predictable motion. Findings suggest motion sickness results from a discrepancy between sensed and expected motion, rather than from unpreparedness to motion.

APPLICATION

This study underlines the importance of an individual's anticipation to motion in motion sickness. Furthermore, this knowledge could be used in domains such as that of autonomous vehicles to reduce carsickness.

Multi-layered epigenetic regulation of IRS2 expression in the liver of obese individuals with type 2 diabetes

AIMS/HYPOTHESIS

IRS2 is an important molecular switch that mediates insulin signalling in the liver. IRS2 dysregulation is responsible for the phenomenon of selective insulin resistance that is observed in type 2 diabetes. We hypothesise that epigenetic mechanisms are involved in the regulation of IRS2 in the liver of obese and type 2 diabetic individuals.

METHODS

DNA methylation of seven CpG sites was studied by bisulphite pyrosequencing and mRNA and microRNA (miRNA) expression was assessed by quantitative real-time PCR in liver biopsies of 50 obese non-diabetic and 31 obese type 2 diabetic participants, in a cross-sectional setting. Methylation-sensitive luciferase assays and electrophoretic mobility shift assays were performed. Furthermore, HepG2 cells were treated with insulin and high glucose concentrations to induce miRNA expression and IRS2 downregulation.

RESULTS

We found a significant downregulation of IRS2 expression in the liver of obese individuals with type 2 diabetes (0.84 ± 0.08-fold change; p = 0.0833; adjusted p value [p_a] = 0.0417; n = 31) in comparison with non-diabetic obese participants (n = 50). This downregulation correlated with hepatic IRS2 DNA methylation at CpG5. Additionally, CpG6, which is located in intron 1 of IRS2, was hypomethylated in type 2 diabetes; this site spans the sterol regulatory element binding transcription factor 1 (SREBF1) recognition motif, which likely acts as transcriptional repressor. The adjacent polymorphism rs4547213 (G>A) was significantly associated with DNA methylation at a specificity-protein-1 (SP1) binding site (CpG3). Moreover, DNA methylation of cg25924746, a CpG site located in the shore region of the IRS2 promoter-associated CpG island, was increased in the liver of individuals with type 2 diabetes, as compared with those without diabetes. A second epigenetic mechanism, upregulation of hepatic miRNA hsa-let-7e-5p (let-7e-5p) in obese individuals with type 2 diabetes (n = 29) vs non-diabetic obese individuals (n = 49) (1.2 ± 0.08-fold change; p = 0.0332; p_a = 0.0450), is likely to act synergistically with altered IRS2 DNA methylation to decrease IRS2 expression. Mechanistic in vitro experiments demonstrated an acute upregulation of let-7e-5p expression and simultaneous IRS2 downregulation in a liver (HepG2) cell line upon hyperinsulinaemic and hyperglycaemic conditions.

CONCLUSIONS/INTERPRETATION

Our study highlights a new multi-layered epigenetic network that could be involved in subtle dysregulation of IRS2 in the liver of individuals with type 2 diabetes. This might lead to fine-tuning of IRS2 expression and is likely to be supplementary to the already known factors regulating IRS2 expression. Thereby, our findings could support the discovery of new diagnostic and therapeutic strategies for type 2 diabetes. Graphical abstract.

The value of CT imaging and CRP quotient for detection of postbariatric complications

Background

The diagnosis of major complications seems to be more challenging in obese patients. We aimed to show the relevance of routinely assessed clinical and paraclinical parameters as well as the relevance of CT scans in the diagnosis of major complications after bariatric procedures.

Methods

All patients who underwent operations (primary or revisional) in a 3-year period were retrospectively studied after bariatric surgery with a specific focus on the routinely assessed clinical parameters (tachycardia, temperature), paraclinical parameters on postoperative day (POD) 1 and 3 (C-reactive protein (CRP), leukocytes), and additional computed tomography (CT) scan results for the diagnosis of leakage, bleeding, intraabdominal abscess, superficial abscess, and other complications.

Results

A total of 587 patients were examined. In this cohort, 73 CT scans were performed due to suspected intraabdominal or pulmonary complication according to our hospital standard operating procedure. In total, 14 patients (2.4%) had a major complication (Clavien-Dindo grade IV/V). Of those, 10 patients (1.7%) had postoperative leakage. While the correct leakage diagnosis was only found in 33% of the patients by CT scan, the overall specificity of CT as a diagnostic tool for all kinds of complications remained high. Especially for abscess detection, CT scan showed a sensitivity and specificity of 100%. Multivariate analysis showed a significantly higher risk of leakage development characterized by a doubling of postoperative CRP level (odds ratio 4.84 (95% confidence interval 2.01–11.66, p < 0.001)). To simplify the use of CRP as a predictive factor for the diagnosis of leakage, a cut-off value of 2.4 was determined for the CRP quotient (POD3/POD1) with a sensitivity of 0.88 and a specificity of 0.89.

Conclusion

CT diagnostic after bariatric surgery has a high positive predictive value, especially for intraabdominal abscess formation. Nevertheless, CT scan for the diagnosis of leakage has a low sensitivity. Thus, a negative CT scan does not exclude the presence of a leakage. Using the described CRP quotient with a cut-off of 2.4, the risk of early leakage can be easily estimated. Furthermore, in any uncertain case of clinically suspected leakage, diagnostic laparoscopy should be performed.

Epigenetic Downregulation of FASN in Visceral Adipose Tissue of Insulin Resistant Subjects

OBJECTIVE

The risk to develop type 2 diabetes increases with the amount of visceral adiposity presumably due to increased lipolysis and subsequent lipid accumulation in visceral organs. However, data describing the molecular regulation of these pathways in humans are rare. We tested if genes of the lipogenic and lipolytic pathways are associated with glucose intolerance independently of obesity in visceral adipose tissue (VAT) of obese subjects. Moreover, we studied DNA methylation of FASN (fatty acid synthase), that catalyses the synthesis of long-chain fatty acids, in VAT of the same subjects and whether it is associated with metabolic traits.

SUBJECTS AND METHODS

Visceral adipose tissue biopsies and blood samples were taken from 93 severely obese subjects undergoing bariatric surgery. Subjects were grouped in low HbA1c (L-HbA1c, HbA1c<6.5 %) and high HbA1c (H-HbA1c, HbA1c≥6.5 %) groups and expression of genes from the lipogenic and lipolytic pathways was analysed by TaqMan qPCR. DNA methylation of FASN was quantified by bisulfite-pyrosequencing.

RESULTS

FASN expression was downregulated in visceral fat from subjects with high HbA1c (p = 0.00009). Expression of other lipogenetic (SCD, ELOVL6) or lipolytic genes (ADRB3, PNPLA2) and FABP4 was not changed. DNA methylation of FASN was increased at a regulatory ChoRE recognition site in the H-HbA1c-subgroup and correlated negatively with FASN mRNA (r = - 0.302, p = 0.0034) and positively with HbA1c (r = 0.296, p = 0.0040) and blood glucose (r = 0.363, p = 0.0005).

CONCLUSIONS

Epigenetic downregulation of FASN in visceral adipose tissue of obese subjects might contribute to limited de novo lipogenesis of important insulin sensitizing fatty acids and could thereby contribute to glucose intolerance and the development of type 2 diabetes independently of obesity.

Mentorship Programs in Bariatric Surgery Reduce Perioperative Complication Rate at Equal Short-Term Outcome-Results from the OPTIMIZE Trial

OBJECTIVES

The aim of this study was to determine the efficacy of coaching on outcome in low volume centers of excellence and to evaluate the influence of mentorship programs on the center development.

BACKGROUND

The number of bariatric procedures has increased steadily in the last years. Providing nationwide bariatric care on a high professional level needs structures to train and guide upcoming centers and ensure high quality in patient care.

METHODS

A prospective multicentered, observational study including laparoscopic sleeve gastrectomies (SG) and Roux-en-Y gastric bypass (RYGB) procedures was performed. Twelve emerging bariatric centers were coached by five experienced bariatric centers. Surgeons of the mentor centers gave guidance on pre- and postsurgical management of their patients including complications and proctored the first interventions. The results were compared regarding operative outcomes, percentage of excess weight loss, complications, and resolution of comorbidities.

RESULTS

A total of 214 of 293 patients (73.0%) completed the study. The most frequently reported complications were wound infection (4.4%), disorder of emptying stomach/new reflux (2.4%), anastomotic leaks, intra-abdominal secondary hemorrhage, and dumping syndrome (2.0% each). The mortality rate was zero. We found no difference in overall complication rates or resolution of obesity-related comorbidities when comparing experienced surgeons with less experienced surgeons.

CONCLUSIONS

Our results suggest that under the conditions of the practices of this study, coaching and mentoring were associated with comparable outcomes both in experienced and emerging centers. In addition, mentorship programs ensure equal outcome quality in terms of improvement of obesity-associated comorbidities.

TRIAL REGISTRATION

NCT Number: NCT01754194 .

Critical evaluation of the DNA-methylation markers ABCG1 and SREBF1 for Type 2 diabetes stratification

Aim: Validation of epigenome-wide association studies is sparse. Therefore, we evaluated the methylation markers cg06500161 (ABCG1) and cg11024682 (SREBF1) as classifiers for diabetes stratification. Patients & methods: DNA methylation was measured in blood (n = 167), liver (n = 99) and visceral adipose tissue (n = 99) of nondiabetic or Type 2 diabetic subjects by bisulfite pyrosequencing. Results: DNA methylation at cg11024682 in blood and liver correlated with BMI. Methylation at cg06500161 was influenced by the adjacent SNP rs9982016. Insulin-resistant and sensitive subjects could be stratified by DNA methylation status in blood or visceral adipose tissue. Conclusion: DNA methylation at both loci in blood presents a promising approach for risk group stratification and could be valuable for personalized Type 2 diabetes risk prediction in the future.

Reduced expression of thyroid hormone receptor β in human nonalcoholic steatohepatitis

Hepatic thyroid hormone signaling has an important role in the development and progression of nonalcoholic steatohepatitis (NASH). While the systemic levels of thyroid hormone might remain stable, there is evidence that the intracellular signaling machinery consisting of transporters, deiodinases and receptors could be altered in NASH. However, clinical material from human liver biopsies of individuals with NASH has not been studied to date. In a cross-sectional study, we analyzed 85 liver biopsies from patients with different stages of NASH that underwent bariatric surgery. Using qPCR, we analyzed gene expression of thyroid hormone transporters NTCP (SLC10A1), MCT8 (SLC16A2) and OATP1C1 (SLCO1C1), thyroid hormone receptor α and β (THRA and THRB) and deiodinase type I, II and III (DIO1, DIO2, DIO3). The expression was correlated with serum TSH, triglyceride, HbA1c and NASH score and corrected for age or gender if required. While DIO2, DIO3 and SLCO1C1 were not expressed in human liver, we observed a significant negative correlation of THRB and DIO1 with age, and SLC16A2 with gender. THRB expression was also negatively associated with serum triglyceride levels and HbA1c. More importantly, its expression was inversely correlated with NASH score and further declined with age. Our data provide unique insight into the mRNA expression of thyroid hormone transporters, deiodinases and receptors in the human liver. The findings allow important conclusions on the intrahepatic mechanisms governing thyroid hormone action, indicating a possible tissue resistance to the circulating hormone in NASH, which becomes more prominent in advanced age.

Improved Risk Stratification by Circulating Tumor Cell Counts in Pancreatic Cancer

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Upper Gastrointestinal Endoscopy prior to Bariatric Surgery-Mandatory or Expendable? An Analysis of 801 Cases

BACKGROUND

Upper gastrointestinal pathologies are common in bariatric patients. Preoperative esophagogastroduodenal endoscopy (EGD) should detect and treat pathologies that might alter the type of bariatric surgery. However, clinical consequences of these findings are often insignificant. The aim of this study was to assess the influence of preoperative endoscopy in our cohort and its clinical consequences.

METHODS

We conducted a retrospective analysis of endoscopic findings in patients under evaluation for bariatric surgery. Endoscopic findings were compared to preoperative risk factors as well as postoperative complications, and its clinical consequences were analyzed.

RESULTS

Data was available for 801 patients. Abnormal endoscopic findings were found in 65.7% of all patients. The most common conditions were gastritis (32.1%) and gastroesophageal reflux (24.8%). Malignancies were observed in 0.5% of all patients. We observed early-stage adenocarcinoma of the esophagus in two patients through our routine preoperative evaluation. Helicobacter pylori infections were detected in preoperative biopsies in only 3.7% of all patients. Patients who reported reflux symptoms had a higher rate of pathological EGDs (74.2 vs. 64.9%, p .019). We did not find any other risk factors for a pathological endoscopy. The postoperative complication rate was 11.2%. Leakage rate was 1.1%. Mortality rate was 0.4%. We did not find any correlation between the incidence of postoperative complications and preoperative endoscopic findings.

CONCLUSIONS

Relevant findings in routine preoperative endoscopy are rare but have significant influence on decision-making in bariatric patients and should be assessed as a necessary diagnostic tool.

Driving performance at lateral system limits during partially automated driving

This study investigated driver performance during system limits of partially automated driving. Using a motion-based driving simulator, drivers encountered different situations in which a partially automated vehicle could no longer safely keep the lateral guidance. Drivers were distracted by a non-driving related task on a touch display or driving without an additional secondary task. While driving in partially automated mode drivers could either take their hands off the steering wheel for only a short period of time (10s, so-called 'Hands-on' variant) or for an extended period of time (120s, so-called 'Hands-off' variant). When the system limit was reached (e.g., when entering a work zone with temporary lines), the lateral vehicle control by the automation was suddenly discontinued and a take-over request was issued to the drivers. Regardless of the hands-off interval and the availability of a secondary task, all drivers managed the transition to manual driving safely. No lane exceedances were observed and the situations were rated as 'harmless' by the drivers. The lack of difference between the hands-off intervals can be partly attributed to the fact that most of the drivers kept contact to the steering wheel, even in the hands-off condition. Although all drivers were able to control the system limits, most of them could not explain why exactly the take-over request was issued. The average helpfulness of the take-over request was rated on an intermediate level. Consequently, providing drivers with information about the reason for a system limit can be recommended.

Biphasic aggregation of a perylene bisimide dye identified by exciton-vibrational spectra

The quantum efficiency of light emission supramolecular aggregates strongly depends on the intermolecular coupling. We present a molecule which demonstrates two different aggregated structures with high and low quantum efficiency. The spectral signatures can be understood by simulating the aggregated structures and the corresponding exciton-vibrational spectra.

[Effect of body position on coordination of breathing and swallowing]

BACKGROUND

To allow passage of food, the swallowing process closes off the larynx and interrupts respiratory flow. Both the timing of the interruption of respiratory flow and the body position can affect the results of the swallowing process.

OBJECTIVE

The effect of body position on the swallowing process and the coordination of breathing and swallowing is investigated.

MATERIALS AND METHOD

A combined EMG/bioimpedance measurement system and a piezoelectric sensor were used to investigate coordination of breathing and swallowing of a range of food consistencies in three different body positions (90°, 45° and 0°) in healthy subjects.

RESULTS

Investigations were carried out on 21 healthy subjects (12 ♂, 9 ♀). 762 swallows were recorded. Changing body position was found to have a statistically significant effect on swallow-related parameters (maximum laryngeal elevation and speed of laryngeal elevation) and breathing pattern (pre- and post-swallow breathing phases). The laryngeal elevation as well as the speed of the laryngeal elevation is influenced significantly by the consistency to be swallowed. The breathing pattern changes from saliva to solid food of inspiration/swallow/inspiration to expiration/swallow/expiration. A change of body position influences the parameters specific for swallowing and the breathing patterns significantly.

CONCLUSIONS

This study demonstrates that body position affects coordination of breathing and swallowing and swallow-related parameters in healthy subjects. Our results indicate that patients should be enabled to adopt a position in which they are sitting at an angle of at least 45°.

Obesity research: Status quo and future outlooks

Obesity is a multifactorial disease showing a pandemic increase within the last decades in developing, and developed countries. It is associated with several severe comorbidities such as type II diabetes, hypertension, sleep apnea, non-alcoholic steatosis hepatis and cancer. Due to the increasing number of overweight individuals worldwide, research in the field of obesity has become more vital than ever. Currently, great efforts are spend to understand this complex disease from a biological, psychological and sociological angle. Further insights of obesity research come from bariatric surgery that provides new information regarding hormonal changes during weight loss. The initiation of programs for obesity treatment, both interventional and pharmaceutical, are being pursued with the fullest intensity. Currently, bariatric surgery is the most effective therapy for weight loss and resolution of comorbidities in morbid obese patients. Reasons for weight loss and remission of comorbidities following Roux-en-Y-Gastric Bypass, Sleeve Gastrectomy, and other bariatric procedures are therefore under intense investigation. In this review, however, we will focus on obesity treatment, highlighting new insights and future trends of gut hormone research, the relation of obesity and cancer development via the obesity induced chronic state of inflammation, and new potential concepts of interventional and conservative obesity treatment.

Minimalinvasive Chirurgie bei Malignomen des Gastrointestinaltrakts: Ösophagus - Pro-Position

<b><i>Hintergrund: </i></b>Die offene onkologische Resektion ist derzeit der Goldstandard in der Behandlung des Plattenepithel- und Adenokarzinoms des Ösophagus. Die mit den Therapieverfahren assoziierte Morbidität und Mortalität konnte in den letzten Jahren durch die Verbesserung des chirurgischen und perioperativen Managements deutlich gesenkt werden, bleibt aber im Vergleich zu anderen Eingriffen am Gastrointestinaltrakt weiterhin hoch. <b><i>Methoden: </i></b>Diese Übersicht basiert auf einer strukturierten Analyse der aktuellen, in MEDLINE, PubMed, EMBASE und den Cochrane Databases gelisteten Studien. <b><i>Ergebnisse: </i></b>In den letzten 20 Jahren sind zunehmend Arbeiten erschienen, die seit der Erstbeschreibung der minimalinvasiven Ösophagusresektion zeigen, dass in entsprechend erfahrenen Zentren die hohe Morbidität und Mortalität, insbesondere für pulmonale Komplikationen durch minimalinvasive Ösophagusresektionen, drastisch gesenkt werden konnte - ohne Verzicht auf onkologische Radikalität und ohne Verschlechterung des onkologischen Outcomes. Die postoperative Lebensqualität war ebenfalls nicht schlechter für minimalinvasiv operierte Patienten. Allerdings sind die minimalinvasiven Techniken im Bereich der Ösophaguschirurgie mit einer signifikanten Lernkurve verbunden - ein weiteres Argument für eine Zentralisierung der Ösophaguschirurgie. <b><i>Schlussfolgerungen: </i></b>Die bisher erhobenen Daten zur minimalinvasiven Ösophagusresektion sind zwar sehr vielversprechend, jedoch sind weitere kontrollierte randomisierte Studien erforderlich, um die bisher erhobenen Daten zu erhärten.

Investigation of the suitability of tissue phantoms for testing the constancy of ultrasonic transducer arrays in quality assurance

PURPOSE

To ensure high quality ultrasound diagnostics, proper functioning of the devices used is a necessary prerequisite. Ultrasound transducers have proven to be the most failure-prone part of the signal chain. Their technical monitoring is possible in principle with the help of tissue phantoms. The background of the present study is to determine which type of phantoms and which measurement parameters are best suited to a consistency test as part of routine quality assurance of ultrasound imaging systems.

MATERIALS AND METHODS

A classic wire-type phantom (ATS Mod. 539, ATS Labs Bridgeport, USA) and a 3 D cyst phantom (TCC, Timelkam, Austria) were used for the studies and comparative tests were conducted between intact transducers and those in which faults had been simulated. The collected measurement data show a relatively large scatter. Therefore, statistical analysis methods were used, and the discrimination analysis proved to be a useful tool.

RESULTS

Local failures which arise, e. g. due to the breakdown of individual piezoelectric elements or element groups in the transducer array, can be detected with the help of the gray value targets of the ATS phantom, but only in those cases in which the error-affected sound field part actually overlaps with the target under consideration. The TCC phantom is not suitable for the detection of such errors. Global transducer failures, i. e. those that affect the entire array, can even be detected with both types of phantoms.

CONCLUSION

When the emphasis of quality assessment is on the detection of local defects in the array that make up the largest part of the transducer faults, studies with conventional phantoms are only of limited value.