Whole-body [18F]-FDG-PET/MRI for staging of pediatric non-Hodgkin lymphoma: first results from a single-center evaluation

Aim

In 2015, the revised International Pediatric Non-Hodgkin Lymphoma Staging System was published. It mentions [¹⁸F]-FDG-PET/MRI as the latest method to perform whole-body imaging. However, supporting data are pending. Our aim was to investigate the performance of whole-body [¹⁸F]-FDG-PET/MRI in pediatric non-Hodgkin lymphoma patients by using a limited number of MRI sequences.

Materials and methods

Ten pediatric patients with histologically proven non-Hodgkin lymphoma underwent whole-body [¹⁸F]-FDG-PET/MRI at staging. The retrospective analysis included three steps: First, [¹⁸F]-FDG-PET and MR scans were evaluated separately by a nuclear medicine physician and a pediatric radiologist. Nineteen nodal and two extranodal regions as well as six organs were checked for involvement. Second, discrepant findings were reviewed together in order to reach consensus. Third, [¹⁸F]-FDG-PET/MRI findings were correlated with the results of other clinical investigations.

Results

Of the 190 lymph node regions evaluated, four were rated controversial. Consensus was reached by considering metabolic, functional and morphologic information combined. Concordantly, [¹⁸F]-FDG-PET and MRI detected Waldeyer’s ring involvement in two patients whose Waldeyer’s ring was negative on clinical assessment. In four patients MRI showed pleural effusion. However, in only two of them an increased glucose metabolism as a reliable sign of pleural involvement was detectable. In six patients [¹⁸F]-FDG-PET and MRI detected skeletal lesions although bone marrow biopsy was positive in only one of them.

Conclusion

Despite the small number of cases evaluated, whole-body [¹⁸F]-FDG-PET turned out to be a valuable tool for staging of pediatric non-Hodgkin lymphoma.

[Which patient needs controls of laboratory values after elective laparoscopic cholecystectomy?-Can a score help?]

BACKGROUND

Laparoscopic cholecystectomy is nearly exclusively carried out as an inpatient operation in Germany. The aim of the study was to evaluate for which patients postoperative laboratory control values are necessary.

METHODS

This retrospective analysis included 100 patients who underwent elective laparoscopic cholecystectomy. A scoring and data collection sheet was developed, which enables a risk stratification. Using the scoring system patients can achieve between 3 and 15 points.

RESULTS

In total 100 patients were included in the study. Of the patients 64 (group 1) had between 3 and 8 points, 29 patients (group 2) between 9 and 11 points and 7 patients (group 3) between 12 and 15 points. In comparison to group 1 the C‑reactive protein values as well as the duration of hospital stay were significantly increased in group 2 and group 3 (p > 0.05). In group1 a total of 60 patients (93.7%) were discharged regularly on postoperative days 1-3. In group 2 there were 17 patients (58.6%) who could be discharged with unremarkable blood values and in group 3 there were 3 patients (42.8%). In the total collective hospital discharge without a laboratory control of blood values would have been justified in 80% of the patients.

CONCLUSION

A postoperative control of laboratory blood values is not routinely necessary for patients after elective laparoscopic cholecystectomy with a score <9 points.

Learning Curves of Laparoscopic Roux-en-Y Gastric Bypass and Sleeve Gastrectomy in Bariatric Surgery: a Systematic Review and Introduction of a Standardization

BACKGROUND

The most commonly performed bariatric procedures are laparoscopic Roux-en-Y gastric bypass (RYGB) and sleeve gastrectomy (LSG). Impact of learning curves on operative outcome has been well shown, but the necessary learning curves have not been clearly defined. This study provides a systematic review of the literature and proposes a standardization of phases of learning curves for RYGB and LSG.

METHODS

A systematic literature search was performed using PubMed, Web of Science, and CENTRAL databases. All studies specifying a number or range of approaches to characterize the learning curve for RYGB and LSG were selected.

RESULTS

A total of 28 publications related to learning curves for 27,770 performed bariatric surgeries were included. Parameters used to determine the learning curve were operative time, complications, conversions, length of stay, and blood loss. Learning curve range was 30-500 (RYGB) and 30-200 operations (LSG) according to different definitions and respective phases of learning curves. Learning phases described the number of procedures necessary to achieve predefined skill levels, such as competency, proficiency, and mastery.

CONCLUSIONS

Definitions of learning curves for bariatric surgery are heterogeneous. Introduction of the three skill phases competency, proficiency, and mastery is proposed to provide a standardized definition using multiple outcome variables to enable better comparison in the future. These levels are reached after 30-70, 70-150, and up to 500 RYGB, and after 30-50, 60-100, and 100-200 LSG. Training curricula, previous laparoscopic experience, and high procedure volume are hallmarks for successful outcomes during the learning curve.

Unexpected variations in posttranscriptional gene silencing induced by differentially produced dsRNAs in tobacco cells

In plants, posttranscriptional gene silencing (PTGS) is induced by small RNAs (sRNAs) generated from various dsRNA precursors. To assess the impact of dsRNA origin, we compared downregulation of GFP expression triggered by inverted repeat (IR), antisense (AS) and unterminated sense (UT) transcripts transiently expressed from the estradiol-inducible promoter. The use of homogeneously responding tobacco BY-2 cell lines allowed monitoring the onset of silencing and its reversibility. In this system, IR induced the strongest and fastest silencing accompanied by dense DNA methylation. At low induction, silencing in individual cells was binary (either strong or missing), suggesting that a certain threshold sRNA level had to be exceeded. The AS variant specifically showed a deviated sRNA-strand ratio shifted in favor of antisense orientation. In AS lines and weakly induced IR lines, only the silencer DNA was methylated, but the same target GFP sequence was not, showing that DNA methylation accompanying PTGS was influenced both by the level and origin of sRNAs, and possibly also by the epigenetic state of the locus. UT silencing appeared to be the least effective and resembled classical sense PTGS. The best responding UT lines behaved relatively heterogeneously possibly due to complexly arranged T-DNA insertions. Unlike IR and AS variants that fully restored GFP expression upon removal of the inducer, only partial reactivation was observed in some UT lines. Our results pointed out several not yet described phenomena and differences between the long-known silencer variants that may direct further research and affect selection of proper silencer variants for specific applications.

Development of a cost-effective automated platform to produce human liver spheroids for basic and applied research

Liver disease represents an increasing cause of global morbidity and mortality. Currently, liver transplant is the only treatment curative for end-stage liver disease. Donor organs cannot meet the demand and therefore scalable treatments and new disease models are required to improve clinical intervention. Pluripotent stem cells represent a renewable source of human tissue. Recent advances in three-dimensional cell culture have provided the field with more complex systems that better mimic liver physiology and function. Despite these improvements, current cell-based models are variable in performance and expensive to manufacture at scale. This is due, in part, to the use of poorly defined or cross-species materials within the process, severely affecting technology translation. To address this issue, we have developed an automated and economical platform to produce liver tissue at scale for modelling disease and small molecule screening. Stem cell derived liver spheres were formed by combining hepatic progenitors with endothelial cells and stellate cells, in the ratios found within the liver. The resulting tissue permitted the study of human liver biology 'in the dish' and could be scaled for screening. In summary, we have developed an automated differentiation system that permits reliable self-assembly of human liver tissue for biomedical application. Going forward we believe that this technology will not only serve as anin vitroresource, and may have an important role to play in supporting failing liver function in humans.

Health status of free-ranging ring-necked pheasant chicks (Phasianus colchicus) in North-Western Germany

Being a typical ground-breeding bird of the agricultural landscape in Germany, the pheasant has experienced a strong and persistent population decline with a hitherto unexplained cause. Contributing factors to the ongoing negative trend, such as the effects of pesticides, diseases, predation, increase in traffic and reduced fallow periods, are currently being controversially discussed. In the present study, 62 free-ranging pheasant chicks were caught within a two-year period in three federal states of Germany; Lower Saxony, North Rhine-Westphalia and Schleswig-Holstein. The pheasant chicks were divided into three age groups to detect differences in their development and physical constitution. In addition, pathomorphological, parasitological, virological, bacteriological and toxicological investigations were performed. The younger chicks were emaciated, while the older chicks were of moderate to good nutritional status. However, the latter age group was limited to a maximum of three chicks per hen, while the youngest age class comprised up to ten chicks. The majority of chicks suffered from dermatitis of the periocular and caudal region of the head (57-94%) of unknown origin. In addition, intestinal enteritis (100%), pneumonia (26%), hepatitis (24%), perineuritis (6%), tracheitis (24%), muscle degeneration (1%) and myositis (1%) were found. In 78% of the cases, various Mycoplasma spp. were isolated. Mycoplasma gallisepticum (MG) was not detected using an MG-specific PCR. Parasitic infections included Philopteridae (55%), Coccidia (48%), Heterakis/Ascaridia spp. (8%) and Syngamus trachea (13%). A total of 8% of the chicks were Avian metapneumovirus (AMPV) positive using RT-PCR, 16% positive for infectious bronchitis virus (IBV) using RT-PCR, and 2% positive for haemorrhagic enteritis virus (HEV) using PCR. All samples tested for avian encephalomyelitis virus (AEV), infectious bursal disease virus (IBDV) or infectious laryngotracheitis virus (ILTV) were negative. The pool samples of the ten chicks were negative for all acid, alkaline-free and derivative substances, while two out of three samples tested were positive for the herbicide glyphosate. Pheasant chick deaths may often have been triggered by poor nutritional status, probably in association with inflammatory changes in various tissues and organs as well as bacterial and parasitic pathogens. Theses impacts may have played a major role in the decline in pheasant populations.

Size-dependent influence of NOx on the growth rates of organic aerosol particles

Atmospheric new-particle formation (NPF) affects climate by contributing to a large fraction of the cloud condensation nuclei (CCN). Highly oxygenated organic molecules (HOMs) drive the early particle growth and therefore substantially influence the survival of newly formed particles to CCN. Nitrogen oxide (NOx) is known to suppress the NPF driven by HOMs, but the underlying mechanism remains largely unclear. Here, we examine the response of particle growth to the changes of HOM formation caused by NOx. We show that NOx suppresses particle growth in general, but the suppression is rather nonuniform and size dependent, which can be quantitatively explained by the shifted HOM volatility after adding NOx. By illustrating how NOx affects the early growth of new particles, a critical step of CCN formation, our results help provide a refined assessment of the potential climatic effects caused by the diverse changes of NOx level in forest regions around the globe.

Consensus on definition and severity grading of lymphatic complications after kidney transplantation

BACKGROUND

The incidence of lymphatic complications after kidney transplantation varies considerably in the literature. This is partly because a universally accepted definition has not been established. This study aimed to propose an acceptable definition and severity grading system for lymphatic complications based on their management strategy.

METHODS

Relevant literature published in MEDLINE and Web of Science was searched systematically. A consensus for definition and a severity grading was then sought between 20 high-volume transplant centres.

RESULTS

Lymphorrhoea/lymphocele was defined in 32 of 87 included studies. Sixty-three articles explained how lymphatic complications were managed, but none graded their severity. The proposed definition of lymphorrhoea was leakage of more than 50 ml fluid (not urine, blood or pus) per day from the drain, or the drain site after removal of the drain, for more than 1 week after kidney transplantation. The proposed definition of lymphocele was a fluid collection of any size near to the transplanted kidney, after urinoma, haematoma and abscess have been excluded. Grade A lymphatic complications have a minor and/or non-invasive impact on the clinical management of the patient; grade B complications require non-surgical intervention; and grade C complications require invasive surgical intervention.

CONCLUSION

A clear definition and severity grading for lymphatic complications after kidney transplantation was agreed. The proposed definitions should allow better comparisons between studies.

[Patient blood management : Medical concept for increasing patient safety]

Patient blood management (PBM) is a multidisciplinary evidence-based treatment model. Aims are to provide treatment of pre-existing or recently occureed deficits in blood volume and of substances that are important for erythropoiesis in patients, as well as the targeted administration of cellular and non-cellular blood products within reasonable and scientifically proven limits. The overall goal is therefore a safe therapy and complication-free course of the disease. PBM follows a strategy based on three pillars, which encompasses the aspects of optimization of anemia and hemoglobin, the handling of bleeding and the use of patient-related resources.

Fast Peroxy Radical Isomerization and OH Recycling in the Reaction of OH Radicals with Dimethyl Sulfide

Dimethyl sulfide (DMS), produced by marine organisms, represents the most abundant, biogenic sulfur emission into the Earth's atmosphere. The gas-phase degradation of DMS is mainly initiated by the reaction with the OH radical forming first CH₃SCH₂O₂ radicals from the dominant H-abstraction channel. It is experimentally shown that these peroxy radicals undergo a two-step isomerization process finally forming a product consistent with the formula HOOCH₂SCHO. The isomerization process is accompanied by OH recycling. The rate-limiting first isomerization step, CH₃SCH₂O₂ → CH₂SCH₂OOH, followed by O₂ addition, proceeds with k = (0.23 ± 0.12) s^-1 at 295 ± 2 K. Competing bimolecular CH₃SCH₂O₂ reactions with NO, HO₂, or RO₂ radicals are less important for trace-gas conditions over the oceans. Results of atmospheric chemistry simulations demonstrate the predominance (≥95%) of CH₃SCH₂O₂ isomerization. The rapid peroxy radical isomerization, not yet considered in models, substantially changes the understanding of DMS's degradation processes in the atmosphere.

Detailed insight into the dynamics of the initial phases of de novo RNA-directed DNA methylation in plant cells

BACKGROUND

Methylation of cytosines is an evolutionarily conserved epigenetic mark that is essential for the control of chromatin activity in many taxa. It acts mainly repressively, causing transcriptional gene silencing. In plants, de novo DNA methylation is established mainly by RNA-directed DNA-methylation pathway. Even though the protein machinery involved is relatively well-described, the course of the initial phases remains covert.

RESULTS

We show the first detailed description of de novo DNA-methylation dynamics. Since prevalent plant model systems do not provide the possibility to collect homogenously responding material in time series with short intervals, we developed a convenient system based on tobacco BY-2 cell lines with inducible production of siRNAs (from an RNA hairpin) guiding the methylation machinery to the CaMV 35S promoter controlling GFP reporter. These lines responded very synchronously, and a high level of promoter-specific siRNAs triggered rapid promoter methylation with the first increase observed already 12 h after the induction. The previous presence of CG methylation in the promoter did not affect the methylation dynamics. The individual cytosine contexts reacted differently. CHH methylation peaked at about 80% in 2 days and then declined, whereas CG and CHG methylation needed more time with CHG reaching practically 100% after 10 days. Spreading of methylation was only minimal outside the target region in accordance with the absence of transitive siRNAs. The low and stable proportion of 24-nt siRNAs suggested that Pol IV was not involved in the initial phases.

CONCLUSIONS

Our results show that de novo DNA methylation is a rapid process initiated practically immediately with the appearance of promoter-specific siRNAs and independently of the prior presence of methylcytosines at the target locus. The methylation was precisely targeted, and its dynamics varied depending on the cytosine sequence context. The progressively increasing methylation resulted in a smooth, gradual inhibition of the promoter activity, which was entirely suppressed in 2 days.

Tubulin is actively exported from the nucleus through the Exportin1/CRM1 pathway

Microtubules of all eukaryotic cells are formed by α- and β-tubulin heterodimers. In addition to the well known cytoplasmic tubulins, a subpopulation of tubulin can occur in the nucleus. So far, the potential function of nuclear tubulin has remained elusive. In this work, we show that α- and β-tubulins of various organisms contain multiple conserved nuclear export sequences, which are potential targets of the Exportin 1/CRM1 pathway. We demonstrate exemplarily that these NES motifs are sufficient to mediate export of GFP as model cargo and that this export can be inhibited by leptomycin B, an inhibitor of the Exportin 1/CRM1 pathway. Likewise, leptomycin B causes accumulation of GFP-tagged tubulin in interphase nuclei, in both plant and animal model cells. Our analysis of nuclear tubulin content supports the hypothesis that an important function of nuclear tubulin export is the exclusion of tubulin from interphase nuclei, after being trapped by nuclear envelope reassembly during telophase.

Plant Cell Lines in Cell Morphogenesis Research: From Phenotyping to -Omics

Here we provide an overview of procedures for long-term cultivation, phenotyping, genotyping, and genetic transformation of cell cultures of tobacco cell lines BY-2 and VBI-0, and of A. thaliana, ecotype Landsberg erecta (LE) cell line. Notably, we present an improved protocol for BY-2 transformation and cloning and extend the available plant cell lines methodology toward high-throughput technologies like fluorescent-based cell sorting and transcriptomics.

Pervasive read-through transcription of T-DNAs is frequent in tobacco BY-2 cells and can effectively induce silencing

BACKGROUND

Plant transformation via Agrobacterium tumefaciens is characterized by integration of commonly low number of T-DNAs at random positions in the genome. When integrated into an active gene region, promoterless reporter genes placed near the T-DNA border sequence are frequently transcribed and even translated to reporter proteins, which is the principle of promoter- and gene-trap lines.

RESULTS

Here we show that even internal promotorless regions of T-DNAs are often transcribed. Such spontaneous transcription was observed in the majority of independently transformed tobacco BY-2 lines (over 65%) and it could effectively induce silencing if an inverted repeat was present within the T-DNA. We documented that the transcription often occurred in both directions. It was not directly connected with any regulatory elements present within the T-DNAs and at least some of the transcripts were initiated outside of the T-DNA. The likeliness of this read-through transcription seemed to increase in lines with higher T-DNA copy number. Splicing and presence of a polyA tail in the transcripts indicated involvement of Pol II, but surprisingly, the transcription was able to run across two transcription terminators present within the T-DNA. Such pervasive transcription was observed with three different T-DNAs in BY-2 cells and with lower frequency was also detected in Arabidopsis thaliana.

CONCLUSIONS

Our results demonstrate unexpected pervasive read-through transcription of T-DNAs. We hypothesize that it was connected with a specific chromatin state of newly integrated DNA, possibly affected by the adjacent genomic region. Although this phenomenon can be easily overlooked, it can have significant consequences when working with highly sensitive systems like RNAi induction using an inverted repeat construct, so it should be generally considered when interpreting results obtained with the transgenic technology.

Severe Case of Chronic Pelvic Pain Syndrome: Recovery after Injection of Procaine into the Vesicoprostatic Plexus-Case Report and Discussion of Pathophysiology and Mechanisms of Action

We describe a patient with a 35-year history of a severe chronic pelvic pain syndrome (CPPS) that failed to adequately respond to various drug therapies and other treatments by different specialists. In addition to the ongoing chronic pain, he suffered from week-long episodes of increased pain with no discernible trigger. At the first consultation with us the patient was in a particularly severe pain phase. He was taking four different analgesically effective drugs. In terms of therapeutic local anesthesia (neural therapy), we performed suprapubic injection of procaine 1% with infiltration of the vesicoprostatic plexus. Just a few minutes later, the pain decreased significantly. To maintain and further increase the effect, we performed the injection six more times. The patient gradually reduced and stopped all drugs and remained free of pain and discomfort ever since. This is the first report of a successful therapeutic infiltration of the vesicoprostatic plexus using a local anesthetic (LA) in a patient with CPPS that has been refractory to different treatments for many years. A possible explanation may be that the positive feedback loops maintaining pain and neurogenic inflammation are disrupted by LA infiltration. This can lead to a new organisation (self-organisation) of the pain-processing systems.

Stabilisation of acute-on-chronic liver failure patients before liver transplantation predicts post-transplant survival

BACKGROUND

Acute-on-chronic liver failure (ACLF) is a severe complication of liver cirrhosis associated with excess short-term mortality rates. Orthotopic liver transplantation (OLT) is a potentially life-saving therapeutic modality for acute-on-chronic liver failure patients, but selection of transplant candidates with an acceptable post-transplant outcome is difficult.

AIM

To assess the risk of liver transplantation in patients with ACLF, and to determine parameters that predict post-transplant survival in this patient cohort.

METHODS

We retrospectively analysed all 250 patients with cirrhosis who underwent their first liver transplantation between 2009 and 2014 at our institution, and assessed post-transplant outcomes.

RESULTS

Of 250 cirrhotic liver transplant recipients, 98 patients fulfilled the diagnostic criteria for acute-on-chronic liver failure in the 3-month pre-transplant period. Compared to non-ACLF patients, ACLF was associated with significantly higher short-term morbidity and mortality after liver transplantation (90-day patient survival 96.1% non-ACLF vs 72.4% ACLF patients, P < 0.0001). Clinical improvement in the pre-transplant period, as defined by recovery of at least one previously failed organ system, was observed in 37 of 98 acute-on-chronic liver failure patients, mostly within several days after diagnosis. Most notably, clinical improvement prior to liver transplantation was associated with excellent post-transplant survival rates that approximated non-ACLF transplant recipients. Following the 90-day post-transplant period, patient survival and long-term graft functions were comparable between ACLF and non-ACLF liver transplant recipients for up to 5 years.

CONCLUSIONS

Acute-on-chronic liver failure predicts adverse outcome after orthotopic liver transplantation. Given the dismal prognosis without transplantation, however, our results indicate that ACLF patients can be transplanted with comparably good outcomes, in particular patients who improve under conservative therapeutic measures.

LapTrain: multi-modality training curriculum for laparoscopic cholecystectomy-results of a randomized controlled trial

BACKGROUND

Multiple training modalities for laparoscopy have different advantages, but little research has been conducted on the benefit of a training program that includes multiple different training methods compared to one method only. This study aimed to evaluate benefits of a combined multi-modality training program for surgical residents.

METHODS

Laparoscopic cholecystectomy (LC) was performed on a porcine liver as the pre-test. Randomization was stratified for experience to the multi-modality Training group (12 h of training on Virtual Reality (VR) and box trainer) or Control group (no training). The post-test consisted of a VR LC and porcine LC. Performance was rated with the Global Operative Assessment of Laparoscopic Skills (GOALS) score by blinded experts.

RESULTS

Training (n = 33) and Control (n = 31) were similar in the pre-test (GOALS: 13.7 ± 3.4 vs. 14.7 ± 2.6; p = 0.198; operation time 57.0 ± 18.1 vs. 63.4 ± 17.5 min; p = 0.191). In the post-test porcine LC, Training had improved GOALS scores (+ 2.84 ± 2.85 points, p < 0.001), while Control did not (+ 0.55 ± 2.34 points, p = 0.154). Operation time in the post-test was shorter for Training vs. Control (40.0 ± 17.0 vs. 55.0 ± 22.2 min; p = 0.012). Junior residents improved GOALS scores to the level of senior residents (pre-test: 13.7 ± 2.7 vs. 18.3 ± 2.9; p = 0.010; post-test: 15.5 ± 3.4 vs. 18.8 ± 3.8; p = 0.120) but senior residents remained faster (50.1 ± 20.6 vs. 25.0 ± 1.9 min; p < 0.001). No differences were found between groups on the post-test VR trainer.

CONCLUSIONS

Structured multi-modality training is beneficial for novices to improve basics and overcome the initial learning curve in laparoscopy as well as to decrease operation time for LCs in different stages of experience. Future studies should evaluate multi-modality training in comparison with single modalities.

TRIAL REGISTRATION

German Clinical Trials Register DRKS00011040.

Meta-analysis of metabolic surgery versus medical treatment for microvascular complications in patients with type 2 diabetes mellitus

Background

This study aimed to examine the effect of metabolic surgery on pre-existing and future microvascular complications in patients with type 2 diabetes mellitus (T2DM) in comparison with medical treatment. Although metabolic surgery is the most effective treatment for obese patients with T2DM regarding glycaemic control, it is unclear whether the incidence or severity of microvascular complications is reduced.

Methods

A systematic literature search was performed in MEDLINE, Embase, Web of Science and the Cochrane Central Register of Controlled Trials (CENTRAL) with no language restrictions, looking for RCTs, case–control trials and cohort studies that assessed the effect of metabolic surgery on the incidence of microvascular diabetic complications compared with medical treatment as control. The study was registered in the International prospective register of systematic reviews (CRD42016042994).

Results

The literature search yielded 1559 articles. Ten studies (3 RCTs, 7 controlled clinical trials) investigating 17 532 patients were included. Metabolic surgery reduced the incidence of microvascular complications (odds ratio 0·26, 95 per cent c.i. 0·16 to 0·42; P &lt; 0·001) compared with medical treatment. Pre-existing diabetic nephropathy was strongly improved by metabolic surgery versus medical treatment (odds ratio 15·41, 1·28 to 185·46; P = 0·03).

Conclusion

In patients with T2DM, metabolic surgery prevented the development of microvascular complications better than medical treatment. Metabolic surgery improved pre-existing diabetic nephropathy compared with medical treatment.

5-Azacytidine mediated reactivation of silenced transgenes in potato (Solanum tuberosum) at the whole plant level

Transient 5-azacytidine treatment of leaf explants from potato plants with transcriptionally silenced transgenes allows de novo regeneration of plants with restored transgene expression at the whole plant level. Transgenes introduced into plant genomes frequently become silenced either at the transcriptional or the posttranscriptional level. Transcriptional silencing is usually associated with DNA methylation in the promoter region. Treatments with inhibitors of maintenance DNA methylation were previously shown to allow reactivation of transcriptionally silenced transgenes in single cells or tissues, but not at the whole plant level. Here we analyzed the effect of DNA methylation inhibitor 5-azacytidine (AzaC) on the expression of two silenced reporter genes encoding green fluorescent protein (GFP) and neomycin phosphotransferase (NPTII) in potato plants. Whereas no obvious reactivation was observed in AzaC-treated stem cuttings, transient treatment of leaf segments with 10 μM AzaC and subsequent de novo regeneration of shoots on the selective medium with kanamycin resulted in the production of whole plants with clearly reactivated expression of previously silenced transgenes. Reactivation of nptII expression was accompanied by a decrease in cytosine methylation in the promoter region of the gene. Using the plants with reactivated GFP expression, we found that re-silencing of this transgene can be accidentally triggered by de novo regeneration. Thus, testing the incidence of transgene silencing during de novo regeneration could be a suitable procedure for negative selection of transgenic lines (insertion events) which have an inclination to be silenced. Based on our analysis of non-specific inhibitory effects of AzaC on growth of potato shoots in vitro, we estimated that AzaC half-life in the culture media is approximately 2 days.

Outcome and natural course of renal dysfunction in liver transplant recipients with severely impaired kidney function prior to transplantation

Background

Since introduction of the MELD score in the liver allograft allocation system, renal insufficiency has emerged as an increasing problem. Here we evaluated the course of kidney function in patients with advanced renal insufficiency prior to liver transplantation (LT).

Methods

A total of 254 patients undergoing LT at the University Medical Centre Hamburg-Eppendorf (2011-2015) were screened for renal impairment (GFR < 30 ml/min) prior to LT in this observational study.

Results

Eighty (32%) patients (median 60 years; M/F: 48/32) had significant renal impairment prior to LT. Median follow-up post-LT was 619 days. Patient survival at 90 days, one year and two years was 76%, 66% and 64%, respectively. Need for dialysis postoperatively but not preoperatively was associated with increased mortality (p < 0.05). Renal function improved in 75% of survivors, but 78% of patients had chronic kidney disease ≥ stage 3 at end of follow-up. Of eight (16%) survivors remaining on long-term dialysis, so far only four patients have received a kidney transplant.

Conclusion

Postoperative dialysis affected long-term mortality. In 75% of survivors renal function improved, but still the majority of patients had an impaired renal function (CKD stage 3-5) at end of follow-up. Future studies should elucidate the impact of kidney dysfunction and dialysis on recipients' long-term survival.

[The way from cost approval to bariatric surgery : Analysis of resource utilization in a maximum care hospital]

BACKGROUND

Morbid obesity is a medical and economic challenge. Patients who have the indications for bariatric surgery face a long way from the first visit until surgery and a high utilization of resources is required.

OBJECTIVES

The present study aimed to evaluate labor costs and labor time required to supervise obese patients from their first visit until preparation of a bariatric report to ask for cost acceptance of bariatric surgery from their health insurance. In addition, the reasons for not receiving bariatric surgery after receiving cost acceptance from the health insurance were evaluated.

MATERIAL AND METHODS

Patients who had indications for bariatric surgery according to the S3 guidelines between 2012 and 2013, were evaluated regarding labor costs and labor time of the process from the first visit until receiving cost acceptance from their health insurance. Furthermore, body mass index (BMI), age, sex, Edmonton Obesity Staging System (EOSS) stage and comorbidities were evaluated. Patients who had not received surgery up to December 2015 were contacted via telephone to ask for the reasons.

RESULTS

In the present study 176 patients were evaluated (110 females, 62.5%). Until preparation of a bariatric report the patients required an average of 2.7 combined visits in the department of surgery with the department of nutrition, 1.7 visits in the department of psychosomatic medicine, 1.5 separate visits in the department of nutrition and 1.4 visits in the department of internal medicine. Average labor costs from the first visit until the bariatric survey were 404.90 ± 117.00 euros and 130 out of 176 bariatric reports were accepted by the health insurance (73.8%). For another 40 patients a second bariatric survey was made and 20 of these (50%) were accepted, which results in a total acceptance rate of 85.2% (150 out of 176). After a mean follow-up of 2.8 ± 1.1 years only 93 out of 176 patients had received bariatric surgery (53.8%). Of these 16 had received acceptance of surgery by their health insurance only after a second bariatric survey.

CONCLUSION

A large amount of labor and financial resources are required for treatment of obese patients from first presentation up to bariatric surgery. The cost-benefit calculation of an obesity center needs to include that approximately one half of the patients do not receive surgery within more than 2.5 years.