Enhancing pre-clinical research with simplified intestinal cell line models

Two-dimensional culture remains widely employed to determine the bioavailability of orally delivered drugs. To gain more knowledge about drug uptake mechanisms and risk assessment for the patient after oral drug admission, intestinal in vitro models demonstrating a closer similarity to the in vivo situation are needed. In particular, Caco-2 cell-based Transwell® models show advantages as they are reproducible, cost-efficient, and standardized. However, cellular complexity is impaired and cell function is strongly modified as important transporters in the apical membrane are missing. To overcome these limitations, primary organoid-based human small intestinal tissue models were developed recently but the application of these cultures in pre-clinical research still represents an enormous challenge, as culture setup is complex as well as time- and cost-intensive. To overcome these hurdles, we demonstrate the establishment of primary organoid-derived intestinal cell lines by immortalization. Besides exhibiting cellular diversity of the organoid, these immortalized cell lines enable a standardized and more cost-efficient culture. Further, our cell line-based Transwell®-like models display an organ-specific epithelial barrier integrity, ultrastructural features and representative transport functions. Altogether, our novel model systems are cost-efficient with close similarity to the in vivo situation, therefore favoring their use in bioavailability studies in the context of pre-clinical screenings.

[Complications of the 180 Watt XPS™ GreenLight laser-results of 1283 procedures]

BACKGROUND

The aim of this study was to classify and analyze postoperative complications under a new inspection method. This study assessed all patients who presented to the urologic ward within the first 3 months after their surgery.

METHODS

A total of 170 patients suffered from complications due to the surgery; 29 patients experienced complications that were not directly correlated with the surgery. Age, American Society of Anesthesiologists (ASA) score, the emitted laser energy of the 180 Watt XPS™ GreenLight laser measured in joules, and the complications which led to the renewed hospitalization such as hematuria, urinary retention, and infection were analyzed and compared in the two groups of patients.

RESULTS

Most complications that occurred were urinary retention and hematuria (50.6% and 49.4% of all patients, respectively). Of the patients with hematuria, 86.75% were under anticoagulant therapy medication.

CONCLUSION

Compared with the reference approval study (Goliath trial) that included 135 multicentric patients (14.07% of patients presented with a complication classified as Clavien-Dindo II), the rate of complications was similar. This outcome is surprising because the patients treated with the GreenLight laser in the present study were classified as geriatric patients not only according to their age but also in their ASA score which is an indication of multiple other pathologies and administered medications. To achieve long-term postoperative success for these patients, the interface between the ambulatory and the hospital care should be optimized.

Histological evaluation of PAXgene tissue fixation in Barrett’s esophagus and esophageal adenocarcinoma diagnostics

The dysplasia grading of Barrett’s esophagus (BE), based on the histomorphological assessment of formalin-fixed, paraffin-embedded (FFPE) tissue, suffers from high interobserver variability leading to an unsatisfactory prediction of cancer risk. Thus, pre-analytic preservation of biological molecules, which could improve risk prediction in BE enabling molecular and genetic analysis, is needed. We aimed to evaluate such a molecular pre-analytic fixation tool, PAXgene-fixed paraffin-embedded (PFPE) biopsies, and their suitability for histomorphological BE diagnostics in comparison to FFPE. In a ring trial, 9 GI pathologists evaluated 116 digital BE slides of non-dysplastic BE (NDBE), low-grade dysplasia (LGD), high-grade dysplasia (HGD), and esophageal adenocarcinomas (EAC) using virtual microscopy. Overall quality, cytological and histomorphological parameters, dysplasia criteria, and diagnosis were analyzed. PFPE showed better preservation of nuclear details as chromatin and nucleoli, whereas overall quality and histomorphologic parameters as visibility of basal lamina, goblet cells, and presence of artifacts were scored as equal to FFPE. The interobserver reproducibility with regard to the diagnosis was best for NDBE and EAC (κF = 0.72–0.75) and poor for LGD and HGD (κF = 0.13–0.3) in both. In conclusion, our data suggest that PFPE allows equally confident histomorphological diagnosis of BE and EAC, introducing a novel tool for molecular analysis and parallel histomorphological evaluation.

Gut bacterial dysbiosis and instability is associated with the onset of complications and mortality in COVID-19

There is a growing debate about the involvement of the gut microbiome in COVID-19, although it is not conclusively understood whether the microbiome has an impact on COVID-19, or vice versa, especially as analysis of amplicon data in hospitalized patients requires sophisticated cohort recruitment and integration of clinical parameters. Here, we analyzed fecal and saliva samples from SARS-CoV-2 infected and post COVID-19 patients and controls considering multiple influencing factors during hospitalization. 16S rRNA gene sequencing was performed on fecal and saliva samples from 108 COVID-19 and 22 post COVID-19 patients, 20 pneumonia controls and 26 asymptomatic controls. Patients were recruited over the first and second corona wave in Germany and detailed clinical parameters were considered. Serial samples per individual allowed intra-individual analysis. We found the gut and oral microbiota to be altered depending on number and type of COVID-19-associated complications and disease severity. The occurrence of individual complications was correlated with low-risk (e.g., Faecalibacterium prausznitzii) and high-risk bacteria (e.g., Parabacteroides ssp.). We demonstrated that a stable gut bacterial composition was associated with a favorable disease progression. Based on gut microbial profiles, we identified a model to estimate mortality in COVID-19. Gut microbiota are associated with the occurrence of complications in COVID-19 and may thereby influencing disease severity. A stable gut microbial composition may contribute to a favorable disease progression and using bacterial signatures to estimate mortality could contribute to diagnostic approaches. Importantly, we highlight challenges in the analysis of microbial data in the context of hospitalization.

Mucosal-Associated Invariant T (MAIT) Cells Are Highly Activated and Functionally Impaired in COVID-19 Patients

Coronavirus disease 2019 (COVID-19), caused by infection with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), comprises mild courses of disease as well as progression to severe disease, characterised by lung and other organ failure. The immune system is considered to play a crucial role for the pathogenesis of COVID-19, although especially the contribution of innate-like T cells remains poorly understood. Here, we analysed the phenotype and function of mucosal-associated invariant T (MAIT) cells, innate-like T cells with potent antimicrobial effector function, in patients with mild and severe COVID-19 by multicolour flow cytometry. Our data indicate that MAIT cells are highly activated in patients with COVID-19, irrespective of the course of disease, and express high levels of proinflammatory cytokines such as IL-17A and TNFα ex vivo. Of note, expression of the activation marker HLA-DR positively correlated with SAPS II score, a measure of disease severity. Upon MAIT cell-specific in vitro stimulation, MAIT cells however failed to upregulate expression of the cytokines IL-17A and TNFα, as well as cytolytic proteins, that is, granzyme B and perforin. Thus, our data point towards an altered cytokine expression profile alongside an impaired antibacterial and antiviral function of MAIT cells in COVID-19 and thereby contribute to the understanding of COVID-19 immunopathogenesis.

Epidemiologic Risk Factors in a Comparison of a Barrett Esophagus Registry (BarrettNET) and a Case-Control Population in Germany

Endoscopic screening for Barrett's esophagus as the major precursor lesion for esophageal adenocarcinoma is mostly offered to patients with symptoms of gastroesophageal reflux disease (GERD). However, other epidemiologic risk factors might affect the development of Barrett's esophagus and esophageal adenocarcinoma. Therefore, efforts to improve the efficiency of screening to find the Barrett's esophagus population "at risk" compared with the normal population are needed. In a cross-sectional analysis, we compared 587 patients with Barrett's esophagus from the multicenter German BarrettNET registry to 1976 healthy subjects from the population-based German KORA cohort, with and without GERD symptoms. Data on demographic and lifestyle factors, including age, gender, smoking, alcohol consumption, body mass index, physical activity, and symptoms were collected in a standardized epidemiologic survey. Increased age, male gender, smoking, heavy alcohol consumption, low physical activity, low health status, and GERD symptoms were significantly associated with Barrett's esophagus. Surprisingly, among patients stratified for GERD symptoms, these associations did not change. Demographic, lifestyle, and clinical factors as well as GERD symptoms were associated with Barrett's esophagus development in Germany, suggesting that a combination of risk factors could be useful in developing individualized screening efforts for patients with Barrett's esophagus and GERD in Germany.

BarrettNET-a prospective registry for risk estimation of patients with Barrett's esophagus to progress to adenocarcinoma

Risk stratification in patients with Barrett's esophagus (BE) to prevent the development of esophageal adenocarcinoma (EAC) is an unsolved task. The incidence of EAC and BE is increasing and patients are still at unknown risk. BarrettNET is an ongoing multicenter prospective cohort study initiated to identify and validate molecular and clinical biomarkers that allow a more personalized surveillance strategy for patients with BE. For BarrettNET participants are recruited in 20 study centers throughout Germany, to be followed for progression to dysplasia (low-grade dysplasia or high-grade dysplasia) or EAC for >10 years. The study instruments comprise self-administered epidemiological information (containing data on demographics, lifestyle factors, and health), as well as biological specimens, i.e., blood-based samples, esophageal tissue biopsies, and feces and saliva samples. In follow-up visits according to the individual surveillance plan of the participants, sample collection is repeated. The standardized collection and processing of the specimen guarantee the highest sample quality. Via a mobile accessible database, the documentation of inclusion, epidemiological data, and pathological disease status are recorded subsequently. Currently the BarrettNET registry includes 560 participants (23.1% women and 76.9% men, aged 22-92 years) with a median follow-up of 951 days. Both the design and the size of BarrettNET offer the advantage of answering research questions regarding potential causes of disease progression from BE to EAC. Here all the integrated methods and materials of BarrettNET are presented and reviewed to introduce this valuable German registry.

Breastfeeding and vitamin D supplementation reduce the risk of Kawasaki disease in a German population-based case-control study

Background

In Kawasaki disease (KD), a vasculitis of unknown etiology, the most serious complication is the development of coronary artery aneurysm (CAA). To date, the exact pathomechanism of KD is unknown. Both environmental and genetic factors seem to be associated with the development of the disease.

Methods

Data on KD patients recruited from the population-based German Pediatric Surveillance Study during 2012–2014 were used to evaluate the impact of various factors from the perinatal and infancy period on the development of KD. The study design was a matched case-control study with respect to age, sex and place of residence (n = 308 KD cases, n = 326 controls). All KD patients were individually re-evaluated; all fulfilled the international diagnostic KD criteria. A standardized questionnaire was used to review breastfeeding practices, vitamin D supplementation and birth characteristics. Logistic regression analyses were performed to obtain odds ratios (OR) for various risk factors among the case-control pairs. Simple measures of association were used to assess the impact of these factors on the clinical course.

Results

There was no difference in lengths of gestation, birth weight or parturition between KD patients and controls, but independently from each other vitamin D supplementation and breastfeeding were negatively associated with KD, even when adjusted for age, place of residence and sex. The duration of vitamin D was significantly shorter among children with KD than among children without KD (p = 0.039, OR = 0.964, 95% CI: 0.931–0.998), as was the duration of breastfeeding (p = 0.013, OR = 0.471, 95% CI: 0.260–0.853). Comparing KD patients with and without breastfeeding and/or vitamin D supplementation, there were no differences regarding developing CAA, being refractory to intravenous immunoglobulin treatment, age at onset of the disease and levels of inflammatory laboratory values.

Conclusion

Our findings indicate breastfeeding and vitamin D supplementation to have protective effects in association with KD in our study population; however, these seem not to influence the natural course of the disease. Although the overall effects were relatively small, they nevertheless underline the overall benefit of both interventions.

Trial registration

Clinical Trial Registration: German clinical trial registration, http://apps.who.int/trialsearch/Trial2.aspx?TrialID=DRKS00010071. Date of registration was 26. February 2016. The trial was registered retrospectively.

Electronic supplementary material

The online version of this article (10.1186/s12887-019-1438-2) contains supplementary material, which is available to authorized users.

Complicated grief in patients with unipolar depression

BACKGROUND

The loss of a close family member (e.g. child or spouse) has been shown to be one of the most stressful life-events increasing the risk of affective disorders. In the present study, we investigated for the first time the frequency of complicated grief in psychiatric inpatients with unipolar depression. Further, the study was aimed to identify characteristics predicting a complicated grief reaction in depressed patients.

METHODS

In a sample of 73 DSM-IV diagnosed unipolar affective disordered inpatients grief, depression, anxiety and psychological stress reaction were assessed.

RESULTS

A high prevalence of loss and impairing complicated grief was found in this sample of unipolar depressed patients. Depressed patients with complicated grief were more severely depressed than depressed patients without complicated grief reactions. Higher traumatic stress and close family membership of the lost person were associated with higher severity of grief.

CONCLUSIONS

Comorbid complicated grief appears to contribute to greater severity and poorer functioning in unipolar depressed patients and should be specifically addressed in psychotherapeutic treatment.

Association of MAO-A variant with complicated grief in major depression

BACKGROUND/AIMS

It has been suggested that monoamine oxidase A (MAO-A) activity is involved in the pathogenesis of major depression. Bereavement-related complicated grief significantly increases the risk of major depression and has been shown to be influenced by serotonergic tonus, possibly conferred by MAO-A activity. Complicated grief--whose inclusion in DSM-V as a separate mental disorder is under discussion--has been shown to be a distinct syndrome with symptoms not seen in depression. Therefore, in the present study, genetic variation in the MAO-A gene was investigated for its influence on complicated grief in major depression.

METHODS

Sixty-six unrelated Caucasian patients (41 female, 25 male) with major depression and a history of bereavement were evaluated for complicated grief using the Inventory of Complicated Grief (ICG), the posttraumatic stress reaction after the loss by means of the Impact of Event Scale (IES-R) and further psychopathological measures. Patients were additionally genotyped for the functional variable number tandem repeat (VNTR) in the promoter region of the MAO-A gene.

RESULTS

The more active longer allele of the MAO-A VNTR was significantly associated with complicated grief in the female subgroup of patients (chi(2) = 9.471, p = 0.002, OR = 9.208, 95% CI 2.129-38.899, Bonferroni-corrected p = 0.012), whereas there was no such effect in male patients. Higher posttraumatic stress reaction was only nominally associated with the more active longer allele of the MAO-A VNTR in the female subgroup of patients (genotypes: chi(2) = 5.939, p = 0.015, OR = 5.333, 95% CI 1.366-20.557, Bonferroni-corrected p = 0.087). No significant associations of MAO-A VNTR with the severity of depressive symptoms (Beck Depression Inventory), anxiety symptoms (Spielberger State-Trait Anxiety Inventory), general mental health (Brief Symptom Inventory), or perceived social support (F-SozU) were found (all p > 0.10).

CONCLUSION

The present pilot study for the first time suggests a gender-specific contribution of the more active MAO-A VNTR variant to an increased vulnerability for complicated grief as a potential intermediate phenotype of major depression.

A carboxypeptidase inhibitor from the medical leech Hirudo medicinalis. Isolation, sequence analysis, cDNA cloning, recombinant expression, and characterization

A novel metallocarboxypeptidase inhibitor was isolated from the medical leech Hirudo medicinalis. Amino acid sequence analysis provided a nearly complete primary structure. which was subsequently verified and completed by cDNA cloning using reverse transcriptase-polymerase chain reaction/rapid amplification of cDNA end techniques. The inhibitor, called LCI (leech carboxypeptidase inhibitor), is a cysteine-rich polypeptide composed of 66 amino acid residues. It does not show sequence similarity to any other protein except at its C-terminal end. In this region, the inhibitor shares the amino acid sequence -Thr-Cys-X-Pro-Tyr-Val-X with Solanacea carboxypeptidase inhibitors, suggesting a similar mechanism of inhibition where the C-terminal tail of the inhibitor interacts with the active center of metallocarboxypeptidases in a substrate-like manner. This hypothesis is supported by the hydrolytic release of the C-terminal glutamic acid residue of LCI after binding to the enzyme. Heterologous overexpression of LCI in Escherichia coli, either into the medium or as an intracellular thioredoxin fusion protein, yields a protein with full inhibitory activity. Both in the natural and recombinant forms, LCI is a tightly binding, competitive inhibitor of different types of pancreatic-like carboxypeptidases, with equilibrium dissociation constants Ki of 0.2-0.4 x 10(-9) M for the complexes with the pancreatic enzymes A1, A2, and B and plasma carboxypeptidase B. Circular dichroism and nuclear magnetic resonance spectroscopy analysis indicate that recombinant LCI is a compactly folded globular protein, stable to a wide range of pH and denaturing conditions.

Searching for the best weight reduction operation

At the University of Minnesota under the supervision of one staff surgeon both jejunoileal bypass (JIB) and gastric bypass (GIB) operations have been performed for weight reduction in morbidly obese individuals. During the last 14 years 727 patients underwent end-to-end (40 to 4 cm) JIB and more than 570 patients underwent GIB. This report is based on a comparison of 205 JIBs performed between July 1975 and July 1979, 106 Alden-loop type GIBs (GIB-loop) performed between July 1975 and July 1979, 53 loop GIBs with enteroenterostomies between the limbs of the loop (GIB-EE) performed between May 1980 and May 1981, and 57 Roux-en-Y GIBs (GIB-Roux) performed between May 1981 and May 1982. Adequate weight loss occurred in 80% of the patients who returned for follow-up in all groups. The percentage of excess body weight loss was similar for the first year (65% for JIB, 62% for GIB-loop, 69% for GIB-EE, and 71% for GIB-Roux). The operative mortality and the immediate morbidity rates were uniformly low. The long-term complications for JIB were 37.7% arthralgia, 7.1% oxalate urolithiasis, 5.6% incisional hernia, and 1.4% liver failure. The complications for GIB-loop were 10.2% nausea/vomiting, 1.9% bile reflux gastritis, and 2.8% anastomotic problems; for GIB-EE 23% nausea/vomiting, 7% bile gastritis, 4.6% incisional hernia, and 3.7% anastomotic problems; and for GIB-Roux 16% nausea/vomiting and 1.7% anastomotic problems. The anastomotic problems consisted of afferent loop obstructions and stomal stenosis; there were no leaks. At 1 year plasma cholesterol reduction for JIB averaged 42% (p less than 0.001), GIB-loop 14% (p less than 0.001), GIB-EE 7% (NS), and GIB-Roux 17% (p less than 0.001). One year after operation 49% of 88 JIB patients showed progression of liver disease on sequential biopsy specimens and 20% improvement. In the 78 GIB patients with sequential biopsies, liver disease progressed in 8% and improved in 65%. In summary, comparable therapeutic weight reduction occurred with all the assessed procedures; however, the GIB-Roux was associated with far fewer serious long-term complications. At this time the GIB-Roux procedure is the weight reduction operation we recommend.

Comparisons between jejunoileal and gastric bypass operations for morbid obesity

At the University of Minnesota, under the supervision of one staff surgeon, both the jejunoileal bypass (JIB) and gastric bypass (GIB) operations have been done for weight reduction in morbidly obese individuals. Over the past 11 years, end-to-end (40 to 4 cm) JIB performed for 727 patients. In addition, antecolic GIB was performed for 364 patients over the past 6 years. This report is based primarily on a comparison of 205 JIB and 106 GIB patients with surgery between July 1975 and July 1979. Adequate weight loss was seen in 75% of each group. The percentage of excess body weight loss was similar for the first year (65% for JIB and 62% for GIB); however, the JIB patients started at 214% of ideal weight and GIB patients at 197% of ideal weight. The operative mortality rate for either operation was well below 1%, and the immediate operative morbidity rate was low and only rarely delayed discharge from the hospital. The long-term complications for JIB were 37.7% arthralgia or arthritis, 7.1% oxalate urolithiasis, 5.6 incisional hernia, and 1.4% liver failure; complications of GIB were 10.2% nausea and/or vomiting, 1.9% reflux esophagitis, and 2.8% anastomotic problems. At 1 year, plasma cholesterol reductions for JIB patients averaged 42% (P less than 0.001), whereas for the GIB patients it ws only 14% (P less than 0.001). At 1 year after operation, 49% of 88 JIB patients showed progression of liver disease on sequential biopsies, with 31% unchanged and 20% improved. In 43 GIB patients, the biopsies showed improvement in 58%, an unchanged status in 30%, and worsening in 12%. The levels of serum glutamic oxaloacetic transaminase and alkaline phosphatase increased after JIB and eventually returned to normal, while GIB patients had only minor fluctuations of liver function tests. Comparable therapeutic weight results occurred with JIB and GIB; however, the GIB was associated with far fewer serious long-term complications and the JIB with a far greater cholesterol lowering. A percentage of the GIB patients showed progression of liver disease at 1 year after bypass.

Selection of respiratory mutants of Neurospora crassa

A method is described that permits the isolation of mutants that are defective in mitochondrial respiration. The techniques of inositol-less death and overlay with 2,3,5-triphenyl-2H-tetrazolium chloride are utilized to select for mutant colonies. Colonies that survive inositol-less death and fail to reduce the tetrazolium dye are then tested polarographically for cyanide-sensitive respiration. A preliminary characterization of three mutants obtained by this method is presented. The mutants have been characterized by their cyanide-sensitive respiration rate, growth rate, the state III respiration rate of isolated mitochondria, inhibition of the respiration of isolated mitochondria by cyanide and antimycin A, and cytochrome spectra. All of the mutants described differ from the parent strain in some of these aspects.