Profiling native pulmonary basement membrane stiffness using atomic force microscopy

Mammalian cells sense and react to the mechanics of their immediate microenvironment. Therefore, the characterization of the biomechanical properties of tissues with high spatial resolution provides valuable insights into a broad variety of developmental, homeostatic and pathological processes within living organisms. The biomechanical properties of the basement membrane (BM), an extracellular matrix (ECM) substructure measuring only ∼100-400 nm across, are, among other things, pivotal to tumor progression and metastasis formation. Although the precise assignment of the Young's modulus E of such a thin ECM substructure especially in between two cell layers is still challenging, biomechanical data of the BM can provide information of eminent diagnostic potential. Here we present a detailed protocol to quantify the elastic modulus of the BM in murine and human lung tissue, which is one of the major organs prone to metastasis. This protocol describes a streamlined workflow to determine the Young's modulus E of the BM between the endothelial and epithelial cell layers shaping the alveolar wall in lung tissues using atomic force microscopy (AFM). Our step-by-step protocol provides instructions for murine and human lung tissue extraction, inflation of these tissues with cryogenic cutting medium, freezing and cryosectioning of the tissue samples, and AFM force-map recording. In addition, it guides the reader through a semi-automatic data analysis procedure to identify the pulmonary BM and extract its Young's modulus E using an in-house tailored user-friendly AFM data analysis software, the Center for Applied Tissue Engineering and Regenerative Medicine processing toolbox, which enables automatic loading of the recorded force maps, conversion of the force versus piezo-extension curves to force versus indentation curves, calculation of Young's moduli and generation of Young's modulus maps, where the pulmonary BM can be identified using a semi-automatic spatial filtering tool. The entire protocol takes 1-2 d.

Assisted reproductive technology (ART) is not an independent risk factor for breech presentation among singleton term births in Vienna, Austria

Assisted reproductive technologies (ARTs) such as in vitro fertilisation (IVF) and intracytoplasmic sperm injection (ICSI) are still discussed critically, as there is no consensus on whether these treatments could be the cause of risk factors for obstetric problems such as breech presentation. The aim of this study was to test the association between ART and breech presentation among 11920 singleton term births taking place in Vienna from 2010 to 2020. In this single-centre medical record-based study, data concerning the conception mode (spontaneous versus IVF or ICSI), child presentation, birth mode, newborn sex and size as well as age, height, weight, and reproductive history of the mother were included. Three hundred twenty-six newborns (2.7%) were conceived by IVF or ICSI, and 527 newborns (4.4%) were delivered in breech presentation. Breech presentation occurred in 7.6% of IVF/ICSI children but only in 4.3% of spontaneously conceived children (P = 0.019). ART increased the crude risk of breech presentation significantly (OR = 1.67; 95% CI 1.71 - 2.38). After adjusting for maternal age, height, number of previous births, smoking, and newborn sex, however, ART had no longer a significant impact on the risk of breech presentation. In contrast, breech presentation was significantly associated with higher maternal age as well as a lower number of previous births, but not with ART. This study shows that the adverse outcomes of IVF and ICSI pregnancies may not be due to the ART treatment alone but might also be due to the mostly higher age and lower parity of the mothers using ART.

Indium tin oxide ultrafast laser lift-off ablation mechanisms and damage minimization

We draw comparisons between the ablation and damage mechanisms that occur for both film and substrate irradiation using atomic force microscopy, scanning electron microscopy, and pump-probe reflectometry. For substrate irradiation, energy absorbed at the film-substrate interface creates a confined energy situation, resulting in a photomechanical lift-off. A partial ablation at the edges of the ablated zone formed the burr and was reduced in height by minimizing the area subject to the partial ablation threshold fluence. Substrate damage is understood to arise from free electron diffusion from indium tin oxide and subsequent laser heating. We establish a process window for substrate irradiation in a single-pulse ablation regime between approximately two to three times the ablation threshold of 0.18 J/cm2, validating the process window seen in literature and provide a crucial understanding for the ablation mechanisms of transparent conductive films.

Novel α-glycosyl compounds from glycosylation of rubusoside

In this work we investigated mixtures from α-glycosylation of rubusoside with cyclodextrin glycosyltransferases. In addition to the previously known α-1,4 glycosylated derivatives, nine new compounds with rare α-1,3-glycosidic bonds were identified based on nuclear magnetic resonance spectroscopy and mass spectrometric analysis. Furthermore, sensory properties of monoglycosylated rubusoside derivatives were investigated and compared to previously described monoglycosylated compounds. Additionally, digestion with α-amylase from human saliva was investigated for different glycosylated rubusoside derivatives.

COVID-19 Lockdown Periods in 2020: Good Maintenance of Metabolic Control in Adults with Type 1 and Type 2 Diabetes

During the COVID-19 pandemic, there were increased concerns about glycemic control in patients with diabetes. Therefore, we aimed to assess changes in diabetes management during the COVID-19 lockdown for patients with type 1 or type 2 diabetes mellitus (T1DM, T2DM) in Germany. We included data from 24,623 patients (age>18 years) with T1DM (N=6,975) or T2DM (N=17,648) with documented data in 2019 and 2020 from the multicenter Diabetes-Prospective Follow-up registry (DPV). We conducted a groupwise comparison of identical patients in 2019 and 2020 for different time periods of pandemia. Pairwise differences of continuous parameters of treatment modalities and metabolic outcome between 2019 and 2020 were adjusted for seasonality, age, and diabetes duration. We presented these outcomes as adjusted medians with 95% confidence intervals. Rates were compared using negative-binomial models, dichotomous outcomes were compared using logistic models. Models were additionally adjusted for age and diabetes duration. These outcomes were presented as least-square means with 95% confidence intervals, p-values of<.05 were considered significant.In participants with T1DM, CGI (combined glucose indicator) increased only by 0.11-0.12% in all time periods of 2020 compared to 2019 (all p<0.001) while BMI decreased slightly by -(0.09-0.10) kg/m² (p<0.0001). In participants with T2DM, HbA1c increased by 0.12%, while BMI decreased slightly by -(0.05-0.06) kg/m² (p<0.0001).During the COVID-19 lockdown period, patients with T1DM and T2DM experienced only clinically insignificant changes in glucose control or body weight. Despite lockdown restrictions, patients were able to maintain metabolic control.

Precision 3D-Printed Cell Scaffolds Mimicking Native Tissue Composition and Mechanics

Cellular dynamics are modeled by the 3D architecture and mechanics of the extracellular matrix (ECM) and vice versa. These bidirectional cell-ECM interactions are the basis for all vital tissues, many of which have been investigated in 2D environments over the last decades. Experimental approaches to mimic in vivo cell niches in 3D with the highest biological conformity and resolution can enable new insights into these cell-ECM interactions including proliferation, differentiation, migration, and invasion assays. Here, two-photon stereolithography is adopted to print up to mm-sized high-precision 3D cell scaffolds at micrometer resolution with defined mechanical properties from protein-based resins, such as bovine serum albumin or gelatin methacryloyl. By modifying the manufacturing process including two-pass printing or post-print crosslinking, high precision scaffolds with varying Young's moduli ranging from 7-300 kPa are printed and quantified through atomic force microscopy. The impact of varying scaffold topographies on the dynamics of colonizing cells is observed using mouse myoblast cells and a 3D-lung microtissue replica colonized with primary human lung fibroblast. This approach will allow for a systematic investigation of single-cell and tissue dynamics in response to defined mechanical and bio-molecular cues and is ultimately scalable to full organs.

Slow motions in A·T rich DNA sequence

In free B-DNA, slow (microsecond-to-millisecond) motions that involve equilibrium between Watson-Crick (WC) and Hoogsteen (HG) base-pairing expand the DNA dynamic repertoire that could mediate DNA-protein assemblies. R_1ρ relaxation dispersion NMR methods are powerful tools to capture such slow conformational exchanges in solution using ¹³C/¹⁵ N labelled DNA. Here, these approaches were applied to a dodecamer containing a TTAAA element that was assumed to facilitate nucleosome formation. NMR data and inferred exchange parameters assign HG base pairs as the minor, transient conformers specifically observed in three successive A·T base pairs forming the TAA·TTA segment. The abundance of these HG A·T base pairs can be up to 1.2% which is high compared to what has previously been observed. Data analyses support a scenario in which the three adenines undergo non-simultaneous motions despite their spatial proximity, thus optimising the probability of having one HG base pair in the TAA·TTA segment. Finally, revisiting previous NMR data on H2 resonance linewidths on the basis of our results promotes the idea of there being a special propensity of A·T base pairs in TAA·TTA tracts to adopt HG pairing. In summary, this study provides an example of a DNA functional element submitted to slow conformational exchange. More generally, it strengthens the importance of the role of the DNA sequence in modulating its dynamics, over a nano- to milli-second time scale.

Early Detection of Cartilage Degeneration: A Comparison of Histology, Fiber Bragg Grating-Based Micro-Indentation, and Atomic Force Microscopy-Based Nano-Indentation

We have determined the sensitivity and detection limit of a new fiber Bragg grating (FBG)-based optoelectronic micro-indenter for biomechanical testing of cartilage and compared the results to indentation-type atomic force microscopy (IT-AFM) and histological staining. As test samples, we used bovine articular cartilage, which was enzymatically degraded ex vivo for five minutes using different concentrations of collagenase (5, 50, 100 and 500 µg/mL) to mimic moderate extracellular matrix deterioration seen in early-stage osteoarthritis (OA). Picrosirius Red staining and polarization microscopy demonstrated gradual, concentration-dependent disorganization of the collagen fibrillar network in the superficial zone of the explants. Osteoarthritis Research Society International (OARSI) grading of histopathological changes did not discriminate between undigested and enzymatically degraded explants. IT-AFM was the most sensitive method for detecting minute changes in cartilage biomechanics induced by the lowest collagenase concentration, however, it did not distinguish different levels of cartilage degeneration for collagenase concentrations higher than 5 µg/mL. The FBG micro-indenter provided a better and more precise assessment of the level of cartilage degeneration than the OARSI histological grading system but it was less sensitive at detecting mechanical changes than IT-AFM. The FBG-sensor allowed us to observe differences in cartilage biomechanics for collagenase concentrations of 100 and 500 µg/mL. Our results confirm that the FBG sensor is capable of detecting small changes in articular cartilage stiffness, which may be associated with initial cartilage degeneration caused by early OA.

SkinDot: A modified full-skin transplantation technique

Existing epidermal transplantation procedures applied in burn surgery or wound treatment, such as mesh grafting or the Meek method, do not lead to a restoration of all the skin layers. Dermal skin layers are indispensable in ensuring the quality and function of the transplanted skin as a frictional surface and a carrier of skin appendages such as hair, sweat glands, and sebaceous glands, as well as nerve receptors for detecting pressure, vibration, and temperature. Because of the restricted skin surface area that can be provided by the donor, full-skin transplants cannot be transplanted over a large area. Cultured skin procedures, based on skin cells cultivated in a laboratory, have not yet reached a stage of development where a complex full epidermal transplantation is possible. In particular, the introduction of skin appendages with a functional cell-to-cell communication has not been observed thus far in cultivated skin. Based on the Reverdin transplantation method, in which concave skin islands with epidermal and dermal parts are transplanted, Davis in 1910 described the transplantation of multiple 2-5 mm sized full-skin islands as a new method for the treatment of skin lesions. Further modifying this 100-year-old procedure, we developed a miniaturization and automation of the Davis transplantation method that started in 2011 and called it "SkinDot". In the following article we describe the effectiveness of the full-skin island transplant procedure in two patients. The transplantation of single 2-3 mm full-skin islands results in a full-skin equivalent without any limits on donor area and with a reduced donor morbidity.

An in vitro feasibility investigation considering primary human melanocytes for spray- grafting of freshly isolated autologous skin cells for burn treatment and a clinical case report

A skin cell-spray grafting technique that enables the on-site application of freshly isolated autologous single cell suspensions was already applied in many cases on caucasian patients with low skin coloration. Our project hypothesis is that these suspensions contain keratinocytes and vital melanocytes, that are of particular interest for the treatment of patients of darker skin color. To test this, we applied an in vitro model, wherein the feasibility of i) isolating and ii) spraying of freshly isolated autologous melanocyte-keratinocyte cell suspensions was investigated. Primary human epidermal keratinocytes (HEKs) and melanocytes (MCs) were isolated from skin biopsies (n=8). Biochemical parameter, cell counts, cell morphology, growth behavior and immunofluorescence results were compared in two groups using MC cultures and co-cultures of MCs with HEKs. Case information on using the method clinically with one patient is included. The sprayed mixed cell suspensions proliferated in all groups without measurable loss of viability, and MCs exhibited a regular cell morphology in monoculture up to passage 4°. The sprayed MCs and HEKs demonstrated in vitro glucose and lactate metabolism that was comparable to the pipetted controls. In co-culture, well distributed CK14+ HEKs and NKI/beteb+ MCs could be demonstrated, which interacted in the in vitro model. The ratio of HEKs : MCs in our primary cultures were microscopically counted (n=8 each) as mean +/- SD 1,211,000 (+/- 574,343) HEK : 99,625 (+/- 59,025) MC; i.e., a ratio of approx. 12 : 1. Using the isolation method clinically for a patient with dark skin coloration after suffering severe second-degree burns shows a satisfying re-pigmentation of the resulting wound post healing. Freshly isolated spray-on melanocyte/keratinocyte suspensions provide for a considerable amount of viable HEKs and MCs. Using MCs in spray-grafting suspensions could represent a promising approach for treating severe partial-thickness burns and innovative therapy developments that also aim to address cosmetic aspects.

Pilus-1 Backbone Protein RrgB of Streptococcus pneumoniae Binds Collagen I in a Force-Dependent Way

Attachment to host tissue is a prerequisite for successful host colonization and invasion of pathogens. Many pathogenic bacteria use surface appendices, called pili, to bind and firmly attach to host tissue surfaces. Although it has been speculated that the laterally positioned D3 domain of the pilus-1 backbone protein RrgB of Streptococcus pneumoniae may promote bacterial-host interaction, via adhesion to extracellular matrix molecules, such as collagen, earlier studies showed no affinity of RrgB to collagen I. Using atomic force microscopy-based single molecule force spectroscopy combined with lateral force microscopy, we show that under mechanical load, RrgB in fact binds to human collagen I in a force-dependent manner. We observe exceptionally strong interactions, with interaction forces reaching as much as 1500 pN, and we show that high force loading and shearing rates enhance and further strengthen the interaction. In addition, the affinity of RrgB to collagen I under mechanical load not only depends on the orientation of the D3 domain but also on the orientation of the collagen fibrils, relative to the pulling direction. Both exceptionally high binding forces and force-induced bond strengthening resemble the behavior of so-called catch bonds, which have recently been observed in bacterial adhesins, but have not been reported for multimeric backbone subunits of virulence related pili.

Aggrecan Hypomorphism Compromises Articular Cartilage Biomechanical Properties and Is Associated with Increased Incidence of Spontaneous Osteoarthritis

The gene encoding the proteoglycan aggrecan (Agc1) is abundantly expressed in cartilage during development and adulthood, and the loss or diminished deposition of the protein results in a wide range of skeletal malformations. Furthermore, aggrecan degradation is a hallmark of cartilage degeneration occurring in osteoarthritis. In the present study, we investigated the consequences of a partial loss of aggrecan in the postnatal skeleton and in the articular cartilage of adult mice. We took advantage of the previously described Agc1^{tm(IRES-CreERT2)} mouse line, which allows for conditional and timely-regulated deletion of floxed, cartilage-expressed genes. As previously reported, the introduction of the CreER^T2 cassette in the 3’UTR causes a disruption of the normal expression of Agc1 resulting in a hypomorphic deposition of the protein. In homozygous mice, we observed a dwarf phenotype, which persisted throughout adulthood supporting the evidence that reduced aggrecan amount impairs skeletal growth. Homozygous mice exhibited reduced proteoglycan staining of the articular cartilage at 6 and 12 months of age, increased stiffening of the extracellular matrix at six months, and developed severe cartilage erosion by 12 months. The osteoarthritis in the hypomorph mice was not accompanied by increased expression of catabolic enzymes and matrix degradation neoepitopes. These findings suggest that the degeneration found in homozygous mice is likely due to the compromised mechanical properties of the cartilage tissue upon aggrecan reduction.

Abstract P1-12-19: Quality of life of patients with pregnancy- associated breast cancer

Background: Breast cancer (BC) is the most common cancer diagnosed during pregnancy and occurs between one in 3000 to one in 10 000 pregnancies. The first international guidelines for the diagnosis and therapy of pregnancy associated BC (PABC) has been developed in 2003. The 5 year survival rate is similar to the non-pregnant women with the same stage of disease. In contrast to the data about the oncological outcome of patients with PABC, the literature about quality of life (QoL) of those patients is lacking. The aim of the study was to investigate the QoL of patients with PABC.

Materials and methods: Patients with PABC diagnosed and treated at our department in the period between 2000 and 2016 were included in the study. Clinical and demographic data were collected from the data base. The QOL was assessed using the EORTC QLQ-C30, the EORTC QLQ-BR 45 and the EORTC SHQ-22. The QoL results were compared with reference data (EORTC Reference Values) of BC patients. Statistical analysis was performed using descriptive statistics and t-test to test the significance.

Results: In the analysed period, twenty-one patients with PABC were found. In 16 patients BC had been diagnosed during the pregnancy and in 5 patients during the first year after delivery. Mean age at the time of diagnosis was 34.24 (SD±3.3), mean pregnancy week 21.14 (SD±10.28), and 8 months (SD±5.0) for patients with the diagnosis in the first year after the delivery. All patients underwent surgery, as well as chemotherapy. In addition, 10 patients received hormonal therapy and 12 irradiation.

16 patients lived at the time of the QoL assessment and received the QoL questionnaire per mail. After the mean follow up of 5.2 years, there were no statistically significant differences in EORTC QLQ C30 scales between our population and reference data except for constipation which a better score in our population. Clinical relevant differences were found in scales: physical functioning, role functioning and symptom dyspnea with the better score in our population. Our patients reported clinical relevant more financial difficulties. In the disease specific questionnaire EORTC BC 45, patients with PABC showed statistically significantly worse score in the following scales: body image, upset by hair loss, side effects of the systemic therapy and future perspective. 40% of the patients had a decreased libido and 37% of patients reported that therapy negatively impaired sexual activity. 25% of patients reported that they fill less feminine because of the disease.

Conclusion: The results revealed that QoL in patients with PABC is more impaired compared to the overall QoL reference data of BC patients. Despite the small number of patients, the results indicate that PABC patients are a vulnerable group, especially regarding outer appearance (body image, upset by hair loss, fill les feminine). The QLQ BR 45 showed more sensitivity to assess the impact on QoL of these patients than EORTC QLQ C30 and underlines the necessity to use disease-specific questionnaires in specific patient populations.

Citation Format: Bjelic-Radisic V, Hartmann B, Reisinger J, Trapp E, Benedicic C, Klaritsch P, Dunst E, Brcic I, Tamussino K. Quality of life of patients with pregnancy- associated breast cancer [abstract]. In: Proceedings of the 2018 San Antonio Breast Cancer Symposium; 2018 Dec 4-8; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2019;79(4 Suppl):Abstract nr P1-12-19.

Embryoscopy and karyotype findings of repeated miscarriages in recurrent pregnancy loss and spontaneous pregnancy loss

PURPOSE

The aim of the study was to assess cytogenetic and embryoscopic characteristics in subsequent miscarriages of spontaneous pregnancy losses (SPL) and recurrent pregnancy losses (RPL).

METHODS

A retrospective cohort of 75 women was affected by repeated pregnancy loss. Of those, 34 had SPL, 24 primary RPL, and 17 secondary RPL. Ploidy status and morphology was analyzed by transcervical embryoscopic examination of the embryo and cytogenetic analysis of the chorionic villi in subsequent miscarriages.

RESULTS

Similar rates of recurrent ploidy status were observed between first and second miscarriage in SPL and RPL (82.4% recurrent ploidy status in SPL, p > 0.999; 73% recurrent ploidy status in RPL, p = 0.227). No difference was found regarding recurrent abnormal morphology between SPL and RPL (p = 0.092). However, secondary RPL resulted significantly more often in recurrent abnormal morphology compared to primary RPL (p = 0.004).

CONCLUSIONS

High rates of recurrent normal/abnormal karyotypes were observed in all groups with a majority of embryos presenting with recurrent abnormal morphology. Secondary RPL presented significantly more often with recurrent abnormal morphology compared to primary RPL. These findings offer prognostic information for the affected patient and might impact treatment choice.

Ghrelin secretion in humans - a role for the vagus nerve?

BACKGROUND

Ghrelin, an orexigenic peptide, is secreted from endocrine cells in the gastric mucosa. Circulating levels rise in the preprandial phase, suggesting an anticipatory or cephalic phase of release, and decline in the postprandial phase, suggesting either the loss of a stimulatory factor or inhibition by factors released when nutrients enter the intestine. We hypothesized that vagal signals are not required for the (i) preprandial increase or (ii) postprandial suppression of ghrelin levels. Further, we wanted to investigate the hypothesis that (iii) glucagon-like peptide-1 might be implicated in the postprandial decline in ghrelin levels.

METHODS

We measured ghrelin levels in plasma from sham-feeding and meal studies carried out in vagotomized individuals and controls, and from a GLP-1 infusion study carried out in fasting healthy young individuals.

KEY RESULTS

We find that (i) ghrelin secretion is unchanged during indirect vagal stimulation as elicited by modified sham-feeding in vagotomized individuals and matched controls, (ii) ghrelin secretion is similarly suppressed after meal ingestion in vagotomized individuals and controls, and (iii) infusion of GLP-1 does not lower ghrelin levels.

CONCLUSIONS & INFERENCES

We conclude that for postprandial suppression of circulating ghrelin levels, a circulating factor (but not GLP-1) or short (duodeno-gastric) reflexes seem to be implicated.

Sacrificial-layer free transfer of mammalian cells using near infrared femtosecond laser pulses

Laser-induced cell transfer has been developed in recent years for the flexible and gentle printing of cells. Because of the high transfer rates and the superior cell survival rates, this technique has great potential for tissue engineering applications. However, the fact that material from an inorganic sacrificial layer, which is required for laser energy absorption, is usually transferred to the printed target structure, constitutes a major drawback of laser based cell printing. Therefore alternative approaches using deep UV laser sources and protein based acceptor films for energy absorption, have been introduced. Nevertheless, deep UV radiation can introduce DNA double strand breaks, thereby imposing the risk of carcinogenesis. Here we present a method for the laser-induced transfer of hydrogels and mammalian cells, which neither requires any sacrificial material for energy absorption, nor the use of UV lasers. Instead, we focus a near infrared femtosecond (fs) laser pulse (λ = 1030 nm, 450 fs) directly underneath a thin cell layer, suspended on top of a hydrogel reservoir, to induce a rapidly expanding cavitation bubble in the gel, which generates a jet of material, transferring cells and hydrogel from the gel/cell reservoir to an acceptor stage. By controlling laser pulse energy, well-defined cell-laden droplets can be transferred with high spatial resolution. The transferred human (SCP1) and murine (B16F1) cells show high survival rates, and good cell viability. Time laps microscopy reveals unaffected cell behavior including normal cell proliferation.

Nutrient re-routing and altered gut-islet cell crosstalk may explain early relief of severe postprandial hypoglycaemia after reversal of Roux-en-Y gastric bypass

BACKGROUND

Roux-en-Y gastric bypass is associated with an increased risk of postprandial hyperinsulinaemic hypoglycaemia, but the underlying pathophysiology remains poorly understood. We therefore examined the effect of re-routing of nutrient delivery on gut-islet cell crosstalk in a person with severe postprandial hypoglycaemia after Roux-en-Y gastric bypass.

CASE REPORT

A person with severe postprandial hypoglycaemia, who underwent surgical reversal of Roux-en-Y gastric bypass, was studied before reversal and at 2 weeks and 3 months after reversal surgery using liquid mixed meal tests and hyperinsulinaemic-euglycaemic clamps. The nadir of postprandial plasma glucose rose from 2.8 mmol/l to 4.1 mmol/l at 2 weeks and to 4.4 mmol/l at 3 months after reversal. Concomitant insulin- and glucagon-like peptide-1 secretion (peak concentrations and area under the curve) clearly decreased after reversal, while concentrations of glucose-dependent insulinotropic polypeptide and ghrelin increased. Insulin clearance declined after reversal, whereas clamp-estimated peripheral insulin sensitivity was unchanged. The person remained without symptoms of hypoglycaemia, but had experienced significant weight gain at 15-month follow-up.

DISCUSSION

Accelerated nutrient absorption may be a driving force behind postprandial hyperinsulinaemic hypoglycaemia after Roux-en-Y gastric bypass. Re-routing of nutrients by reversal of the Roux-en-Y gastric bypass diminished postprandial plasma glucose excursions, alleviated postprandial insulin and glucagon-like peptide-1 hypersecretion and eliminated postprandial hypoglycaemia, which emphasizes the importance of altered gut-islet cell crosstalk for glucose metabolism after Roux-en-Y gastric bypass.

Visualization of air and metal inhomogeneities in phantoms irradiated by carbon ion beams using prompt secondary ions

PURPOSE

Non-invasive methods for monitoring of the therapeutic ion beam extension in the patient are desired in order to handle deteriorations of the dose distribution related to changes of the patient geometry. In carbon ion radiotherapy, secondary light ions represent one of potential sources of information about the dose distribution in the irradiated target. The capability to detect range-changing inhomogeneities inside of an otherwise homogeneous phantom, based on single track measurements, is addressed in this paper.

METHODS

Air and stainless steel inhomogeneities, with PMMA equivalent thickness of 10mm and 4.8mm respectively, were inserted into a PMMA-phantom at different positions in depth. Irradiations of the phantom with therapeutic carbon ion pencil beams were performed at the Heidelberg Ion Beam Therapy Center. Tracks of single secondary ions escaping the phantom under irradiation were detected with a pixelized semiconductor detector Timepix. The statistical relevance of the found differences between the track distributions with and without inhomogeneities was evaluated.

RESULTS

Measured shifts of the distal edge and changes in the fragmentation probability make the presence of inhomogeneities inserted into the traversed medium detectable for both, 10mm air cavities and 1mm thick stainless steel. Moreover, the method was shown to be sensitive also on their position in the observed body, even when localized behind the Bragg-peak.

CONCLUSIONS

The presented results demonstrate experimentally, that the method using distributions of single secondary ion tracks is sensitive to the changes of homogeneity of the traversed material for the studied geometries of the target.

Tyrosinemia type II: Mutation update, 11 novel mutations and description of 5 independent subjects with a novel founder mutation

BACKGROUND

Tyrosinemia type II, also known as Richner-Hanhart Syndrome, is an extremely rare autosomal recessive disorder, caused by mutations in the gene encoding hepatic cytosolic tyrosine aminotransferase, leading to the accumulation of tyrosine and its metabolites which cause ocular and skin lesions, that may be accompanied by neurological manifestations, mostly intellectual disability.

AIMS

To update disease-causing mutations and current clinical knowledge of the disease.

MATERIALS AND METHODS

Genetic and clinical information were obtained from a collection of both unreported and previously reported cases.

RESULTS

We report 106 families, represented by 143 individuals, carrying a total of 36 genetic variants, 11 of them not previously known to be associated with the disease. Variants include 3 large deletions, 21 non-synonymous and 5 nonsense amino-acid changes, 5 frameshifts and 2 splice variants. We also report 5 patients from Gran Canaria, representing the largest known group of unrelated families sharing the same P406L mutation.

CONCLUSIONS

Data analysis did not reveal a genotype-phenotype correlation, but stressed the need of early diagnosis: All patients improved the oculocutaneous lesions after dietary treatment but neurological symptoms prevailed. The discovery of founder mutations in isolated populations, and the benefits of early intervention, should increase diagnostic awareness in newborns.

Abstract P5-15-13: Capecitabine in combination with bendamustine in pretreated women with HER2-negative metastatic breast cancer: Final PFS results of a phase II trial (AGMT MBC-6)

Background: Capecitabine is a well-established treatment option in HER2-negative advanced breast cancer (ABC) patients. Bendamustine is a generally well tolerated cytotoxic drug. Since bendamustine has already shown anticancer activity in ABC we evaluated the efficacy and tolerability of bendamustine in combination with capecitabine in pretreated patients with ABC. Here we present the final PFS results of this phase II trial.

Patients and methods: MBC-6 is a non-randomized, multicenter, open-label, single-arm phase II study in patients with HER2-negative ABC (ClinicalTrials.gov: NCT01891227). All patients were pretreated with anthracyclines and/or taxans and had measurable disease according to RECIST 1.1. Patients received 1000 mg/m2 capecitabine twice daily on days 1 to 14 in combination with 80 mg/m2 bendamustine on day 1 and 8 of a 3-week cycle for a maximum of 6 cycles. Afterwards capecitabine was continued as monotherapy. The primary endpoint was overall response rate (ORR). Secondary endpoints were progression-free survival (PFS), clinical benefit rate (CBR), safety and quality of life.

Results: From September 2013 to May 2015, 40 patients were recruited in eight Austrian centers. Median age was 60 years (range 29-77). Twenty-five percent of patients had triple-negative disease (TNBC) and 93% showed visceral involvement. Sixty-five percent had received prior chemotherapy in the (neo)adjuvant setting and 63% for ABC (43% one line, 15% two lines, 5% three lines). All patients with ER-positive disease had received prior endocrine therapy.At data cut-off on 06/08/16 overall 39 of 40 patients had discontinued treatment with a median PFS of 7.0 months (95% CI 4.6-9.5), 7.4 months in ER-positive and 4.0 months in triple negative disease (TNBC), respectively. Twelve patients (30%) experienced at least one drug related non-hematological AE ≥ grade 3 during combination treatment and further 6 patients (15%) during capecitabine maintenance. Three grade 4 hematological AEs (neutropenia) were observed. One patient died as a result of restrictive cardiomyopathy, where a relationship to capecitabine cannot be excluded, but seems unlikely.

Conclusion: The combination of capecitabine and bendamustine shows promising efficacy and a moderate toxicity profile. Further evaluation of this drug combination is warranted.Background: Capecitabine is a well-established treatment option in HER2-negative advanced breast cancer (ABC) patients. Bendamustine is a generally well tolerated cytotoxic drug. Since bendamustine has already shown anticancer activity in ABC we evaluated the efficacy and tolerability of bendamustine in combination with capecitabine in pretreated patients with ABC. Here we present the final PFS results of this phase II trial.

Patients and methods: MBC-6 is a non-randomized, multicenter, open-label, single-arm phase II study in patients with HER2-negative ABC (ClinicalTrials.gov: NCT01891227). All patients were pretreated with anthracyclines and/or taxans and had measurable disease according to RECIST 1.1. Patients received 1000 mg/m2 capecitabine twice daily on days 1 to 14 in combination with 80 mg/m2 bendamustine on day 1 and 8 of a 3-week cycle for a maximum of 6 cycles. Afterwards capecitabine was continued as monotherapy. The primary endpoint was overall response rate (ORR). Secondary endpoints were progression-free survival (PFS), clinical benefit rate (CBR), safety and quality of life.

Results: From September 2013 to May 2015, 40 patients were recruited in eight Austrian centers. Median age was 60 years (range 29-77). Twenty-five percent of patients had triple-negative disease (TNBC) and 93% showed visceral involvement. Sixty-five percent had received prior chemotherapy in the (neo)adjuvant setting and 63% for ABC (43% one line, 15% two lines, 5% three lines). All patients with ER-positive disease had received prior endocrine therapy.At data cut-off on 06/08/16 overall 39 of 40 patients had discontinued treatment with a median PFS of 7.0 months (95% CI 4.6-9.5), 7.4 months in ER-positive and 4.0 months in triple negative disease (TNBC), respectively. Twelve patients (30%) experienced at least one drug related non-hematological AE ≥ grade 3 during combination treatment and further 6 patients (15%) during capecitabine maintenance. Three grade 4 hematological AEs (neutropenia) were observed. One patient died as a result of restrictive cardiomyopathy, where a relationship to capecitabine cannot be excluded, but seems unlikely.

Conclusion: The combination of capecitabine and bendamustine shows promising efficacy and a moderate toxicity profile. Further evaluation of this drug combination is warranted.

Citation Format: Rinnerthaler G, Gampenrieder SP, Voskova D, Petzer A, Hubalek M, Petru E, Hartmann B, Andel J, Balic M, Melchardt T, Ulmer H, Mlineritsch B, Greil R. Capecitabine in combination with bendamustine in pretreated women with HER2-negative metastatic breast cancer: Final PFS results of a phase II trial (AGMT MBC-6) [abstract]. In: Proceedings of the 2016 San Antonio Breast Cancer Symposium; 2016 Dec 6-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2017;77(4 Suppl):Abstract nr P5-15-13.

[The time-related risk for knee osteoarthritis after ACL injury. Results from a systematic review]

AIM

The aim of this review was to evaluate the time-related risk for knee osteoarthritis in patients after ACL injury.

MATERIALS AND METHODS

The primary search was carried out in different medical databases with the deadline 12.01.2014. The search strategy for the evaluation was [ACL] AND [osteoarthritis] including "all fields". All 1656 title/abstracts were reviewed by two independent researchers who selected 140 papers for full text review. Finally, a total of 21 relevant publications were identified for inclusion in this current paper.

RESULTS

The incidence of knee osteoarthritis rises significantly over time. Two years after injury it was 6.9%, after 5 years 32.2%, after 7 years 36.3%, and after 10 years 79.6%. At the same time, the crude relative risk of OA rises as the time interval since injury increases. The relative risk of OA has already doubled by 2 years after ACL injury). By 7 years it has increased fivefold and compared with OA status at the time of injury it is still increasing significantly after 10 years.

CONCLUSIONS

The ACL injury is a significant risk factor for the development of early-onset secondary knee osteoarthritis. Within 5 years of the injury the knee shows clear signs of osteoarthritis on MRI. However, these lesions are often not associated with any clinical signs. Knee osteoarthritis as a severe disease starts 8 years or later after the injury, when it requires treatment.

Peptide YY and glucagon-like peptide-1 contribute to decreased food intake after Roux-en-Y gastric bypass surgery

BACKGROUND/OBJECTIVES

Exaggerated postprandial secretion of glucagon-like peptide-1 (GLP-1) and peptide YY (PYY) may explain appetite reduction and weight loss after Roux-en-Y gastric bypass (RYGB), but causality has not been established. We hypothesized that food intake decreases after surgery through combined actions from GLP-1 and PYY. GLP-1 actions can be blocked using the GLP-1 receptor antagonist Exendin 9-39 (Ex-9), whereas PYY actions can be inhibited by the administration of a dipeptidyl peptidase-4 (DPP-4) inhibitor preventing the formation of PYY_3-36.

SUBJECTS/METHODS

Appetite-regulating gut hormones and appetite ratings during a standard mixed-meal test and effects on subsequent ad libitum food intake were evaluated in two studies: in study 1, nine patients with type 2 diabetes were examined prospectively before and 3 months after RYGB with and without Ex-9. In study 2, 12 RYGB-operated patients were examined in a randomized, placebo-controlled, crossover design on four experimental days with: (1) placebo, (2) Ex-9, (3) the DPP-4 inhibitor, sitagliptin, to reduce formation of PYY_3-36 and (4) Ex-9/sitagliptin combined.

RESULTS

In study 1, food intake decreased by 35% following RYGB compared with before surgery. Before surgery, GLP-1 receptor blockage increased food intake but no effect was seen postoperatively, whereas PYY secretion was markedly increased. In study 2, combined GLP-1 receptor blockage and DPP-4 inhibitor mediated lowering of PYY_3-36 increased food intake by ~20% in RYGB patients, whereas neither GLP-1 receptor blockage nor DPP-4 inhibition alone affected food intake, perhaps because of concomitant marked increases in the unblocked hormone.

CONCLUSIONS

Blockade of actions from only one of the two L-cell hormones, GLP-1 and PYY_3-36, resulted in concomitant increased secretion of the other, probably explaining the absent effect on food intake on these experimental days. Combined blockade of GLP-1 and PYY actions increased food intake after RYGB, supporting that these hormones have a role in decreased food intake postoperatively.

Burn Care on Cruise Ships-Epidemiology, international regulations, risk situation, disaster management and qualification of the ship's doctor

With the increasing numbers of passengers and crew on board vessels that are becoming larger and larger, the demand for ship's doctors who can adequately treat burns on board has also increased. In the cruise ship industry it is usually those doctor's with internal and general medical training who are recruited from an epidemiological point of view. Training content or recommendations for the treatment of thermal lesions with the limited options available in ship's hospitals and where doctors with no surgical training operate do not yet exist. The guidelines recommended by the Cruise Lines International Association (CLIA) regarding medical staff have only included physicians with minor surgical skills until now. With the introduction of the ATLS(®) course developed by the American College of Surgeons, the requirements for the qualification of the ship's doctor on board cruise ships shall change from January 2017. The article discusses the question of whether having completed the ATLS(®) course, the ship's doctor is trained to adequately treat thermal lesions or severe burns persons on-board, and presents the current discussion on the training content for ship's doctors within the International Maritime Health Association (IMHA). It also provides an overview of existing international regulatory frameworks, the risks presented by a fire on board, the problem of treating burns victims out of reach of coastal rescue services, and alternative training concepts for ship's doctors regarding the therapy of thermal lesions on-board.

N-terminally and C-terminally truncated forms of glucose-dependent insulinotropic polypeptide are high-affinity competitive antagonists of the human GIP receptor

Background and Purpose

Glucose‐dependent insulinotropic polypeptide (GIP) affects lipid, bone and glucose homeostasis. High‐affinity ligands for the GIP receptor are needed to elucidate the physiological functions and pharmacological potential of GIP in vivo. GIP(1–30)NH₂ is a naturally occurring truncation of GIP(1–42). Here, we have characterized eight N‐terminal truncations of human GIP(1–30)NH₂.

Experimental Approach

COS‐7 cells were transiently transfected with human GIP receptors and assessed for cAMP accumulation upon ligand stimulation or competition binding with ¹²⁵I‐labelled GIP(1–42), GIP(1–30)NH₂, GIP(2–30)NH₂ or GIP(3–30)NH₂.

Key Results

GIP(1–30)NH₂ displaced ¹²⁵I‐GIP(1–42) as effectively as GIP(1–42) (K_i 0.75 nM), whereas the eight truncations displayed lower affinities (K_i 2.3–347 nM) with highest affinities for GIP(3–30)NH₂ and GIP(5–30)NH₂ (5–30)NH₂. Only GIP(1–30)NH₂ (E_max 100% of GIP(1–42)) and GIP(2–30)NH₂ (E_max 20%) were agonists. GIP(2‐ to 9–30)NH₂ displayed antagonism (IC₅₀ 12–450 nM) and Schild plot analyses identified GIP(3–30)NH₂ and GIP(5–30)NH₂ as competitive antagonists (K_i 15 nM). GIP(3–30) NH₂ was a 26‐fold more potent antagonist than GIP(3–42). Binding studies with agonist (¹²⁵I‐GIP(1–30)NH₂), partial agonist (¹²⁵I‐GIP(2–30)NH₂) and competitive antagonist (¹²⁵I‐GIP(3–30)NH₂) revealed distinct receptor conformations for these three ligand classes.

Conclusions and Implications

The N‐terminus is crucial for GIP agonist activity. Removal of the C‐terminus of the endogenous GIP(3–42) creates another naturally occurring, more potent, antagonist GIP(3–30)NH₂, which like GIP(5–30)NH₂, was a high‐affinity competitive antagonist. These peptides may be suitable tools for basic GIP research and future pharmacological interventions.

Impact of body weight on antidiabetic treatment and predictors of weight control under real-world conditions: a 2-year follow-up of DiaRegis cohort

AIMS

Treatment strategies for obese patients with type 2 diabetes mellitus aim to increase physical activity, reduce body weight, and improve glucose control using weight-beneficial antidiabetic drugs. The objective of this study was to determine whether these strategies are implemented, and to identify factors predictive of glucose control and body weight management in a large, real-world patient population.

METHODS

The prospective DiaRegis cohort study included 3807 patients with type 2 diabetes in whom the treating physician decided to intensify and optimize treatment because of insufficient glucose control.

RESULTS

Antidiabetic treatment of overweight and obese patients was compared with that of normal-weight patients over a 2-years follow-up period, and multivariate analyses were performed to identify predictors of body weight loss. Among the 3807 participants, 92.5 % were overweight or obese. Normal-weight participants were more often treated with sulfonylureas or insulin, and overweight and obese patients with metformin or glucagon-like peptide (GLP)-1 analogues. Predictors of weight loss were body mass index (BMI) ≥30 kg/m(2) and any reported physical activity.

CONCLUSIONS

DiaRegis study shows that under real-world conditions, antidiabetic drug therapy is performed dependent on body weight. This strategy results in adequate glucose control and moderate weight reductions in overweight and obese patients. Weight loss is affected by treatment with weight-beneficial drugs, but also by any reported physical activity. However, only a small subgroup of patients perform physical activity. Initiation and maintenance of a physically active lifestyle remains a significant challenge for physicians, and patients with type 2 diabetes.

Species-specific action of (Pro3)GIP - a full agonist at human GIP receptors, but a partial agonist and competitive antagonist at rat and mouse GIP receptors

Background and Purpose

Specific, high potency receptor antagonists are valuable tools when evaluating animal and human physiology. Within the glucose‐dependent, insulinotropic polypeptide (GIP) system, considerable attention has been given to the presumed GIP receptor antagonist, (Pro3)GIP, and its effect in murine studies. We conducted a pharmacological analysis of this ligand including interspecies differences between the rodent and human GIP system.

Experimental Approach

Transiently transfected COS‐7 cells were assessed for cAMP accumulation upon ligand stimulation and assayed in competition binding using ¹²⁵I‐human GIP. Using isolated perfused pancreata both from wild type and GIP receptor‐deficient rodents, insulin‐releasing, glucagon‐releasing and somatostatin‐releasing properties in response to species‐specific GIP and (Pro3)GIP analogues were evaluated.

Key Results

Human (Pro3)GIP is a full agonist at human GIP receptors with similar efficacy (E_max) for cAMP production as human GIP, while both rat and mouse(Pro3)GIP were partial agonists on their corresponding receptors. Rodent GIPs are more potent and efficacious at their receptors than human GIP. In perfused pancreata in the presence of 7 mM glucose, both rodent (Pro3)GIP analogues induced modest insulin, glucagon and somatostatin secretion, corresponding to the partial agonist activities observed in cAMP production.

Conclusions and Implications

When evaluating new compounds, it is important to consider interspecies differences both at the receptor and ligand level. Thus, in rodent models, human GIP is a comparatively weak partial agonist. Human (Pro3)GIP was not an antagonist at human GIP receptors, so there is still a need for a potent antagonist in order to elucidate the physiology of human GIP.

[Assessment of REC (Reduction in Earning Capacity) after Thermal Trauma as Part of the Appraisal Process for Statutory Accident Insurance in Germany (Part 2): The New REC Form Developed by Ottomann and Hartmann in 2010]

The calculation of REC forms the basis of expert opinions for the purposes of making accident insurance assessments after an occupational accident or an accident suffered en route while travelling to or from the workplace. The estimation of REC is based on a procedure quoted in the 1995 "Jahrbuch der Versicherungsmedizin" (Yearbook of Insurance Medicine) using a form developed by Henkel von Donnersmarck and Hoerbrand. The overall estimation of damages resulting from the accident comprises 3 main components, namely the functional impairment, the assessment of local findings and the resulting somatic and vegetative complaints. The criteria for all 3 components are nevertheless imprecise and open to a great deal of interpretation on the part of the evaluator, leading to a highly variable and subjective overall assessment of REC. The new REC form includes a modified factor-based categorisation of the scar quality and the localisation, so that assessment can now be carried out in a differentiated manner. Visible, stigmatising areas such as the neck are provided with their own Q values. The pigmental and textural alterations describing the scar quality are now more precisely defined. Considering the complexity of the somatic and vegetative alterations, more precise (objective) assessments can now be derived. The new REC form increases the validity and transparency of post-thermal trauma REC assessments for the purposes of making statutory accident insurance assessments.