Increase in the incidence of severe hypoglycaemia in people with Type 2 diabetes in spite of new drugs: analysis based on health insurance data from Germany

AIM

To evaluate the use of new anti-hyperglycaemic agents that offer effective glycaemic control while reducing risk of hypoglycaemia, by analysing the incidence rates of severe hypoglycaemia in 2006 vs 2011 in relation to the medication.

METHODS

This cross-sectional, population-based study used German health insurance data. All adults diagnosed with Type 2 diabetes mellitus (extrapolated to the German population: 6.35 million in 2006 and 7.52 million in 2011) were screened for severe hypoglycaemia. Anti-hyperglycaemic agents were identified by their Anatomical Therapeutic Chemical code, and defined daily doses of each medication were calculated.

RESULTS

The severe hypoglycaemic event rate was 460 per 100,000 people/year in 2006 and 490 per 100,000 people/year in 2011. In 2006 and 2011, 10.9% and 7.3%, respectively, of all people with severe hypoglycaemia were on sulfonylureas, while 12.7% and 9.3%, respectively, were on a combination therapy of metformin and sulfonylureas. Among those with severe hypoglycaemia, there were no prescriptions of dipeptidyl peptidase-4 inhibitors or glucagon-like peptide-1 receptor agonists in 2006, but in 2011, 1.55% and 0.17%, of those with severe hypoglycaemia were receiving the respective treatments. In 2006 vs 2011, human insulin was prescribed for 11.3% vs 10.3% of people with severe hypoglycaemia, while insulin analogues were prescribed for 5.4% vs 8.1%, and mixed human insulins for 19.7% vs 14.0% of patients with severe hypoglycaemia. People receiving insulin analogue therapy had a higher risk of severe hypoglycaemia than those receiving metformin, after adjusting for age, gender, nephropathy diagnosis and year of survey (odds ratio 14.6; CI 13.3-15.9).

CONCLUSION

The incidence of severe hypoglycaemic events in Germany increased between 2006 and 2011, despite increased use of newer anti-hyperglycaemic agents and decreased use of insulins.

Hematopoiesis is prognostic for toxicity and survival of 223Radium treatment in patients with metastatic castration-resistant prostate cancer

OBJECTIVE

We evaluated the impact of pre-therapeutic hematopoiesis on survival, hematotoxicity (HT) and number of ²²³Radium (²²³Ra) treatments in patients with metastatic castration-resistant prostate cancer.

SUBJECTS AND METHOD

Hemoglobin-levels (Hb), the number of platelets (Plts), leukocytes (Leuk), and survival data were collected in 56 patients treated with ²²³Ra. Pre-therapeutic hematopoiesis as well as adverse events during and after therapy were scored (grade 0-4) according to the CTCAE recommendations. The association of pre-therapeutic hematopoiesis, survival, HT and numbers of ²²³Ra cycles was analyzed.

RESULTS

Median survival in all patients was 69.9 weeks; 77% of patients had pre-existing impaired Hb (1.7% grade 3, 12.5% grade 2, 62.5% grade 1). 8/56 (14.3%) had impaired Plt (grade 1) Maximum toxicity (Tox) grades of patients during treatment were grade 4 (Hb 1.7%; Plt 1.7%), grade 3 (Hb 14.3%; Plt 7.1%; Leu 7.1%), grade 2 (Hb 33.9%; Plt 7.1%; Leu 23.2%), grade 1 (Hb 46.4%; Plt 17.9%; Leu 23.2%) and grade 0 (Hb 5.4%; Plt 66.1%; Leu 44.6%). Interestingly, patients with thrombocytopenia had a significantly shorter survival compared to those with normal Plt levels (21 weeks vs not reached; P<0.003). As expected patients with pre-therapeutic low Hb-level (<10g/dL) had a significantly shorter survival compared to those with Hb-level >10g/dL (28 weeks vs not reached, P<0.004), whereas survival of patients with mildly impaired Hb (>10 but <13.5g/dL) did not differ from patients with normal levels of Hb (X vs. Y, P=...). Also patients with impaired Hb also developed significantly more grade 3 and 4 HT (Hb <10g/dL: 42.9 vs 14.3%, P<0.001; Plt <150G/mL: 25.0% vs 6.3%; P=0.002) and received significantly fewer treatment cycles (Hb<10g/dL: 5.1 vs 5.8, P<0.04; Plt <150G/mL: 3.4 vs 5.6; P<0.001). Neither extent of bone metastases nor previous chemotherapy were associated with survival, number of ²²³Ra cycles and HT.

CONCLUSION

Patients with metastatic castration-resistant prostate cancer and impaired hematopoiesis, in particular thrombocytopenia and anemia, before ²²³Ra therapy suffer from significantly more high-grade HT, shorter survival and receive significantly fewer ²²³Ra treatments. Therefore, Hb-levels and platelet counts are essential parameters for adequate patient selection for ²²³Ra therapy.

Diabetes-related burden and distress in people with diabetes mellitus at primary care level in Germany

AIMS

The importance of diabetes-related distress for the treatment of diabetes is emphasised in national and international guidelines recommending routinely screening for psychosocial problems. Data of investigations regarding diabetes-related distress on primary care are rare in Germany though most people with diabetes are treated without insulin therapy at primary care level.

METHODS

Three hundred and forty-five people with diabetes mellitus type 2 (DM2, n = 336, 229 without and 107 with insulin therapy) and type 1 (DM1, n = 9) were interviewed with the PAID questionnaire in the period from 1 October 2015 to 31 December 2015 in a general practice. A PAID score ≥40 (range 0-100) was considered as high diabetes-related distress.

RESULTS

The mean PAID score of all participants was 3.9 ± 7.0 (DM2 without insulin 2.7 ± 6.3, DM2 with insulin therapy 6.0 ± 8.0, DM1 6.8 ± 4.9) and far below the threshold of 40 points. Only 1.2% of all responders showed high diabetes-related distress (score ≥40). People on insulin therapy with HbA1c >7.5% and with diagnosed depression prior to the study scored significantly higher. Furthermore, there are weak correlations between the PAID score and HbA1c (r = 0.253, p < 0.001), duration of diabetes (r = 0.169, p = 0.002), insulin dosage (r = 0.283, p < 0.001) and age (r = -0.129, p = 0.016).

CONCLUSIONS

Only 1.2% of our outpatients with diabetes on primary care level showed high diabetes-related distress. Higher rates in the current literature are probably due to not investigating on primary care level. Guidelines should consider this.

Metabolic control and hypoglycaemia in people with type 2 diabetes on conventional or intensified insulin therapy: a 22 year retrospective single centre survey

BACKGROUND

Multiple insulin injection therapy can easily be adapted to the patient's needs. Therefore, it is supposed that more intensive insulin therapy is associated with better metabolic control and less hypoglycaemia compared with a conventional insulin strategy in patients with type 2 diabetes.

METHODS

HbA1c and incidence of non-severe and severe hypoglycaemia were analysed with regard to the strategy of insulin therapy [multiple insulin injection therapy with preprandial insulin with or without basal insulin or conventional insulin therapy with twice-daily premix insulin] from 20 943 visits of 1417 people treated with insulin with type 2 diabetes in a university outpatient department for endocrinology and metabolic diseases over a period of 22 years.

RESULTS

Multiple insulin injection therapy was used in 13 896 (66.4%) of all 20 942 visits. Compared with conventional insulin therapy, these patients were younger (62.0 vs 68.7 years; p < 0.001), had a slightly longer diabetes duration (16.5 vs 15.8 years; p < 0.001) and higher body mass index (32.8 vs 30.9 kg/m(2) ; p < 0.001), a higher insulin dose (76.4 vs 46.5 IU/day; p < 0.001), more frequent blood glucose monitorings/week (24.2 vs 14.8; p < 0.001), a slightly lower HbA1c [7.7 (61.2) vs 7.9% (62.9 mmol/mol); p < 0.001] but more non-severe hypoglycaemic incidences per week (0.3 vs 0.2; p = 0.01). Episodes of severe hypoglycaemia were rare and comparable (0.01/patient/year) with both insulin therapy strategies.

CONCLUSIONS

Multiple insulin injection therapy and conventional insulin therapy yielded comparable metabolic control with HbA1c below 8% (63.9 mmol/mol), but multiple insulin injection therapy is associated with higher body mass index and higher incidence of non-severe hypoglycaemia. Copyright © 2016 John Wiley & Sons, Ltd.

A MONTE CARLO STUDY OF SIMULATED MEASUREMENTS OF RADIONUCLIDES IN BONE

When measuring the internally deposited activity in the bone of a subject, the placement of the detector is critical. This study reports the simulated counting efficiencies for three counting geometries, the skull, knee and shin, using 13 different voxel phantoms. It shows that the range of counting efficiencies for a given geometry is large for the studied phantoms, especially at low energies. Skull counting offers higher efficiency for low energies such as the 17 keV compared to knee counting or shin counting, but this advantage disappears when the energy is higher such as at 185 keV. This work also shows that the calibration phantom may greatly impact the accuracy of the activity estimate in bone counting, with uncertainties increasing greatly as the photon energy is reduced. Estimating the activity of a radionuclide in bone from direct counting has large uncertainties, and the dose calculated from a skeleton measurement would need careful analysis and, if possible, supporting data from other bioassay measurements.

Principles of self-adjustment of insulin dose in people with diabetes type 2 and flexible insulin therapy

AIMS

Structured treatment and education programmes for people with type 2 diabetes mellitus (T2DM) and flexible insulin therapy provide rules for self-adjustment of insulin dose, that are extensively trained. The aim of this cohort study was to register current principles and the frequency of self-adjustment of insulin dose and their association with metabolic control in people with T2DM.

METHODS

Details of insulin dose adjustment were assessed by a structured interview in 149 people with T2DM on flexible insulin therapy (mean HbA1c 7.1%/53.8mmol/mol, age 65y, diabetes duration 19.0y, BMI 33.8kg/m(2)) in a tertiary care centre. The frequency of insulin dose adjustments was obtained from the last 28days of the patients' diaries.

RESULTS

Insulin dose adjustment by adjustment rules was used by 33 people (22.1%) and by personal experience/feeling in 111 participants (74.5%). People adjusting by rules were younger (60.9±9.8 vs. 65.7±9.2, p=0.011) and did more insulin dose adjustments per 28days (50.0±31.0 vs. 33.4±23.5, p=0.016). HbA1c and incidence of hypoglycaemia were comparable. There were no differences in satisfaction of treatment, quality of life as well as current well-being between the groups.

CONCLUSIONS

Only a fifth of the participants used the rule trained within the education programme to adjust their insulin dose. The majority adjusted their insulin dose by personal experience/feeling. However, people in both groups were able to adjust their insulin dose. Although people using adjustment rules adjust their insulin dose more frequently, HbA1c and the incidence of hypoglycaemia was similar compared to those using personal experience/feeling.

32nd International Austrian Winter Symposium : Zell am See, the Netherlands. 20-23 January 2016

A1 68Ga-PSMA PET/CT in staging and restaging of Prostate Cancer Patients: comparative study with 18F-Choline PET/CT

W Langsteger, A Rezaee, W Loidl, HS Geinitz, F Fitz, M Steinmair, G Broinger, L Pallwien-Prettner, M Beheshti

A2 F18 Choline PET – CT: an accurate diagnostic tool for the detection of parathyroid adenoma?

L Imamovic, M Beheshti, G Rendl, D Hackl, O Tsybrovsky, M Steinmair, K Emmanuel, F Moinfar, C Pirich, W Langsteger

A3 [18F]Fluoro-DOPA-PET/CT in the primary diagnosis of medullary thyroid carcinoma

A Bytyqi, G Karanikas, M Mayerhöfer, O Koperek, B Niederle, M Hartenbach

A4 Variations of clinical PET/MR operations: An international survey on the clinical utilization of PET/MRI

T Beyer, K Herrmann, J Czernin

A5 Standard Dixon-based attenuation correction in combined PET/MRI: Reproducibility and the possibility of Lean body mass estimation

I Rausch, P Rust, MD DiFranco, M Lassen, A Stadlbauer, ME Mayerhöfer, M Hartenbach, M Hacker, T Beyer

A6 High resolution digital FDG PET/MRI imaging for assessment of ACL graft viability

K Binzel, R Magnussen, W Wei, MU Knopp, DC Flanigan, C Kaeding, MV Knopp

A7 Using pre-existing hematotoxicity as predictor for severe side effects and number of treatment cycles of Xofigo therapy

A Leisser, M Nejabat, M Hartenbach, G Kramer, M Krainer, M Hacker, A Haug

A8 QDOSE – comprehensive software solution for internal dose assessment

Wencke Lehnert, Karl Schmidt, Sharok Kimiaei, Marcus Bronzel, Andreas Kluge

A9 Clinical impact of Time-of-Flight on next-generation digital PET imaging of Yttrium-90 radioactivity following liver radioembolization

CL Wright, K Binzel, J Zhang, Evan Wuthrick, Piotr Maniawski, MV Knopp

A10 Snakes in patients! Lessons learned from programming active contours for automated organ segmentation

M Blaickner, E Rados, A Huber, M Dulovits, H Kulkarni, S Wiessalla, C Schuchardt, RP Baum, B Knäusl, D Georg

A11 Influence of a genetic polymorphism on brain uptake of the dual ABCB1/ABCG2 substrate [11C]tariquidar

M Bauer, B Wulkersdorfer, W Wadsak, C Philippe, H Haslacher, M Zeitlinger, O Langer

A12 Outcome prediction of temporal lobe epilepsy surgery from P-glycoprotein activity. Pooled analysis of (R)-[11C]-verapamil PET data from two European centres

M Bauer, M Feldmann, R Karch, W Wadsak, M Zeitlinger, MJ Koepp, M-C Asselin, E Pataraia, O Langer

A13 In-vitro and in-vivo characterization of [18F]FE@SNAP and derivatives for the visualization of the melanin concentrating hormone receptor 1

M Zeilinger, C Philippe, M Dumanic, F Pichler, J Pilz, M Hacker, W Wadsak, M Mitterhauser

A14 Reducing time in quality control leads to higher specific radioactivity of short-lived radiotracers

L Nics, B Steiner, M Hacker, M Mitterhauser, W Wadsak

A15 In vitro 11C-erlotinib binding experiments in cancer cell lines with epidermal growth factor receptor mutations

A Traxl, Thomas Wanek, Kushtrim Kryeziu, Severin Mairinger, Johann Stanek, Walter Berger, Claudia Kuntner, Oliver Langer

A16 7-[11C]methyl-6-bromopurine, a PET tracer to measure brain Mrp1 function: radiosynthesis and first PET evaluation in mice

S Mairinger, T Wanek, A Traxl, M Krohn, J Stanek, T Filip, M Sauberer, C Kuntner, J Pahnke, O Langer

A17 18F labeled azidoglucose derivatives as “click” agents for pretargeted PET imaging

D Svatunek, C Denk, M Wilkovitsch, T Wanek, T Filip, C Kuntner-Hannes, J Fröhlich, H Mikula

A18 Bioorthogonal tools for PET imaging: development of radiolabeled 1,2,4,5-Tetrazines

C Denk, D Svatunek, T Wanek, S Mairinger, J Stanek, T Filip, J Fröhlich, H Mikula, C Kuntner-Hannes

A19 Preclinical evaluation of [18F]FE@SUPPY- a new PET-tracer for oncology

T Balber, J Singer, J Fazekas, C Rami-Mark, N Berroterán-Infante, E Jensen-Jarolim, W Wadsak, M Hacker, H Viernstein, M Mitterhauser

A20 Investigation of Small [18F]-Fluoroalkylazides for Rapid Radiolabeling and In Vivo Click Chemistry

C Denk, D Svatunek, B Sohr, H Mikula, J Fröhlich, T Wanek, C Kuntner-Hannes, T Filip

A21 Microfluidic 68Ga-radiolabeling of PSMA-HBED-CC using a flow-through reactor

S Pfaff, C Philippe, M Mitterhauser, M Hartenbach, M Hacker, W Wadsak

A22 Influence of 24-nor-ursodeoxycholic acid on hepatic disposition of [18F]ciprofloxacin measured with positron emission tomography

T Wanek, E Halilbasic, M Visentin, S Mairinger, B Stieger, C Kuntner, M Trauner, O Langer

A23 Automated 18F-flumazenil production using chemically resistant disposable cassettes

P Lam, M Aistleitner, R Eichinger, C Artner

A24 Similarities and differences in the synthesis and quality control of 177Lu-DOTA-TATE, 177Lu -HA-DOTA-TATE and 177Lu-DOTA-PSMA (PSMA-617)

H Eidherr, C Vraka, A Haug, M Mitterhauser, L Nics, M Hartenbach, M Hacker, W Wadsak

A25 68Ga- and 177Lu-labelling of PSMA-617

H Kvaternik, R Müller, D Hausberger, C Zink, RM Aigner

A26 Radiolabelling of liposomes with 67Ga and biodistribution studies after administration by an aerosol inhalation system

U Cossío, M Asensio, A Montes, S Akhtar, Y te Welscher, R van Nostrum, V Gómez-Vallejo, J Llop

A27 Fully automated quantification of DaTscan SPECT: Integration of age and gender differences

F VandeVyver, T Barclay, N Lippens, M Troch

A28 Lesion-to-background ratio in co-registered 18F-FET PET/MR imaging – is it a valuable tool to differentiate between low grade and high grade brain tumor?

L Hehenwarter, B Egger, J Holzmannhofer, M Rodrigues-Radischat, C Pirich

A29 [11C]-methionine PET in gliomas - a retrospective data analysis of 166 patients

N Pötsch, I Rausch, D Wilhelm, M Weber, J Furtner, G Karanikas, A Wöhrer, M Mitterhauser, M Hacker, T Traub-Weidinger

A30 18F-Fluorocholine versus 18F-Fluorodeoxyglucose for PET/CT imaging in patients with relapsed or progressive multiple myeloma: a pilot study

T Cassou-Mounat, S Balogova, V Nataf, M Calzada, V Huchet, K Kerrou, J-Y Devaux, M Mohty, L Garderet, J-N Talbot

A31 Prognostic benefit of additional SPECT/CT in sentinel lymph node mapping of breast cancer patients

S Stanzel, G Pregartner, T Schwarz, V Bjelic-Radisic, B Liegl-Atzwanger, R Aigner

A32 Evaluation of diagnostic value of TOF-18F-FDG PET/CT in patients with suspected pancreatic cancer

S Stanzel, F Quehenberger, RM Aigner

A33 New quantification method for diagnosis of primary hyperpatahyroidism lesions and differential diagnosis vs thyropid nodular disease in dynamic scintigraphy

A Koljević Marković, Milica Janković, V Miler Jerković, M Paskaš, G Pupić, R Džodić, D Popović

A34 A rare case of diffuse pancreatic involvement in patient with merkel cell carcinoma detected by 18F-FDG

MC Fornito, D Familiari

A35 TSH-stimulated 18F-FDG PET/CT in the diagnosis of recurrent/metastatic radioiodine-negative differentiated thyroid carcinomas in patients with various thyroglobuline levels

P Koranda, H Polzerová, I Metelková, L Henzlová, R Formánek, E Buriánková, M Kamínek

A36 Breast Dose from lactation following I131 treatment

WH Thomson, C Lewis

A37 A new concept for performing SeHCAT studies with the gamma camera

WH Thomson, J O’Brien, G James, A Notghi

A38 Whole body F-18-FDG-PET and tuberculosis: sensitivity compared to x-ray-CT

H Huber, I Stelzmüller, R Wunn, M Mandl, F Fellner, B Lamprecht, M Gabriel

A39 Emerging role 18F-FDG PET-CT in the diagnosis and follow-up of the infection in heartware ventricular assist system (HVAD)

MC Fornito, G Leonardi

A40 Validation of Poisson resampling software

WH Thomson, J O’Brien, G James

A41 Protection of PET nuclear medicine personnel: problems in satisfying dose limit requirements

J Hudzietzová, J Sabol, M Fülöp

Use and Effectiveness of Continuous Subcutaneous Insulin Infusion (CSII) and Multiple Daily Insulin Injection Therapy (MIT) in Children, Adolescents and Young Adults with Type 1 Diabetes Mellitus

Today continuous subcutaneous insulin infusion (CSII) is frequently used in children and adolescents with type 1 diabetes mellitus. The present cross-sectional trial aimed to document current practice, quality of diabetes control and incidence of acute complications in different age-groups under CSII vs. multiple daily insulin injection therapy (MIT). Moreover the survey analyzed socio-demographic backgrounds of the patients.

PATIENTS AND METHODS

A total of 901 patients (age 11.5±4.0, diabetes duration 4.0±3.6 years) was entered in the database. Clinical data, laboratory parameters and, using a standardized questionnaire, socio-demographic data were assessed. For age-related analyses patients were allocated to 4 groups: pre-school children (< 6 years), pre-adolescents (≥ 6 and<11 years), adolescents (≥ 11 and<16 years) and young adults (≥ 16 and<22 years).

RESULTS

Of the cohort n=194 had a CSII, n=707 had a MIT. Patients with CSII vs. MIT had a longer diabetes duration, they used more frequently insulin analogues, performed more frequently blood-glucose self-tests and had a lower insulin dosage per kilogram body weight. In respect of HbA1c, the mean amplitude of blood-glucose excursions, but also of lipids, creatinine, microalbuminuria and blood pressure, there were no differences in neither age-group between patients with CSII and MIT. In patients with CSII and MIT, there was a tendency (p<0.05) towards an increase in HbA1c in adolescents and young adults and there was a decrease (p<0.05 for tendency) in the frequency of hypoglycaemia from the age group of young adults to pre-school children. Adolescents and young adults with CSII had a higher educational level. Pre-adolescents, adolescents and young adults with CSII have also better diabetes-related knowledge. Moreover, in all age-groups, the parents of patients with CSII had mostly a lower unemployment rate and higher educational levels.

CONCLUSIONS

The present analyses demonstrate that in all age-groups CSII provides convenient and flexible insulin delivery during routine treatment of type 1 diabetes. There is reasonable quality of diabetes control accompanied by a low incidence of hypoglycaemia and ketoacidosis. However, under CSII and MIT there is an increase of HbA1c towards adolescence. It must also highlighted that CSII seems to be expansive and that CSII is more frequently used in patients with better educational levels and deriving from higher social classes.

A literature review of the association between diffusion-weighted MRI derived apparent diffusion coefficient and tumour aggressiveness in pelvic cancer

Diffusion-weighted magnetic resonance imaging (DW-MRI) is used extensively to improve tumour detection and localization because it offers excellent soft tissue contrast between malignant and non-malignant tissues. It also provides a quantitative biomarker; the apparent diffusion coefficient (ADC) can be derived from DW-MRI sequences using multiple diffusion weightings. ADC reflects the tumour microenvironment, e.g. cell membrane integrity and cellularity and has potential for reporting on tumour aggressiveness. This review focuses on the use of the DW-MRI derived imaging biomarker ADC to reflect tumour aggressiveness and its potential impact in managing pelvic cancer patients. The clinical studies which evaluate the role of ADC in pelvic tumours (prostate, bladder, rectal, ovary, cervix and uterus) are summarized and the evidence linking ADC values with tumour aggressiveness is evaluated.

Quantitative proteomics of rat and human pancreatic beta cells

Data set description: This data set is composed by label-free alternate-scanning LC-MS/MS proteomics analysis human and Wistar rat pancreatic islet endocrine cells. The mass spectrometry data of the human and rat pancreatic beta cells and the resulting proteome search output from ProteinLynx GlobalSERVER (PLGS) have been deposited to the ProteomeXchange Consortium [1] via the PRIDE partner repository with the dataset identifiers PXD001539 (human) and PXD001816 (rat). From these mass spectrometry data, 'relative molar amount units' between cell types and across species were calculated. Biological relevance: These data provide a quantitative view on the unfractionated proteomes of human and rat beta and alpha cells. It is likely biased towards the proteins with higher molar abundance, relating to core functional pathways, but also includes several proteins with an islet-enriched expression. The quality of the cell preps is state-of-the-art, and the label-free quantitation is both precise and accurate, allowing detailed quantitative analysis.

Potential of UCHL1 as biomarker for destruction of pancreatic beta cells

There is a clinical need for plasma tests for real-time detection of beta cell destruction, as surrogate endpoint in islet transplantation and immunoprevention trials in type 1 diabetes. This study reports on the use of label-free LC-MS/MS proteomics for bottom-up selection of candidate biomarkers. Ubiquitin COOH-terminal hydrolase 1 (UCHL1) was identified as abundant protein in rat and human beta cells, showing promising beta cell-selectivity, and was selected for further validation in standardized toxicity models. In vitro, H2O2-induced necrosis of INS-1 cells and human islets resulted in intracellular UCHL1 depletion and its extracellular discharge. In vivo, streptozotocin progressively depleted UCHL1 from islet cores and in 50% of animals, an associated plasma UCHL1 surge was detected preceding the GAD65 peak. UCHL1 was cleared with a half-life of 20min. Whole-body dynamic planar imaging of (99m)-Technetium-labeled UCHL1 indicated a rapid UCHL1 uptake in the liver and spleen, followed by urinary excretion of mainly proteolytic UCHL1 fragments. We conclude that LC-MS/MS proteomics is a useful tool to prioritize biomarkers for beta cell injury with promising molar abundance. Despite its consistent UCHL1 discharge by damaged beta cells in vitro, its in vivo use might be restrained by its rapid elimination from plasma.

BIOLOGICAL SIGNIFICANCE

Our bottom-up LC-MS/MS proteomics represents a pragmatic approach to identify protein-type biomarkers of pancreatic beta cell injury. UCHL1 successfully passed sequential validation steps of beta cell-selectivity, antigenicity and toxic discharge in vitro. Whole-body dynamic planar imaging of radiolabeled recombinant UCHL1 indicated rapid clearance through the liver, spleen and urinary excretion of proteolytic fragments, likely explaining non-consistent detection in vivo. Integration of kinetic biomarker clearance studies in the a priori selection criteria is recommended before engaging in resource-intensive custom development of sensitive immunoassays for clinical translation.

Process to generate a synthetic diagnostic for microwave imaging reflectometry with the full-wave code FWR2D

A synthetic microwave imaging reflectometer (MIR) diagnostic employing the full-wave reflectometer code (FWR2D) has been developed and is currently being used to guide the design of real systems, such as the one recently installed on DIII-D. The FWR2D code utilizes real plasma profiles as input, and it is combined with optical simulation tools for synthetic diagnostic signal generation. A detailed discussion of FWR2D and the process to generate the synthetic signal are presented in this paper. The synthetic signal is also compared to a prescribed density fluctuation spectrum to quantify the imaging quality. An example is presented with H-mode-like plasma profiles derived from a DIII-D discharge, where the MIR focal is located in the pedestal region. It is shown that MIR is suitable for diagnosing fluctuations with poloidal wavenumber up to 2.0 cm(-1) and fluctuation amplitudes less than 5%.

A role for arginine-12 in thrombin-thrombomodulin-mediated activation of thrombin-activatable fibrinolysis inhibitor

BACKGROUND

Thrombin-activatable fibrinolysis inhibitor (TAFI) is a proenzyme that links coagulation and fibrinolysis. TAFI can be activated by thrombin, the thrombin-thrombomodulin complex and plasmin through cleavage of the first 92 amino acids from the enzyme. In silico analysis of the TAFI sequence revealed a potential thrombin cleavage site at Arg12. The aim of this study was to determine whether TAFI can be cleaved at Arg12 and whether this cleavage plays a role in TAFI activation.

METHODS

A peptide based on the first 18 amino acids of TAFI was used to determine whether thrombin was able to cleave at Arg12. Mass spectrometry was performed to determine whether the Arg12-cleaved peptide was released from full-length TAFI. Furthermore, a TAFI mutant in which Arg12 was replaced by a glutamine (TAFI-R12Q) was constructed and characterized with respect to its activation kinetics.

RESULTS

The peptide and mass spectrometry data showed that thrombin was able to cleave TAFI at Arg12, but with low efficiency in full-length TAFI. Characterization of TAFI-R12Q showed no difference in thrombin-mediated activation from wild-type TAFI. However, there was an approximately 60-fold impairment in activation of TAFI-R12Q by the thrombin-thrombomodulin complex.

CONCLUSIONS

Arg12 of TAFI plays an important role in thrombomodulin-mediated TAFI activation by thrombin. Thrombin is able to cleave TAFI at Arg12, but it remains to be determined whether Arg12 is part of an exosite for thrombomodulin or whether cleavage at Arg12 accelerates thrombomodulin-mediated TAFI activation.