Elevated Intact Proinsulin Levels During an Oral Glucose Challenge Indicate Progressive ?-Cell Dysfunction and May Be Predictive for Development of Type 2 Diabetes

Background:Elevated fasting intact proinsulin is a biomarker of late-stage ß-cell-dysfunction associated with clinically relevant insulin resistance. In this pilot investigation, we explored the potential value of measuring intact proinsulin as a functional predictor of ß-cell exhaustion during an oral glucose tolerance test (OGTT).Methods:The study was performed with 31 participants, 11 of whom were healthy subjects (7 female, age: 59 ± 20 years), 10 had impaired glucose tolerance (IGT, 6 female, 62 ± 10 years), and 10 had known type 2 diabetes (T2DM, 5 female, 53 ± 11 years, HbA1c: 7.0 ± 0.6%, disease duration: 8 ± 5 years). During OGTT, blood was drawn after 0 hours, 1 hour, and 2 hours for determination of glucose and intact proinsulin. Five years later, patients were again contacted to assess their diabetes status and the association to the previous OGTT results was analyzed.Results:The OGTT (0 hours/1 hour/2 hours) results were as follows: healthy subjects: glucose: 94 ± 8 mg/dL/140 ± 29 mg/dL/90 ± 24 mg/dL, intact proinsulin: 3 ± 2 pmol/L/10 ± 7 pmol/L/10 ± 5 pmol/L); IGT: glucose: 102 ± 9 mg/dL/158 ± 57 mg/dL/149 ± 34 mg/dL, intact proinsulin: 7 ± 4 pmol/L/23 ± 8 pmol/L/28 ± 6 pmol/L; T2DM: glucose: 121 ± 20 mg/dL/230 ± 51 mg/dL/213 ± 34 mg/dL; intact proinsulin: 7 ± 7 pmol/L/26 ± 9 pmol/L/27 ± 10 pmol/L). Five years later, all of the IGT and 2 of the healthy subjects had developed T2DM and one had devloped IGT. All of them had elevated 2-hour proinsulin values in the initial OGTT, while patients with normal intact proinsulin results did not develop diabetes.Conclusions:Elevated 2-hour intact proinsulin levels during OGTT were predictive for later type 2 diabetes development. Further studies need to confirm our findings in larger populations.     

Damage Evolution and Life Prediction of Cross-Ply C/SiC Ceramic-Matrix Composite under Cyclic Fatigue Loading at Room Temperature and 800 °C in Air

The damage evolution and life prediction of cross-ply C/SiC ceramic-matrix composite (CMC) under cyclic-fatigue loading at room temperature and 800 °C in air have been investigated using damage parameters derived from fatigue hysteresis loops, i.e., fatigue hysteresis modulus and fatigue hysteresis loss energy. The experimental fatigue hysteresis modulus and fatigue hysteresis loss energy degrade with increasing applied cycles attributed to transverse cracks in the 90° plies, matrix cracks and fiber/matrix interface debonding in the 0° plies, interface wear at room temperature, and interface and carbon fibers oxidation at 800 °C in air. The relationships between fatigue hysteresis loops, fatigue hysteresis modulus and fatigue hysteresis loss energy have been established. Comparing experimental fatigue hysteresis loss energy with theoretical computational values, the fiber/matrix interface shear stress corresponding to different cycle numbers has been estimated. It was found that the degradation rate at 800 °C in air is much faster than that at room temperature due to serious oxidation in the pyrolytic carbon (PyC) interphase and carbon fibers. Combining the fiber fracture model with the interface shear stress degradation model and the fibers strength degradation model, the fraction of broken fibers versus the cycle number can be determined for different fatigue peak stresses. The fatigue life S-N curves of cross-ply C/SiC composite at room temperature and 800 °C in air have been predicted.     

Establishment of a mathematic model for predicting malignancy in solitary pulmonary nodules

Background

The aim of this study was to establish a model for predicting the probability of malignancy in solitary pulmonary nodules (SPNs) and provide guidance for the diagnosis and follow-up intervention of SPNs.

Methods

We retrospectively analyzed the clinical data and computed tomography (CT) images of 294 patients with a clear pathological diagnosis of SPN. Multivariate logistic regression analysis was used to screen independent predictors of the probability of malignancy in the SPN and to establish a model for predicting malignancy in SPNs. Then, another 120 SPN patients who did not participate in the model establishment were chosen as group B and used to verify the accuracy of the prediction model.

Results

Multivariate logistic regression analysis showed that there were significant differences in age, smoking history, maximum diameter of nodules, spiculation, clear borders, and Cyfra21-1 levels between subgroups with benign and malignant SPNs (P<0.05). These factors were identified as independent predictors of malignancy in SPNs. The area under the curve (AUC) was 0.910 [95% confidence interval (CI), 0.857-0.963] in model with Cyfra21-1 significantly better than 0.812 (95% CI, 0.763-0.861) in model without Cyfra21-1 (P=0.008). The area under receiver operating characteristic (ROC) curve of our model is significantly higher than the Mayo model, VA model and Peking University People’s (PKUPH) model. Our model (AUC =0.910) compared with Brock model (AUC =0.878, P=0.350), the difference was not statistically significant.

Conclusions

The model added Cyfra21-1 could improve prediction. The prediction model established in this study can be used to assess the probability of malignancy in SPNs, thereby providing help for the diagnosis of SPNs and the selection of follow-up interventions.     

Human RECQ Helicase Pathogenic Variants,Population Variation and “Missing” Diseases

Heritable loss of function mutations in the human RECQ helicase genes BLM, WRN, and RECQL4 cause Bloom, Werner, and Rothmund‐Thomson syndromes, cancer predispositions with additional developmental or progeroid features. In order to better understand RECQ pathogenic and population variation, we systematically analyzed genetic variation in all five human RECQ helicase genes. A total of 3,741 unique base pair‐level variants were identified, across 17,605 potential mutation sites. Direct counting of BLM, RECQL4, and WRN pathogenic variants was used to determine aggregate and disease‐specific carrier frequencies. The use of biochemical and model organism data, together with computational prediction, identified over 300 potentially pathogenic population variants in RECQL and RECQL5, the two RECQ helicases that are not yet linked to a heritable deficiency syndrome. Despite the presence of these predicted pathogenic variants in the human population, we identified no individuals homozygous for any biochemically verified or predicted pathogenic RECQL or RECQL5 variant. Nor did we find any individual heterozygous for known pathogenic variants in two or more of the disease‐associated RECQ helicase genes BLM, RECQL4, or WRN. Several postulated RECQ helicase deficiency syndromes—RECQL or RECQL5 loss of function, or compound haploinsufficiency for the disease‐associated RECQ helicases—may remain missing, as they likely incompatible with life.     

Extracorporeal photochemotherapy in mycosis fungoides

Objectives

Extracorporeal photo-chemotherapy (ECP, photopheresis) is an approved treatment modality for mycosis fungoides (MF). Our aim is to present our ECP data for MF.

Emerging food allergens: Identification of polyphenol oxidase as an important allergen in eggplant (Solanum melongena L.)

Although many allergens have been detected in eggplant (Solanum melongena L.), their identity have not been elucidated. The aim of this study was to investigate whether polyphenol oxidase (PPO), an important eggplant enzyme, acts as an allergen. The proteins of eggplant peel extract were separated on phenyl-Sepharose (PS), and analyzed by skin prick test (SPT), ELISA and IgE-immunoblotting; the components were analyzed for PPO activity, presence of protein–bound copper, and recognition by rabbit polyclonal anti-sweet potato PPO antiserum. LC–MS/MS and in silico analysis were employed to identify the separated allergens and prediction of IgE epitopes. Eggplant allergens were separated into 5 components (PS1–PS5), of which component PS2 exhibited high specific PPO activity. SPT and ELISA with PPO-rich pool (PS2) were positive in all 6 eggplant-allergic subjects; the 43, 64 and 71 kDa proteins displayed strong IgE-binding ability. The 64 and 71 kDa IgE-binding proteins show PPO activity, presence of copper, and recognition by anti-sweet potato PPO antiserum, clearly identifying them as PPOs; the 43 kDa protein appears to be a degradation product of the 64 or 71 kDa proteins based on enzymic activity and recognition by PPO antiserum. The 64 kDa protein upon further resolution by SDS-PAGE displayed two components (identified as eggplant PPO1 and PPO4 by LC–MS/MS). Based on bioinformatics approaches, PPO4 has been identified as an allergen since it harbors an IgE epitope. This study clearly demonstrates that the 64 and 71 kDa allergens in eggplant peel are PPOs based on enzymic activity and recognition by PPO antiserum; the 64 kDa copper-containing protein is identified as one of the several eggplant allergens (Sola m PPO4). This is the first instance of polyphenol oxidase being identified as a new food allergen.     

Interictal high‐frequency oscillations (HFOs) as predictors of high frequency and conventional seizure onset zones

We investigated the relationship between the interictal high‐frequency oscillations (HFOs) and the seizure onset zones (SOZs) defined by the ictal HFOs or conventional frequency activity (CFA), and evaluated the usefulness of the interictal HFOs as spatial markers of the SOZs. We analysed seizures showing discrete HFOs at onset on intracranial EEGs acquired at ≥1000‐Hz sampling rate in a training cohort of 10 patients with temporal and extratemporal epilepsy. We classified each ictal channel as: HFO+ (HFOs at onset with subsequent evolution), HFO‐ (HFOs at onset without evolution), CFA (1.6–70‐Hz activity at onset with evolution), or non‐ictal. We defined the SOZs as: hSOZ (HFO+ channels only), hfo+&‐SOZ (HFO+ and HFO‐ channels), and cSOZ (CFA channels). Using automated methods, we detected the interictal HFOs and extracted five features: density, connectivity, peak frequency, log power, and amplitude. We created logistic regression models using these features, and tested their performance in a separate replication cohort of three patients. The models containing the five interictal HFO features reliably differentiated the channels located inside the SOZ from those outside in the training cohort (p<0.001), reaching the highest accuracy for the classification of hSOZ. Log power and connectivity had the highest odds ratios, both being higher for the channels inside the SOZ compared with those outside the SOZ. In the replication cohort of novel patients, the same models differentiated the HFO+ from HFO‐ channels, and predicted the extents of the hSOZ and hfo+&‐SOZ (F1 measure >0.5) but not the cSOZ. Our study shows that the interictal HFOs are useful in defining the spatial extent of the SOZ, and predicting whether or not a given channel in a novel patient would be involved in the seizure. The findings support the existence of an abnormal network of tightly‐linked ictal and interictal HFOs in patients with intractable epilepsy.     

Co-delivery of HIF1α siRNA and gemcitabine via biocompatible lipid-polymer hybrid nanoparticles for effective treatment of pancreatic cancer

Hypoxia-inducible factor 1α (HIF1α) has emerged as a promising new target for pancreatic cancer treatment over the past decade. High expression of HIF-1α increases the drug resistance of the current first line chemotherapeutic drug, gemcitabine (Gem). Here we employed biocompatible lipid-polymer hybrid nanoparticles to co-deliver HIF1α siRNA (si-HIF1α) and Gem for pancreatic cancer treatment in subcutaneous and orthotopic tumor models. The cationic ε-polylysine co-polymer (ENPs) can effectively absorb negatively charged si-HIF1α on the surface and encapsulate Gem to the hydrophilic core. Further coating of ENPs with PEGylated lipid bilayer resulted formation of LENPs, with reversed surface charge. The lipid bilayer of LENPs prevented nanoparticle aggregation and si-HIF1α degradation in serum, as well as Gem leakage. Those characteristics endow LENPs encapsulating drug prolonged lifetime in bloodstream and improved drug release via the enhanced tumor vasculature effect in tumor tissues. LENPs can co-deliver Gem and si-HIF1α (LENP-Gem-si-HIF1α) into tumor cells and effectively suppress the HIF1α expression both in vitro and in vivo. LENP-Gem-siHIF1α exhibited significant synergistic antitumor effects. Furthermore, LENP-Gem-si-HIF1α showed excellent capability to inhibit tumor metastasis in orthotopic tumor model.