Collagen/Chitosan Gels Cross-Linked with Genipin for Wound Healing in Mice with Induced Diabetes

Diabetes mellitus continues to be one of the most common diseases often associated with diabetic ulcers. Chitosan is an attractive biopolymer for wound healing due to its biodegradability, biocompatibility, mucoadhesiveness, low toxicity, and hemostatic effect. A panel of hydrogels based on chitosan, collagen, and silver nanoparticels were produced to treat diabetic wounds. The antibacterial activity, cytotoxicity, swelling, rheological properties, and longitudinal sections of hydrogels were studied. The ability of the gels for wound healing was studied in CD1 mice with alloxan-induced diabetes. Application of the gels resulted in an increase in VEGF, TGF-b1, IL-1b, and TIMP1 gene expression and earlier wound closure in a comparison with control untreated wounds. All gels increased collagen deposition, hair follicle repair, and sebaceous glands formation. The results of these tests show that the obtained hydrogels have good mechanical properties and biological activity and have potential applications in the field of wound healing. However, clinical studies are required to compare the efficacy of the gels as animal models do not reproduce full diabetes pathology.     

Improving the Conductivity of the PEDOT:PSS Layers in Photovoltaic Cells Based on Organometallic Halide Perovskites

Among conductive polymers, PEDOT films find the widest application in electronics. For photovoltaic applications, studies of their optical properties, stability, and electrical conductivity are of greatest interest. However, the PEDOT:PSS transport layers, when used in photovoltaic cells, have a high electrical resistance, which prevents solar cells from increasing their efficiency. One of the promising ways to improve their electrical properties is the use of composite materials based on them, in which the conductivity can be increased by introducing various additives. In this work, conductive polymer films PEDOT:PSS (poly (3,4-ethylenedioxythiophene):polystyrene sulfonate acid) doped with a number of amines (Pentylamine, Octylamine, Diethylamine, Aniline with carbon nanotubes) were obtained and studied. It is shown that, depending on the concentration of dopants, the electrical conductivity of PEDOT:PSS films can be significantly improved. In this case, the light transmission of the films practically does not change. The process of improving the conductivity by treating the surface of the finished film with amines, followed by heat treatment, was studied. It is assumed that the improvement in conductivity is the result of the self-assembly of monolayers of organic molecules on the surface of the PEDOT:PSS film leading to its p-doping due to intermolecular interaction.     

Combining E-PASS model and disease specific risk factors to predict severe morbidity after liver and bile duct resection for perihilar cholangiocarcinoma

BackgroundEstimation of physiologic ability and surgical stress system (E-PASS) has been shown to be effective in predicting morbidity after surgery for perihilar cholangiocarcinoma (PHCC). Nevertheless, E-PASS does not include an assessment of the disease specific risk factors. The aim of the study was to estimate the combined impact of E-PASS and specific preoperative factors on major morbidity for PHCC patients.MethodsA retrospective analysis of a prospectively collected data was performed. Severe morbidity according to complication comprehensive index was defined as ≥40 points. A value of comprehensive risk score (CRS) ≥1 was taken as critical.ResultsMultivariate analysis of perioperative data from 122 patients revealed significant impact of five factors (CRS ≥1, future liver remnant volume <50%, T4 stage, moderate and severe cholangitis, INR) on the risk of severe morbidity after resection. The AUC for the combination of these factors was classified as good predictive value (0.810, 95% CI 0.729–0.891) and poor predictive value (0.673, 95% CI 0.573–0.773) for CRS alone (p = 0.040).ConclusionA combination of E-PASS with disease specific risk factors is a reliable predictive model for major morbidity for patients undergoing radical surgery for PHCC.     

Diffusion tensor imaging in schizophrenia.

BACKGROUND: Alignment of white matter axons as inferred from diffusion tensor imaging has indicated changes in schizophrenia in frontal and frontotemporal white matter. METHODS: Diffusion tensor anisotropy and anatomical magnetic resonance images were acquired in 64 patients with schizophrenia and 55 normal volunteers. Anatomical images were acquired with a magnetization prepared rapid gradient echo sequence, and diffusion tensor images used a pulsed gradient spin-echo acquisition. Images were aligned and warped to a standard brain, and anisotropy in normal volunteers and patients was compared using significance probability mapping. RESULTS: Patients showed widespread areas of reduced anisotropy, including the frontal white matter, the corpus callosum, and the frontal longitudinal fasciculus. CONCLUSIONS: These findings, which are consistent with earlier reports of frontal decreases in anisotropy, demonstrate that the effects are most prominent in frontal and callosal areas and are particularly widespread in frontal white matter regions.     

Assessing the prior event rate ratio method via probabilistic bias analysis on a Bayesian network

Background: Unmeasured confounders are commonplace in observational studies conducted using real-world data. Prior event rate ratio (PERR) adjustment is a technique shown to perform well in addressing such confounding. However, it has been demonstrated that, in some circumstances, the PERR method actually increases rather than decreases bias. In this work, we seek to better understand the robustness of PERR adjustment. Methods: We begin with a Bayesian network representation of a generalized observational study, which is subject to unmeasured confounding. Previous work evaluating PERR performance used Monte Carlo simulation to calculate joint probabilities of interest within the study population. Here, we instead use a Bayesian networks framework. Results: Using this streamlined analytic approach, we are able to conduct probabilistic bias analysis (PBA) using large numbers of combinations of parameters and thus obtain a comprehensive picture of PERR performance. We apply our methodology to a recent study that used the PERR in evaluating elderly-specific high-dose (HD) influenza vaccine in the US Veterans Affairs population. That study obtained an HD relative effectiveness of 25% (95% CI: 2%-43%) against influenza- and pneumonia-associated hospitalization, relative to standard-dose influenza vaccine. In this instance, we find that the PERR-adjusted result is more like to underestimate rather than to overestimate the relative effectiveness of the intervention. Conclusions: Although the PERR is a powerful tool for mitigating the effects of unmeasured confounders, it is not infallible. Here, we develop some general guidance for when a PERR approach is appropriate and when PBA is a safer option.     

Fluorescence of radiation-induced tissue damage

Purpose: The aim of this study was evaluating changes in the photosensitizer fluorescence in vivo in the radiation-induced damage area in comparison of intact areas with a simultaneous assessment of changes both in blood parameters and in histological data.

Materials and methods: The study was conducted in white outbred SHK mice (n?=?21). Their right hindlimbs were irradiated with a dose of 25?Gy after the intraperitoneal injections of photosensitizer ‘Photosens’. Fluorescence intensity was traced in vivo by a laser diagnostic system for seven weeks. Simultaneously, histological examination of the damaged areas and blood tests were performed.

Results: An increased intensity of the laser-induced fluorescence of the photosensitizer ‘Photosens’ in the damaged areas, compared to the intact symmetrical ones was observed. Laboratory blood tests and histological examination showed changes that may indicate the occurrence of inflammation.

Conclusion: Enhanced intensity of the exogenous fluorescence of the photosensitizer in the radiation-induced inflammation of noncancerous tissues was observed. The obtained results may potentially affect an interpretation of the results of intraoperative tumors navigation that have been previously irradiated and can be used for selection of an individualized dose fractionation algorithm in radiology.     

Antitumor Responses in the Absence of Toxicity in Solid Tumors by Targeting B7-H3 via Chimeric Antigen Receptor T Cells

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