Portal vein thrombosis after intraportal hepatocytes transplantation in a liver transplant recipient

Hepatocytes transplantation is viewed as a possible alternative or as a bridge therapy to liver transplantation for patients affected by acute or chronic liver disorders. Very few data regarding complications of hepatocytes transplantation is available from the literature. Herein we report for the first time a case of portal vein thrombosis after intraportal hepatocytes transplantation in a liver transplant recipient. A patient affected by acute graft dysfunction, not eligible for retransplantation, underwent intraportal infusion of 2 billion viable cryopreserved ABO identical human allogenic hepatocytes over a period of 5 h. Hepatocytes were transplanted at a concentration of 14 million/ml for a total infused volume of 280 ml. Doppler portal vein ultrasound and intraportal pressure were monitored during cell infusion. The procedure was complicated, 8 h after termination, by the development of portal vein thrombosis with liver failure and death of the patient. Autopsy showed occlusive thrombosis of the intrahepatic portal vein branches; cells or large aggregates of epithelial elements (polyclonal CEA positive), suggestive for transplanted hepatocytes, were co-localized inside the thrombus.     

In vitro cartilage regeneration from proliferated adult elastic chondrocytes

The purpose of this study was to investigate cellular feasibility in the proliferation and differentiation status of adult chondrocytes for cartilage regeneration in comparison to fetal chondrocytes. Primary cells were isolated from adult (n = 6) and fetal (n = 6) sheep ear cartilages and expanded in 10% fetal bovine serum (FBS) containing Ham's F12 medium, in which adult and fetal cell proliferation rates were compared using a WST-1 assay kit. Approximately 4 million cells were seeded onto each 1 x 1 x 0.2-cm (200 microL) nonwoven fabric scaffold made from polyglycolic acid. Cell/polymer constructs were cultured in serum-free DMEM/F12 medium supplemented with 5 ng/mL TGF-beta2 and 5 ng/mL des(1-3)IGF-I (adult chondrocytes, group A) or in 10% FBS containing Ham's F12 medium (adult chondrocytes, group B, and fetal chondrocytes, group C) as controls in a rotating bioreactor for 6 weeks. The proliferation assay showed that fetal cells had a significantly better growth potential than did adult cells. Histology and extracellular matrix analyses revealed that groups A and C qualitatively displayed better matrix deposition than did group B. In conclusion, although adult sheep elastic chondrocytes had less growth potential than did fetal cells, the serum-free medium supplemented with growth factors significantly enhanced the production of cartilage matrix secreted from proliferated adult sheep elastic chondrocytes.     

Preferential Liver Accumulation of Mercury Explains Low Concentrations in Muscle of Caiman yacare (Alligatoridae) in Upper Amazon

Caiman yacare is considered one of the top predators in the Amazon basin, and understanding pollutant distribution within its tissues may help its sustainable management. As a top predator, C. yacare should have the highest mercury concentrations, but has lower Hg concentrations than carnivorous fish (Rivera et al. 2016), which are part of their diet. We compared total Hg among liver, kidney, fat, and muscle of C. yacare, and whether trends in the distribution of Hg among tissues were like other crocodilians, aquatic birds, omnivorous, and carnivorous fish. Fat had the lowest concentrations (0.025 ± 0.03 mg kg⁻¹) followed by muscle (0.15 ± 0.06 mg kg⁻¹), kidney (0.57 ± 0.30 mg kg⁻¹) and liver (1.81 ± 0.80 mg kg⁻¹). Such preferential accumulation makes C. yacare meat a safer alternative for human consumption than carnivorous fish. The relation between Hg accumulation in liver and muscle is highest in crocodilians, which has evolutive and environmental implications.

     

Multiple fragments of human TG are capable of inducing oral tolerance to whole human TG

Oral tolerance is the mechanism by which the immune system remains unresponsive to orally administered soluble antigens. Mice immunized with human TG (hTG), resulting in the induction of experimental autoimmune thyroiditis (EAT), provide an ideal in vivo system in which to examine oral tolerance to hTG. In the present study, we characterize epitopes of hTG that are capable of inducing oral tolerance. hTG is a large homodimeric protein, 660 Kd. The limited proteolysis of hTG using trypsin (TR) generates several smaller fragments of hTG ranging in size from 29 Kd to 145 Kd. Using hTG fragments h1TR (residues 1-521), h4bisTR (residues 2513-2713), h6TR (residues 522-1626), and h7TR (residues 1627-2512), prepared from both iodine rich and iodine poor hTG, we investigated the ability of these fragments to induce oral tolerance. The oral administration of iodine rich h6TR or h7TR suppresses hTG specific immune responses in a manner similar to whole hTG. In contrast, the oral administration of iodine rich h1TR or h4bisTR exacerbates hTG specific immune responses. Unlike iodine rich h1TR or h4bisTR, the oral administration of iodine poor h1TR or h4bisTR fails to augment hTG specific immune responses. In fact, h4bisTR suppresses hTG specific immune responses. These results indicate that hTG contains multiple epitopes that differentially affect oral tolerization. Tolerogenic epitopes reside within fragments h6TR and h7TR. The removal of iodine, and presumably hormone, from h4bisTR converts an immunogenic epitope to a tolerogenic epitope.     

Assessment programs to enhance learning

Background: Assessment is an essential part of the educational system. Usually, assessment is used to measure students’ knowledge, but it can also be used to drive students’ learning and behaviors. Assessment programs should be constructed in a well-balanced way allowing not only measuring students’ knowledge but also changing students’ behavior.

Objectives: In this paper, we will discuss different strategies that can be used to change students’ behaviors which may improve their learning.

Main findings: Assessment as well as the learning material should be congruent with the objectives. Based on the literature, we summarize findings that would address key points to allow assessment for learning instead of learning.

Conclusions: When constructing an assessment program, choices have to be made that depend on aspects like logistics, financial, organizational, managerial, educational culture, and cooperation of individual and key faculty members. It is important to realize that whatever decisions you make, students will always adapt their behavior to the way you construct your assessment program.     

Incidental findings in multislice computed tomography prior to transcatheter aortic valve implantation: frequency,clinical relevance and outcome

Multislice computed tomography (MSCT) has emerged as the mainstay in patients planned for transcatheter aortic valve implantation (TAVI). Incidental findings (IF) in MSCT are common. However, the exact incidence, clinical relevance and further consequences of IF are unclear and it is controversial whether IF adversely affect patients’ outcome. We analyzed MSCT data of 1050 patients screened for TAVI between January 2011 and December 2014. Median follow-up of patients was 20 months. In total, 3194 IF were identified, which were classified into clinically non-relevant IF (2872, 90%) and clinically relevant IF (322, 10%). In 25% of patients (258/1050) at least one clinically relevant IF was present. Age (80?±?7 vs. 80?±?7 years; p?=?0.198) and EuroSCORE II (3.6% [2.1–5.7] vs. 3.6% [2.1–5.9]; p?=?0.874) was similar between patients with and without a clinically relevant IF. TAVI was performed less frequently in patients with a clinically relevant IF (76% vs. 85%; p?<?0.001), with more patients receiving surgical aortic valve replacement in that group (14% vs. 11%; p?=?0.042), possibly due to the high rate of incidental aneurysms of the ascending aorta (n?=?48). If TAVI was performed mortality did not differ (30-days: 4% vs. 3%; p?=?0.339, 1-year: 11% vs. 14%; p?=?0.226) between patients with and without a clinically relevant IF. Our study is the largest study to analyze prevalence, clinical relevance and therapeutic consequences of IF during screening for TAVI. IF in pre-procedural MSCT are common and clinically relevant in one-quarter of patients. However, these findings had no impact on overall mortality.