Optimization of Optical and Mechanical Properties of Real Architecture for 3-Dimensional Tissue Equivalents: Towards Treatment of Limbal Epithelial Stem Cell Deficiency

Limbal epithelial stem cell (LESC) deficiency can cause blindness. Transplantation of cultured human limbal epithelial cells (hLE) on human amniotic membrane (HAM) can restore vision but clinical graft manufacture can be unreliable. We have developed a reliable and robust tissue equivalent (TE) alternative to HAM, Real Architecture for 3D Tissue (RAFT). Here, we aimed to optimize the optical and mechanical properties of RAFT TE for treatment of LESC deficiency in clinical application. The RAFT TE protocol is tunable; varying collagen concentration and volume produces differing RAFT TEs. These were compared with HAM samples taken from locations proximal and distal to the placental disc. Outcomes assessed were transparency, thickness, light transmission, tensile strength, ease of handling, degradation rates and suitability as substrate for hLE culture. Proximal HAM samples were thicker and stronger with poorer optical properties than distal HAM samples. RAFT TEs produced using higher amounts of collagen were thicker and stronger with poorer optical properties than those produced using lower amounts of collagen. The ‘optimal’ RAFT TE was thin, transparent but still handleable and was produced using 0.6 ml of 3 mg/ml collagen. Degradation rates of the ‘optimal’ RAFT TE and HAM were similar. hLE achieved confluency on ‘optimal’ RAFT TEs at comparable rates to HAM and cells expressed high levels of putative stem cell marker p63α. These findings support the use of RAFT TE for hLE transplantation towards treatment of LESC deficiency

Cadaveric renal transplantation under cyclosporine-steroid therapy

Ninety-seven cadaveric renal transplants were performed upon 96 patients during 1981. The one year patient mortality was 2.1 per cent. Seventy of the recipients were undergoing trasplantation for the first time. Of these patients, 38 were treated with cyclosporine and steroids with a one year graft survival rate of 89.5 per cent. The other 32 primary recipients were treated with azathioprine and steroids with a one year graft survival rate of 50 per cent. The difference between the cyclosporine-steroid versus conventional therapy groups was significant. Cyclosporine and steroids were also used to treat 26 patients who underwent retransplantation with 27 cadaveric grafts. The one year graft survival time was 77.8 per cent; most of the graft losses were in presensitized patients. The results with retransplantation were twice as good as in historical control groups

Variable convalescence and therapy after cadaveric renal transplantation under cyclosporin A and steroids

The postoperative convalescence period was analyzed for 42 consecutive patients who had cadaveric renal transplantation under therapy with cyclosporin A and steroids. Twenty-two of the patients underwent transplantation for the first time, and the other 20 had retransplantation. None of the recipients has died. With follow-up period of two to eight months, the survival rate of grafts is 96 per cent after first transplantation and 85 per cent after retransplantation. Immunosuppression with a standard regimen was used for all patients at the outset. Early convalescence was highly variable, often necessitating adjustments of cyclosporin A and steroid dosage to accommodate the possibilities of rejection or cyclosporin A nephrotoxicity, or both, simultaneously. Management problems were more frequent and complex in patients undergoing retransplantation. From the results, a classification of convalescence patterns was evolved, with recommendations about how standardized initial therapy should be adjusted if the renal graft does not function promptly or deteriorates later

The interaction between diabetes, body mass index, hepatic steatosis, and risk of liver resection: insulin dependent diabetes is the greatest risk for major complications

Background. This study aimed to assess the relationship between diabetes, obesity, and hepatic steatosis in patients undergoing liver resection and to determine if these factors are independent predictors of major complications. Materials and Methods. Analysis of a prospectively maintained database of patients undergoing liver resection between 2005 and 2012 was undertaken. Background liver was assessed for steatosis and classified as <33% and ≥33%. Major complications were defined as Grade III–V complications using theindo-Clavien classification. Results. 504 patients underwent liver resection, of whom 56 had diabetes and 61 had steatosis ≥33%. Median BMI was 26kg/m2 (16–54kg/m 2). 94 patients developed a major complication (18.7%). BMI ≥ 25kg/m2

The living aortic valve: From molecules to function.

The aortic valve lies in a unique hemodynamic environment, one characterized by a range of stresses (shear stress, bending forces, loading forces and strain) that vary in intensity and direction throughout the cardiac cycle. Yet, despite its changing environment, the aortic valve opens and closes over 100,000 times a day and, in the majority of human beings, will function normally over a lifespan of 70-90 years. Until relatively recently heart valves were considered passive structures that play no active role in the functioning of a valve, or in the maintenance of its integrity and durability. However, through clinical experience and basic research the aortic valve can now be characterized as a living, dynamic organ with the capacity to adapt to its complex mechanical and biomechanical environment through active and passive communication between its constituent parts. The clinical relevance of a living valve substitute in patients requiring aortic valve replacement has been confirmed. This highlights the importance of using tissue engineering to develop heart valve substitutes containing living cells which have the ability to assume the complex functioning of the native valve

De Novo Genome Sequence of "Candidatus Liberibacter solanacearum" from a Single Potato Psyllid in California.

The draft genome sequence of "Candidatus Liberibacter solanacearum" strain RSTM from a potato psyllid (Bactericera cockerelli) in California is reported here. The RSTM strain has a genome size of 1,286,787 bp, a G+C content of 35.1%, 1,211 predicted open reading frames (ORFs), and 43 RNA genes

Efficient Multi-Robot Motion Planning for Unlabeled Discs in Simple Polygons

We consider the following motion-planning problem: we are given $m$ unit discs in a simple polygon with $n$ vertices, each at their own start position, and we want to move the discs to a given set of $m$ target positions. Contrary to the standard (labeled) version of the problem, each disc is allowed to be moved to any target position, as long as in the end every target position is occupied. We show that this unlabeled version of the problem can be solved in $O(n\log n+mn+m^2)$ time, assuming that the start and target positions are at least some minimal distance from each other. This is in sharp contrast to the standard (labeled) and more general multi-robot motion-planning problem for discs moving in a simple polygon, which is known to be strongly NP-hard

Particle creation rate for dynamical black holes

We present the particle creation probability rate around a general black hole as an outcome of quantum fluctuations. Using the uncertainty principle for these fluctuation, we derive a new ultraviolet frequency cutoff for the radiation spectrum of a dynamical black hole. Using this frequency cutoff, we define the probability creation rate function for such black holes. We consider a dynamical Vaidya model, and calculate the probability creation rate for this case when its horizon is in a slowly evolving phase. Our results show that one can expect the usual Hawking radiation emission process in the case of a dynamical black hole when it has a slowly evolving horizon. Moreover, calculating the probability rate for a dynamical black hole gives a measure of when Hawking radiation can be killed off by an incoming flux of matter or radiation. Our result strictly suggests that we have to revise the Hawking radiation expectation for primordial black holes that have grown substantially since they were created in the early universe. We also infer that this frequency cut off can be a parameter that shows the primordial black hole growth at the emission moment.Comment: 10 pages, 1 figure. The paper was rewritten in more clear presentation and one more appendix is adde