A Mathematical Morphology Approach to Cell Shape Analysis

This contribution aims to apply mathematical morphology operators to quantify the shape of round-objects which present irregularities from an ideal circular pattern. More specifically we illustrate, on the one hand, the application of morphological granulometries for size/shape multi-scale description and on the other hand, the radial/angular decompo- sitions using skeletons in polar-logarithmic representation. We discuss also the aspects related to the properties of invariance of these tools, which is important to describe cell shapes acquired under different magnifications, orientations, etc

A General Inverse Problem for the Growth-Fragmentation Equation

The growth-fragmentation equation arises in many different contexts, ranging from cell division, protein polymerization, biopolymers, neurosciences etc. Direct observation of temporal dynamics being often difficult, it is of main interest to develop theoretical and numerical methods to recover reaction rates and parameters of the equation from indirect observation of the solution. Following the work done in (Perthame, Zubelli, 2006) and (Doumic, Perthame, Zubelli, 2009) for the specific case of the cell division equation, we address here the general question of recovering the fragmentation rate of the equation from the observation of the time-asymptotic solution, when the fragmentation kernel and the growth rates are fully general. We give both theoretical results and numerical methods, and discuss the remaining issues

Sheldon Spectrum and the Plankton Paradox: Two Sides of the Same Coin : A trait-based plankton size-spectrum model

The Sheldon spectrum describes a remarkable regularity in aquatic ecosystems: the biomass density as a function of logarithmic body mass is approximately constant over many orders of magnitude. While size-spectrum models have explained this phenomenon for assemblages of multicellular organisms, this paper introduces a species-resolved size-spectrum model to explain the phenomenon in unicellular plankton. A Sheldon spectrum spanning the cell-size range of unicellular plankton necessarily consists of a large number of coexisting species covering a wide range of characteristic sizes. The coexistence of many phytoplankton species feeding on a small number of resources is known as the Paradox of the Plankton. Our model resolves the paradox by showing that coexistence is facilitated by the allometric scaling of four physiological rates. Two of the allometries have empirical support, the remaining two emerge from predator-prey interactions exactly when the abundances follow a Sheldon spectrum. Our plankton model is a scale-invariant trait-based size-spectrum model: it describes the abundance of phyto- and zooplankton cells as a function of both size and species trait (the maximal size before cell division). It incorporates growth due to resource consumption and predation on smaller cells, death due to predation, and a flexible cell division process. We give analytic solutions at steady state for both the within-species size distributions and the relative abundances across species

Experiences of living with MRSA - a literature review

Meticillinresistenta staphylococcus aureus (MRSA) är en allmänfarlig smitta med anmälningsplikt i Sverige. Nationellt är förekomsten låg, globalt högre. I omvårdnad är kommunikation en grundbult och genom att kommunicera med patienten kan sjuksköterskan förstå omvårdnadsbehoven, lära känna patienten och nå omvårdnadsmålen. Information kan vara ett behov inom omvårdnad vilket kräver kommunikation. Individens upplevelse definieras som medvetande om något och vad något är. Känslan av sammanhang (KASAM) påverkar individens grad av upplevd hälsa. Hög grad av KASAM är baserat på hög meningsfullhet, begriplighet och hanterbarhet och leder till hög grad av hälsa. Samtliga delar påverkas av sjuksköterskans bemötande som kan utgå från personcentrerad vård vilket har fokus på livsberättelse, partnerskap och dokumentation. Syftet med studien var att belysa patienters upplevelser av att leva med MRSA. Metoden som användes var litteraturöversikt baserat på analys av en kvantitativ och nio kvalitativa artiklar. Resultatet delades in i fem teman; Psykisk påverkan som främst bestod av upplevelser som psykologiskt trauma, pestsmittad samt oro och rädsla över att smitta andra. Det fanns dock patienter som upplevde optimism och hopp; Livsförändringar beskrev fysiska symtom, förändrat praktiskt handlande där hygienen tog stor plats, begränsat vardagsliv samt rädsla och oro från omgivningen; Vårdmöten visade på bristande kunskap hos personal och att vårdtiden kännetecknades av stigmatisering och dåligt bemötande; Isolering upplevdes begränsande, umgänget med andra samt vårdkvalitén påverkades; Information och kunskap fanns behov och önskemål om och upplevdes ofta som otillräcklig. Patientens KASAM skulle kunna påverkas av psykisk påverkan, förändrat praktiskt handlande, bristande bemötande och informationstillgång. Genom personcentrerad vård kan sjuksköterskan hjälpa patienten till ökad acceptans och välbefinnande

Targeting adenovirus gene delivery to activated tumour-associated vasculature via endothelial selectins.

Clinical experience with adenovirus vectors has highlighted the need for improved delivery and targeting. Tumour-associated endothelium offers an additional mechanism for enhanced viral uptake into tumours which is accessible for systemic gene delivery. Building on expertise in using polymer 'stealthed' viruses for targeting in vivo, adenovirus expressing luciferase (Adluc) was coated with an amino-reactive polymer based on poly [N-(2-hydroxypropyl) methacrylamide] to ablate normal infection pathways. Direct linkage of a monoclonal antibody against E-selectin (MHES) demonstrated E-selectin-specific transduction of tumour necrosis factor-α (TNF-α)-activated endothelial cells. A two-component targeting system using protein G was developed, to provide optimal antibody orientation. We report an enhancement in transduction of TNF-α-activated endothelium in vitro and ex vivo in a human umbilical vein cord model using the MHES antibody. Similarly a virus retargeted using a chimeric P-selectin Glycoprotein Ligand-1-Fc fusion (PSGL-1) protein showed better circulation kinetics and significant uptake into HepG2 xenografts following systemic administration in mice, with 36-fold higher genome copies, compared with non-modified virus. Immunohistochemistry staining of tumour sections from mice treated with PSGL-1-retargeted virus showed a co-localisation of firefly luciferase with CD31 suggesting selective endothelial targeting. Employment of optimal viral modification using protein G will enable exploration and comparison of alternative targeting ligands targeting tumour-associated endothelium