Prognostic factors for survival in patients with colorectal liver metastases: experience of a single brazilian cancer center

CONTEXT: Liver metastases are a common event in the clinical outcome of patients with colorectal cancer and account for 2/3 of deaths from this disease. There is considerable controversy among the data in the literature regarding the results of surgical treatment and prognostic factors of survival, and no analysis have been done in a large cohort of patients in Brazil. OBJECTIVES: To characterize the results of surgical treatment of patients with colorectal liver metastases, and to establish prognostic factors of survival in a Brazilian population. METHOD: This was a retrospective study of patients undergoing liver resection for colorectal metastases in a tertiary cancer hospital from 1998 to 2009. We analyzed epidemiologic variables and the clinical characteristics of primary tumors, metastatic disease and its treatment, surgical procedures and follow-up, and survival results. Survival analyzes were done by the Kaplan-Meier method and the log-rank test was applied to determine the influence of variables on overall and disease-free survival. All variables associated with survival with P<0.20 in univariate analysis, were included in multivariate analysis using a Cox proportional hazard regression model. RESULTS: During the period analyzed, 209 procedures were performed on 170 patients. Postope-rative mortality in 90 days was 2.9% and 5-year overall survival was 64.9%. Its independent prognostic factors were the presence of extrahepatic disease at diagnosis of liver metastases, bilateral nodules and the occurrence of major complications after liver surgery. The estimated 5-year disease-free survival was 39.1% and its prognostic factors included R1 resection, extrahepatic disease, bilateral nodules, lymph node involvement in the primary tumor and primary tumors located in the rectum. CONCLUSION: Liver resection for colorectal metastases is safe and effective and the analysis of prognostic factors of survival in a large cohort of Brazilian patients showed similar results to those pointed in international series. The occurrence of major postoperative complications appears to be able to compromise overall survival and further investigation in needed in this topic.

In vitro schistosomicidal effects of the essential oil of Tagetes erecta

The in vitro schistosomicidal effects of the essential oil obtained from Tagetes erecta L. Asteraceae, leaves (TE-EO) collected in Brazil against Schistosoma mansoni worms are reported in this paper. The oil caused a significant decrease in the motor activity at 50 µg/mL as minimal concentration after 24 h. This oil also caused death of all the parasites and the separation of coupled pairs into individual male and female at 100 µg/mL after 24 h. The viability of adult worm groups treated with the TE-EO at 100 µg/mL was similar to that of groups treated with praziquantel (positive control). In addition, the oil promoted the inhibition of eggs development at all the tested concentrations. These data indicate that the TE-EO could be considered as a promising source for the development of new schistosomicidal agents.

Assessment of metabolic control among patients in a capillary glucose self-monitoring program

OBJECTIVE: To assess the metabolic control of diabetes mellitus patients registered in a capillary glucose self-monitoring program at home. METHODS: In this longitudinal retrospective study, 97 subjects at four health institutions in a Brazilian city were followed during 37 months between 2005 and 2008. The health files were analyzed of patients selected to register the evolution of variables related to capillary glucose self-monitoring at home and metabolic control of diabetes mellitus. RESULTS: During the assessment, both mean and monthly percentages of capillary blood glucose measurements at home decreased from 34.1 (65.1%) to 33.6 (64.8%), respectively (p <0.001). Mean HbA1c levels dropped from 9.20% to 7.94% (p<0.001). HDL cholesterol decreased from 51 mg/dl to 47 mg/dl (p=0.001). CONCLUSION: Patients' metabolic control improved, characterized by a significant reduction in HbA1C.

A new species of Hydrogamasellus (Acari: Mesostigmata: Ologamasidae) from Brazil, with a key to the world species of the genus

Hydrogamasellus alagoensis n. sp. is described based on the morphology of adult females and males collected from litter in the State of Alagoas, Brazil. Six new combinations are proposed, namely Acugamasus avium (Karg, 1976) n. comb., Ologamasus lanceolatus (Karg, 1976) n. comb., Ologamasus microcrinis (Karg, 1979) n. comb., Ologamasus testudinis (Karg, 1976) n. comb., Rykellus longopilus (Karg, 1976) n. comb. and Rykellus ubatubaensis (Hirschmann, 1966) n. comb., and a key for the separation of females of the eighteen recognizable world Hydrogamasellus species is provided.

Inhibition of human platelet aggregation by eosinophils

AIMS: The relationship between the activity of eosinophils and platelets has been observed in recent decades by many scientists. These observations include increased numbers of eosinophils associated with platelet disorders, including changes in the coagulation cascade and platelet aggregation. Based on these observations, the interaction between eosinophils and platelets in platelet aggregation was analyze. MAIN METHODS: Human platelets were incubated with eosinophil cytosolic fraction, promyelocytic human HL-60 clone 15 cell lineage, and eosinophil cationic protein (ECP). Platelet rich plasma (PRP) aggregation was induced by adenosine diphosphate, platelet activating factor, arachidonic acid, and collagen, and washed platelets (WP) were activated by thrombin. KEY FINDINGS: Aggregation induced by all agonists was dose dependently inhibited by eosinophil cytosolic fraction. This inhibition was only partially reversed by previous incubation of the eosinophils with l-Nitro-Arginine-Methyl-Ester (l-NAME). Previous incubation with indomethacin did not prevent the cytosolic fraction induced inhibition. The separation of eosinophil cytosolic fraction by gel filtration on Sephadex G-75 showed that the inhibitory activity was concentrated in the lower molecular weight fraction. HL-60 clone 15 cells differentiated into eosinophils for 5 and 7 day were able to inhibit platelet aggregation. The ECP protein inhibited the platelet aggregation on PRP and WP. This inhibition was more evident in WP, and the citotoxicity MTT assay proved the viability of tested platelets, showing that the observed inhibition by the ECP protein does not occur simply by cell death. SIGNIFICANCE: Our results indicate that eosinophils play a fundamental role in platelet aggregation inhibition

Food safety in wine: optimization of analytical controls and evaluation of production technologies

This PhD thesis has been proposed to validate and then apply innovative analytical methodologies for the determination of compounds with harmful impact on human health, such as biogenic amines and ochratoxin A in wines. Therefore, the influence of production technology (pH, amino acids precursor and use of different malolactic starters) on biogenic amines content in wines was evaluated. An HPLC method for simultaneous determination of amino acids and amines with precolumnderivatization with 9-Fluorenyl-methoxycarbonyl chloride (FMOC-Cl) and UV detection was developed. Initially, the influence of pH, time of derivatization, gradient profile were studied. In order to improve the separation of amino acids and amines and reduce the time of analysis, it was decided to study the influence of different flows and the use of different columns in the chromatographic method. Firstly, a C18 Luna column was used and later two monolithic columns Chromolith in series. It appeared to be suitable for an easy, precise and accurate determination of a relatively large number of amino acids and amines in wines. This method was then applied on different wines produced in the Emilia Romagna region. The investigation permitted to discriminate between red and white wines. Amino acids content is related to the winemaking process. Biogenic amines content in these wines does not represent a possible toxicological problem for human health. The results of the study of influence of technologies and wine composition demonstrated that pH of wines and amino acids content are the most important factors. Particularly wines with pH > 3,5 show higher concentration of biogenic amines than wines with lower pH. The enrichment of wines by nutrients also influences the content of some biogenic amines that are higher in wines added with amino acids precursors. In this study, amino acids and biogenic amines are not statistically affected by strain of lactic acid bacteria inoculated as a starter for malolactic fermentation. An evaluation of different clean-up (SPE-MycoSep; IACs and LLE) and determination methods (HPLC and ELISA) of ochratoxin A was carried out. The results obtained proved that the SPE clean-up are reliable at the same level while the LLE procedures shows lowest recovery. The ELISA method gave a lower determination and a low reproducibility than HPLC method.

Study of the thermal effects induced by magnetic resonance on endocardial leads: numerical models and experimental validation

Magnetic resonance imaging (MRI) is today precluded to patients bearing active implantable medical devices AIMDs). The great advantages related to this diagnostic modality, together with the increasing number of people benefiting from implantable devices, in particular pacemakers(PM)and carioverter/defibrillators (ICD), is prompting the scientific community the study the possibility to extend MRI also to implanted patients. The MRI induced specific absorption rate (SAR) and the consequent heating of biological tissues is one of the major concerns that makes patients bearing metallic structures contraindicated for MRI scans. To date, both in-vivo and in-vitro studies have demonstrated the potentially dangerous temperature increase caused by the radiofrequency (RF) field generated during MRI procedures in the tissues surrounding thin metallic implants. On the other side, the technical evolution of MRI scanners and of AIMDs together with published data on the lack of adverse events have reopened the interest in this field and suggest that, under given conditions, MRI can be safely performed also in implanted patients. With a better understanding of the hazards of performing MRI scans on implanted patients as well as the development of MRI safe devices, we may soon enter an era where the ability of this imaging modality may be more widely used to assist in the appropriate diagnosis of patients with devices. In this study both experimental measures and numerical analysis were performed. Aim of the study is to systematically investigate the effects of the MRI RF filed on implantable devices and to identify the elements that play a major role in the induced heating. Furthermore, we aimed at developing a realistic numerical model able to simulate the interactions between an RF coil for MRI and biological tissues implanted with a PM, and to predict the induced SAR as a function of the particular path of the PM lead. The methods developed and validated during the PhD program led to the design of an experimental framework for the accurate measure of PM lead heating induced by MRI systems. In addition, numerical models based on Finite-Differences Time-Domain (FDTD) simulations were validated to obtain a general tool for investigating the large number of parameters and factors involved in this complex phenomenon. The results obtained demonstrated that the MRI induced heating on metallic implants is a real risk that represents a contraindication in extending MRI scans also to patient bearing a PM, an ICD, or other thin metallic objects. On the other side, both experimental data and numerical results show that, under particular conditions, MRI procedures might be consider reasonably safe also for an implanted patient. The complexity and the large number of variables involved, make difficult to define a unique set of such conditions: when the benefits of a MRI investigation cannot be obtained using other imaging techniques, the possibility to perform the scan should not be immediately excluded, but some considerations are always needed.

Length scales of dynamic heterogeneities of low and high molecular weight glass formers from multidimensional NMR

Das Ziel der vorliegenden Arbeit ist die Untersuchung der räumlichen und zeitlichen Aspekte der heterogenen Dynamik in Modellglasbildnern. Dabei wird vor allem die langsame alpha-Relaxationsdynamik oberhalb des Glasüberganges Tg untersucht. Die nukleare Magnetresonanz zeigt ihre einmalige Vielseitigkeit bei der Untersuchung molekularer Dynamik, wenn die angewandten Techniken und Experimente durch Simulationen unterstützt werden. Die räumliche Aspekt dynamischer Heterogenitäten wird untersucht durch ein reduziertes vierdimensionales Spindiffusionsexperiment (4D3CP), ein Experiment, das Reorientierungsraten örtlich korreliert. Eine Simulation dieses Experimentes an einem System harter Kugeln liefert wertvolle Informationen über die Auswertemethode des 4D3CP Experiments. Glycerol und o-terphenyl werden durch das 4D3CP Experiment untersucht. Die erhaltenen Resultate werden mit bereits publizierten Daten des polymeren Glasbildners PVAc verglichen. Während PVAc und o-terphenyl eine Längenskale von 3.7 nm bzw. 2.9 nm aufweisen, ist die Längenskale von Glycerol signifikant kleiner bei 1.1 nm. Ein neues Experiment, welches sensitiv auf Translationsbewegung reagiert, wird vorgestellt. Durch Verwendung eines pi-Impulszuges kann eine separate Evolution unter dem Hamiltonian der dipolaren Kopplung und der chemischen Verschiebungsanisotropie erreicht werden.

An evolutionary approach to the design of experiments for combinatorial optimization with an application to enzyme engineering

In a large number of problems the high dimensionality of the search space, the vast number of variables and the economical constrains limit the ability of classical techniques to reach the optimum of a function, known or unknown. In this thesis we investigate the possibility to combine approaches from advanced statistics and optimization algorithms in such a way to better explore the combinatorial search space and to increase the performance of the approaches. To this purpose we propose two methods: (i) Model Based Ant Colony Design and (ii) Naïve Bayes Ant Colony Optimization. We test the performance of the two proposed solutions on a simulation study and we apply the novel techniques on an appplication in the field of Enzyme Engineering and Design.

Decomposition and reformulation of integer linear programming problems

This thesis deals with an investigation of Decomposition and Reformulation to solve Integer Linear Programming Problems. This method is often a very successful approach computationally, producing high-quality solutions for well-structured combinatorial optimization problems like vehicle routing, cutting stock, p-median and generalized assignment . However, until now the method has always been tailored to the specific problem under investigation. The principal innovation of this thesis is to develop a new framework able to apply this concept to a generic MIP problem. The new approach is thus capable of auto-decomposition and autoreformulation of the input problem applicable as a resolving black box algorithm and works as a complement and alternative to the normal resolving techniques. The idea of Decomposing and Reformulating (usually called in literature Dantzig and Wolfe Decomposition DWD) is, given a MIP, to convexify one (or more) subset(s) of constraints (slaves) and working on the partially convexified polyhedron(s) obtained. For a given MIP several decompositions can be defined depending from what sets of constraints we want to convexify. In this thesis we mainly reformulate MIPs using two sets of variables: the original variables and the extended variables (representing the exponential extreme points). The master constraints consist of the original constraints not included in any slaves plus the convexity constraint(s) and the linking constraints(ensuring that each original variable can be viewed as linear combination of extreme points of the slaves). The solution procedure consists of iteratively solving the reformulated MIP (master) and checking (pricing) if a variable of reduced costs exists, and in which case adding it to the master and solving it again (columns generation), or otherwise stopping the procedure. The advantage of using DWD is that the reformulated relaxation gives bounds stronger than the original LP relaxation, in addition it can be incorporated in a Branch and bound scheme (Branch and Price) in order to solve the problem to optimality. If the computational time for the pricing problem is reasonable this leads in practice to a stronger speed up in the solution time, specially when the convex hull of the slaves is easy to compute, usually because of its special structure.

Definition, realization and evaluation of a software reference architecture for use in space applications

A recent initiative of the European Space Agency (ESA) aims at the definition and adoption of a software reference architecture for use in on-board software of future space missions. Our PhD project placed in the context of that effort. At the outset of our work we gathered all the industrial needs relevant to ESA and all the main European space stakeholders and we were able to consolidate a set of technical high-level requirements for the fulfillment of them. The conclusion we reached from that phase confirmed that the adoption of a software reference architecture was indeed the best solution for the fulfillment of the high-level requirements. The software reference architecture we set on building rests on four constituents: (i) a component model, to design the software as a composition of individually verifiable and reusable software units; (ii) a computational model, to ensure that the architectural description of the software is statically analyzable; (iii) a programming model, to ensure that the implementation of the design entities conforms with the semantics, the assumptions and the constraints of the computational model; (iv) a conforming execution platform, to actively preserve at run time the properties asserted by static analysis. The nature, feasibility and fitness of constituents (ii), (iii) and (iv), were already proved by the author in an international project that preceded the commencement of the PhD work. The core of the PhD project was therefore centered on the design and prototype implementation of constituent (i), a component model. Our proposed component model is centered on: (i) rigorous separation of concerns, achieved with the support for design views and by careful allocation of concerns to the dedicated software entities; (ii) the support for specification and model-based analysis of extra-functional properties; (iii) the inclusion space-specific concerns.

Radiochemical aspects of production and processing of radiometals for preparation of metalloradiopharmaceuticals

Radiometals play an important role in nuclear medicine as involved in diagnostic or therapeutic agents. In the present work the radiochemical aspects of production and processing of very promising radiometals of the third group of the periodic table, namely radiogallium and radiolanthanides are investigated. The 68Ge/68Ga generator (68Ge, T½ = 270.8 d) provides a cyclotron-independent source of positron-emitting 68Ga (T½ = 68 min), which can be used for coordinative labelling. However, for labelling of biomolecules via bifunctional chelators, particularly if legal aspects of production of radiopharmaceuticals are considered, 68Ga(III) as eluted initially needs to be pre-concentrated and purified. The first experimental chapter describes a system for simple and efficient handling of the 68Ge/68Ga generator eluates with a cation-exchange micro-chromatography column as the main component. Chemical purification and volume concentration of 68Ga(III) are carried out in hydrochloric acid – acetone media. Finally, generator produced 68Ga(III) is obtained with an excellent radiochemical and chemical purity in a minimised volume in a form applicable directly for the synthesis of 68Ga-labelled radiopharmaceuticals. For labelling with 68Ga(III), somatostatin analogue DOTA-octreotides (DOTATOC, DOTANOC) are used. 68Ga-DOTATOC and 68Ga-DOTANOC were successfully used to diagnose human somatostatin receptor-expressing tumours with PET/CT. Additionally, the proposed method was adapted for purification and medical utilisation of the cyclotron produced SPECT gallium radionuclide 67Ga(III). Second experimental chapter discusses a diagnostic radiolanthanide 140Nd, produced by irradiation of macro amounts of natural CeO2 and Pr2O3 in natCe(3He,xn)140Nd and 141Pr(p,2n)140Nd nuclear reactions, respectively. With this produced and processed 140Nd an efficient 140Nd/140Pr radionuclide generator system has been developed and evaluated. The principle of radiochemical separation of the mother and daughter radiolanthanides is based on physical-chemical transitions (hot-atom effects) of 140Pr following the electron capture process of 140Nd. The mother radionuclide 140Nd(III) is quantitatively absorbed on a solid phase matrix in the chemical form of 140Nd-DOTA-conjugated complexes, while daughter nuclide 140Pr is generated in an ionic species. With a very high elution yield and satisfactory chemical and radiolytical stability the system could able to provide the short-lived positron-emitting radiolanthanide 140Pr for PET investigations. In the third experimental chapter, analogously to physical-chemical transitions after the radioactive decay of 140Nd in 140Pr-DOTA, the rapture of the chemical bond between a radiolanthanide and the DOTA ligand, after the thermal neutron capture reaction (Szilard-Chalmers effect) was evaluated for production of the relevant radiolanthanides with high specific activity at TRIGA II Mainz nuclear reactor. The physical-chemical model was developed and first quantitative data are presented. As an example, 166Ho could be produced with a specific activity higher than its limiting value for TRIGA II Mainz, namely about 2 GBq/mg versus 0.9 GBq/mg. While free 166Ho(III) is produced in situ, it is not forming a 166Ho-DOTA complex and therefore can be separated from the inactive 165Ho-DOTA material. The analysis of the experimental data shows that radionuclides with half-life T½ < 64 h can be produced on TRIGA II Mainz nuclear reactor, with specific activity higher than any available at irradiation of simple targets e.g. oxides.

Spin-crossover in metallomesogens of iron(II)

Covalent grafting mesogenic groups to the coordination cores of the parent mononuclear low-spin and spin-crossover compounds afforded metallomesogenic complexes of iron(II). In comparison with the parent complexes the spin-crossover properties of the alkylated derivatives are substantially modified. The type of the modification was found to be dependent on the properties of the parent system and the nature of the used anion, however, the general tendency is the destabilization of the low-spin state at the favor of spin-crossover or high-spin behavior below 400 K. The structural insight revealed the micro-segregated layered organization. The effect of the alkylation of the parent compounds consists first of all in the change of the lattice to a two-dimensional lamellar one retaining significant intermolecular contacts only within the ionic bilayers. The comprehensive analysis of the structural and thermodynamic data in the homologous series pointed at the mechanism of the interplay between the structural modification on melting and the induced anomalous change of the magnetic properties. A family of one-dimensional spin-crossover polymers was synthesized and characterized using a series of spectroscopic methods, X-ray powder diffraction, magnetic susceptibility measurements and differential scanning calorimetry. The copper analogue of was also synthesized and its crystal structure solved. In comparison with the mononuclear systems, the polymeric mesogens of iron(II) are less sensitive to the glass transition, which was attributed to the moderate concomitant variation of the structure. Nevertheless, the observed increase of the magnetic hysteresis with lengthening of the alkyl substituents was ascribed to the interplay of the structural reorganization of the coordination core due to spin-crossover with the structural delay in the spatial reorganization of the mesogenic substituents. The classification of mononuclear and polymeric metallomesogens according to the interactions between the structural- and the spin-transition and analysis of the data on the reported spin-crossover metallomesogens led to the separation of three types, namely: Type i: systems with coupling between the electronic structure of the iron(II) ions and the mesomorphic behavior of the substance; Type ii: systems where both transitions coexist in the same temperature region but are not coupled due to competition with the dehydration or due to negligible structural transformation; Type iii: systems where both transitions occur in different temperature regions and therefore are uncoupled. Fine-tuning, in particular regarding the temperature at which the spin-transition occurs with hysteresis properties responsible for the memory effect, are still a major challenge towards practical implementation of spin-crossover materials. A possible answer to the problem could be materials in which the spin-crossover transition is coupled with another transition easily controllable by external stimuli. In the present thesis we have shown the viability of the approach realized in the mesogenic systems with coupled phase- and spin-transitions.

Design, synthesis and application of ultrastable rylene dyes for fluorescent labeling of biomolecules

Studies of organic fluorescent dyes are experiencing a renaissance related to the increasing demands posed by new microscopy techniques for high resolution and high sensitivity. While in the last decade single molecule equipment and methodology has significantly advanced and in some cases reached theoretical limits (e.g. detectors approaching unity quantum yields) unstable emission from chromophores and photobleaching become more and more the bottleneck of the advancement and spreading of single-molecule fluorescence studies. The main goal of this work was the synthesis of fluorophores that are water-soluble, highly fluorescent in an aqueous environment, have a reactive group for attachment to a biomolecule and posses exceptional photostability. An approach towards highly fluorescent, water-soluble and monofunctional perylene-3,4,9,10-tetracarboxdiimide and terrylene-3,4:11,12-tetra carboxidiimide chromophores was presented. A new synthetic strategy for the desymmetrization of perylenetetracarboximides was elaborated; water-solubility was accomplished by introducing sulfonyl substituents in the phenoxy ring. Two strategies have been followed relying on either non-specific or site specific labeling. For this purpose a series of new water-soluble monofunctional perylene and terrylene dyes, bearing amine or carboxy group were prepared. The reactivity and photophysical properties of these new chromophores were studied in aqueous medium. The most suitable chromophores were further derivatized with amine or thiol reactive groups, suitable for chemical modification of proteins. The performance of the new fluorescent probes was assessed by single molecule enzyme tracking, in this case phospholipase acting on phospholipid supported layers. Phospholipase-1 (PLA-1) was labeled with N-hydroxysuccinimide ester functionalized perylene and terrylene derivatives. The purification of the conjugates was accomplished by novel convenient procedure for the removal of unreacted dye from labeled enzymes, which involves capturing excess dye with a solid support. This novel strategy for purification of bioconjugates allows convenient and fast separation of labeled proteins without the need for performing time consuming chromatographic or electrophoretic purification steps. The outstanding photostability of the dyes and, associated therewith, the extended survival times under strong illumination conditions allow a complete characterization of enzyme action on its natural substrates and even connecting enzyme mobility to catalytic activity. For site-specific attachment of the rylene dyes to proteins the chromophores were functionalized with thioesters or nitrilotriacetic acid groups. This allowed attachment of the emitters to the N-terminus of proteins by native chemical ligation or complexation with His-tagged polypeptides at the N- or C-termini, respectively. The synthesis of a water-soluble perylenebis (dicarboximide) functionalized with a thioester group was presented. This chromophore exhibits an exceptional photostability and a functional unit for site-specific labeling of proteins. The suitability of the fluorophore as a covalent label was demonstrated via native chemical ligation with protein containing N-terminal cystein residue. We exploited also oligohisitidine sequences as recognition elements for site-selective labeling. The synthesis of a new water-soluble perylene chromophore, containing a nitrilotriacetic acid functional group was demonstrated, using solution-phase and solid-phase approaches. This chromophore combines the exceptional photophysical properties of the rylene dyes and a recognition unit for site-specific labeling of proteins. An important feature of the label is the unchanged emission of the dye upon complexation with nickel ions.

Mixtures of colloidal rods and spheres in bulk and in confinement

When non-adsorbing polymers are added to an isotropic suspension of rod-like colloids, the colloids effectively attract each other via depletion forces. Monte Carlo simulations were performed to study the phase diagram of such rod-polymer mixtures. The colloidal rods were modelled as hard spherocylinders; the polymers were described as spheres of the same diameter as the rods. The polymers may overlap with no energy cost, while overlap of polymers and rods is forbidden. In this thesis the emphasis was on the depletion effects caused by the addition of spheres on the isotropic phase of rod-like particles. Although most of the present experimental studies consider systems close to or beyond the isotropic-nematic transition, the isotropic phase with depletion interactions turns out to be a not less interesting topic. First, the percolation problem was studied in canonical simulations of a system of hard rods and soft spheres, where the amount of depletant was kept low to prevent phase separation of the mixture. The lowering of the percolation threshold seen in experiment is confirmed to be due to the depletion interactions. The local changes in the structure of the fluid of rods, which were measured in the simulations, indicated that the depletion forces enhance local alignment and aggregation of the rods. Then, the phase diagram of isotropic-isotropic demixing of short spherocylinders was calculated using grand canonical ensemble simulations with successive umbrella sampling. Finite size scaling analysis allowed to estimate the location of the critical point. Also, estimates for the interfacial tension between the coexisting isotropic phases and analyses of its power-law behaviour on approach of the critical point are presented. The obtained phase diagram was compared to the predictions of the free volume theory. After an analysis of the bulk, the phase behaviour in confinement was studied. The critical point of gas-liquid demixing is shifted to higher concentrations of rods and smaller concentrations of spheres due to the formation of an orientationally ordered surface film. If the separation between the walls becomes very small, the critical point is shifted back to smaller concentrations of rods because the surface film breaks up. A method to calculate the contact angle of the liquid-gas interface with the wall is introduced and the wetting behaviour on the approach to the critical point is analysed.