Sweet's syndrome in a patient with haemophilia, HIV and hepatitis C infection

Sweet's syndrome is a rare skin condition associated with both drug treatment and a number of different disease processes including haematological malignancies, inflammatory conditions and HIV infection. In this case report, we present a patient with HIV, haemophilia and hepatitis C who presented to our team with significant thrombocytopaenia and Sweet's syndrome. We discuss the difficulties with diagnosis and management in the context of multiple co-morbidities and suggest that both hepatitis C and HIV may have been aetiologically involved by suppressing platelet production and also causing bone marrow-driven neutrophilic disease.

Abstract 106: A Novel Small Molecule Protects Against Myocardial Ischemia and Doxorubicin-Induced Cardiomyopathy Through Heat Shock Response and Proteostasis Regulation In Vivo

Background: A potentially new non-cell-based therapy is the systemic delivery of small molecules to revive or protect injured myocardium. By screening a drug library, we identified a novel small molecule, sk421, and tested its effectiveness in two myocardial injury models in vivo: a myocardial infarction model and doxorubicin (DOX)-induced cardiomyopathy model.

Results: Sk421 significantly increased cellular viability of DOX-injured cardiomyocytes by preventing apoptosis in vitro, demonstrated by assays for MTT (p=0.042), annexin-V, and active caspase-3 (p=0.004). Sk421 increased the concentrations of the GATA4 and the heat shock proteins (HSPs) in cardiomyocytes (by 1.5-fold), and fibroblasts (by 1.2-fold), but was unable to rescue DOX-injured fibroblast cells depleted of HSPs. Sk421 maintained the total proteosome by a 3.5-fold inhibition of ubiquitinized GATA4 degradation, as shown by immunoprecipitation assays. Oral administration of sk421(4mg/kg) rescued DOX-injured mice by significantly preserving cardiac function, weight gain, cardiomyocyte lesion size and abundance, and by reducing overall mortality (20% in treated groups) compared to control DOX-injured mice (80% in untreated groups, p<0.03). The levels of GATA4 and HSPs were increased in the sk421-rescued mice. In the MI model, (n=5/group), sk421 reduced myocardial infarct size, and protected heart function evaluated by ejection fraction 45.8 ± 2.4 vs. 34.8 ± 3.3, p=0.005 (day7), and 44.3 ± 2.8 vs. 34.4 ± 4.1, p=0.011 (day28). Sk421 treatment of MI rats resulted in a higher fraction of viable tissue (within the LV (70.20 ± 0.5024, n=3) as compared to only MI group (56.38 ± 3.879%, n=3) and the infiltration of CD68+ cells was found to be more in the infarct region of LV of MI group rats as compared to MI+CEL. Quantitative analysis showed a significantly higher proportion of TUNEL positive cells and mRNA levels of IL-1β, IL-6, TNF-α and MMP2 in the myocardium of MI rats compared to MI+SK421 rats.

Conclusion: This study demonstrates the broad therapeutic benefit of sk421 in animal model of myocardial injury by mechanism of inducing the heat shock response and preserving GATA levels. The ease of oral delivery makes sk421 a potentially clinically useful adjunct for myocardial preservation.

A randomised study of peri-prosthetic bone density after cemented versus trabecular fixation of a polyethylene acetabular component

The ideal acetabular component is characterised by reliable, long-term fixation with physiological loading of bone and a low rate of wear. Trabecular metal is a porous construct of tantalum which promotes bony ingrowth, has a modulus of elasticity similar to that of cancellous bone, and should be an excellent material for fixation. Between 2004 and 2006, 55 patients were randomised to receive either a cemented polyethylene or a monobloc trabecular metal acetabular component with a polyethylene articular surface. We measured the peri-prosthetic bone density around the acetabular components for up to two years using dual-energy x-ray absorptiometry. We found evidence that the cemented acetabular component loaded the acetabular bone centromedially whereas the trabecular metal monobloc loaded the lateral rim and behaved like a hemispherical rigid metal component with regard to loading of the acetabular bone. We suspect that this was due to the peripheral titanium rim used for the mechanism of insertion.

Creation of a gilded trap by the high economic value of the Maine lobster fishery

Unsustainable fishing simplifies food chains and, as with aquaculture, can result in reliance on a few economically valuable species. This lack of diversity may increase risks of ecological and economic disruptions. Centuries of intense fishing have extirpated most apex predators in the Gulf of Maine (United States and Canada), effectively creating an American lobster (Homarus americanus) monoculture. Over the past 20 years, the economic diversity of marine resources harvested in Maine has declined by almost 70%. Today, over 80% of the value of Maine's fish and seafood landings is from highly abundant lobsters. Inflation-corrected income from lobsters in Maine has steadily increased by nearly 400% since 1985. Fisheries managers, policy makers, and fishers view this as a success. However, such lucrative monocultures increase the social and ecological consequences of future declines in lobsters. In southern New England, disease and stresses related to increases in ocean temperature resulted in more than a 70% decline in lobster abundance, prompting managers to propose closing that fishery. A similar collapse in Maine could fundamentally disrupt the social and economic foundation of its coast. We suggest the current success of Maine's lobster fishery is a gilded trap. Gilded traps are a type of social trap in which collective actions resulting from economically attractive opportunities outweigh concerns over associated social and ecological risks or consequences. Large financial gain creates a strong reinforcing feedback that deepens the trap. Avoiding or escaping gilded traps requires managing for increased biological and economic diversity. This is difficult to do prior to a crisis while financial incentives for maintaining the status quo are large. The long-term challenge is to shift fisheries management away from single species toward integrated social-ecological approaches that diversify local ecosystems, societies, and economies.

Parametric study of a Hill-type hyperelastic skeletal muscle model

Hill's one-dimensional three-element model has often been used for formulating a three-dimensional skeletal muscle constitutive model, which generally involves several material parameters. However, only few of these parameters have physical meanings and can be experimentally determined. In this paper, a parametric study of a Hill-type hyperelastic skeletal muscle model is performed. First, the Hill-type hyperelastic skeletal muscle model is formulated, containing 13 material parameters. The values or value ranges of these parameters are discussed. The muscle model is then used to predict the behaviour of New Zealand white rabbit hind leg muscle tibialis anterior and a sensitivity study of several parameters is performed. Results show that some parameters in the muscle model can be experimentally determined, some parameters have their own value ranges and the muscle model can predict the experimental data by tuning the parameters within their value ranges. The results from the sensitivity study can help understand how some parameters influence the total muscle stress.

Attenuation of mouse melanoma by A/C magnetic field after delivery of bi-magnetic nanoparticles by neural progenitor cells

Localized magnetic hyperthermia as a treatment modality for cancer has generated renewed interest, particularly if it can be targeted to the tumor site. We examined whether tumor-tropic neural progenitor cells (NPCs) could be utilized as cell delivery vehicles for achieving preferential accumulation of core/shell iron/iron oxide magnetic nanoparticles (MNPs) within a mouse model of melanoma. We developed aminosiloxane-porphyrin functionalized MNPs, evaluated cell viability and loading efficiency, and transplanted neural progenitor cells loaded with this cargo into mice with melanoma. NPCs were efficiently loaded with core/shell Fe/Fe(3)O(4) MNPs with minimal cytotoxicity; the MNPs accumulated as aggregates in the cytosol. The NPCs loaded with MNPs could travel to subcutaneous melanomas, and after A/C (alternating current) magnetic field (AMF) exposure, the targeted delivery of MNPs by the cells resulted in a measurable regression of the tumors. The tumor attenuation was significant (p < 0.05) a short time (24 h) after the last of three AMF exposures.

A/C magnetic hyperthermia of melanoma mediated by iron(0)/iron oxide core/shell magnetic nanoparticles: a mouse study

BACKGROUND

There is renewed interest in magnetic hyperthermia as a treatment modality for cancer, especially when it is combined with other more traditional therapeutic approaches, such as the co-delivery of anticancer drugs or photodynamic therapy.

METHODS

The influence of bimagnetic nanoparticles (MNPs) combined with short external alternating magnetic field (AMF) exposure on the growth of subcutaneous mouse melanomas (B16-F10) was evaluated. Bimagnetic Fe/Fe3O4 core/shell nanoparticles were designed for cancer targeting after intratumoral or intravenous administration. Their inorganic center was protected against rapid biocorrosion by organic dopamine-oligoethylene glycol ligands. TCPP (4-tetracarboxyphenyl porphyrin) units were attached to the dopamine-oligoethylene glycol ligands.

RESULTS

The magnetic hyperthermia results obtained after intratumoral injection indicated that micromolar concentrations of iron given within the modified core-shell Fe/Fe3O4 nanoparticles caused a significant anti-tumor effect on murine B16-F10 melanoma with three short 10-minute AMF exposures. We also observed a decrease in tumor size after intravenous administration of the MNPs followed by three consecutive days of AMF exposure 24 hrs after the MNPs injection.

CONCLUSIONS

These results indicate that intratumoral administration of surface modified MNPs can attenuate mouse melanoma after AMF exposure. Moreover, we have found that after intravenous administration of micromolar concentrations, these MNPs are capable of causing an anti-tumor effect in a mouse melanoma model after only a short AMF exposure time. This is a clear improvement to state of the art.

An efficient approach to converting three-dimensional image data into highly accurate computational models

Image-based meshing is opening up exciting new possibilities for the application of computational continuum mechanics methods (finite-element and computational fluid dynamics) to a wide range of biomechanical and biomedical problems that were previously intractable owing to the difficulty in obtaining suitably realistic models. Innovative surface and volume mesh generation techniques have recently been developed, which convert three-dimensional imaging data, as obtained from magnetic resonance imaging, computed tomography, micro-CT and ultrasound, for example, directly into meshes suitable for use in physics-based simulations. These techniques have several key advantages, including the ability to robustly generate meshes for topologies of arbitrary complexity (such as bioscaffolds or composite micro-architectures) and with any number of constituent materials (multi-part modelling), providing meshes in which the geometric accuracy of mesh domains is only dependent on the image accuracy (image-based accuracy) and the ability for certain problems to model material inhomogeneity by assigning the properties based on image signal strength. Commonly used mesh generation techniques will be compared with the proposed enhanced volumetric marching cubes (EVoMaCs) approach and some issues specific to simulations based on three-dimensional image data will be discussed. A number of case studies will be presented to illustrate how these techniques can be used effectively across a wide range of problems from characterization of micro-scaffolds through to head impact modelling.

Detection of cathepsin S cysteine protease in human brain tumour microdialysates in vivo

Microdialysis enables the chemistry of extracellular fluid in body tissues to be measured. Extracellular proteases such as the cysteine protease, cathepsin S (CatS), are thought to facilitate astrocytoma invasion. Microdialysates obtained from human brain tumours in vivo were subjected to cathepsin S activity and ELISA assays. Cathepsin S ELISA expression was detected in five out of 10 tumour microdialysates, while activity was detected in five out of 11 tumour microdialysates. Cathepsin S expression was also detected in microdialysate from the normal brain control although no activity was found in the same sample. While some refinements to the technique are necessary, the authors demonstrate the feasibility and safety of microdialysis in human astrocytomas in vivo. Characterisation of the extracellular environment of brain tumours in vivo using microdialysis may be a useful tool to identify the protease profile of brain tumours.

The emerging role of serine proteases in apoptosis

Unregulated apoptosis can be due to a disruption in the balance and control of both intra- and inter-cellular proteolytic activities leading to various disease states. Many proteases involved in apoptotic processes are yet to be identified; however, several are already well characterized. Caspases traditionally held the predominant role as prime mediators of execution. However, latterly, evidence has accumulated that non-caspases, including calpains, cathepsins, granzymes and the proteasome have roles in mediating and promoting cell death. Increasingly, research is implicating serine proteases within apoptotic processing, particularly in the generation of nuclear events such as condensation, fragmentation and DNA degradation observed in late-stage apoptosis. Serine proteases therefore are emerging as providing additional or alternative therapeutic targets.

Poikiloderma, tendon contracture and pulmonary fibrosis: a new autosomal dominant syndrome?

Members of two generations of a South African family have a unique syndrome comprising poikiloderma, tendon contractures and progressive pulmonary fibrosis. The condition is clinically important as the skin changes, which involve the face, have considerable cosmetic impact, while lung involvement is potentially lethal in adulthood. Skin manifestations which facilitate diagnosis include facial telangiectasia, mottled hypo- and hyperpigmentation, papules and epidermal atrophy. The scalp, facial and body hair are fine and scanty. The tendon contractures lead to progressive digital flexion deformities and abnormalities of the ankles and feet, with disturbance of gait. Pulmonary involvement manifests as progressive dyspnoea. Pedigree data are compatible with an autosomal dominant mode of transmission. Poikiloderma of Weary is characterized by linear sclerotic and fibrous bands and not tendon contractures and is not associated with potentially lethal pulmonary fibrosis. Rather than name this disorder a variant of Weary syndrome, it might be prudent to use as an umbrella title one composed by Weary himself: 'hereditary sclerosing poikiloderma' (HSP), under which variants such as HSP Weary type, HSP with cardiac involvement (aortic stenosis described as inconsistently associated with Weary syndrome) and HSP with tendon/pulmonary involvement (current family) may be classified. The manifestations in this family differ from other poikilodermata and, to the best of our knowledge, have not been previously documented.

Structured treatment interruptions following immediate initiation of HAART in eight patients with acute HIV-1 seroconversion

BACKGROUND

The immunological and clinical benefits of structured treatment interruptions (STIs) during primary HIV-1 infection remain largely unclear.

PATIENTS AND METHODS

Eight patients identified during primary HIV-1 infection were immediately treated with HAART and underwent subsequent STIs after reaching complete viral suppression of HIV-RNA in peripheral plasma. HAART was re-initiated if either HIV-1 RNA >5000 copies/ml, CD4-cells <200 cells/microl or symptomatic HIV-1 disease was observed.

RESULTS

After treatment discontinuation, four of eight patients were able to persistently control HIV-1 viremia below 5000 copies/ml until the last time point of follow-up (median 3 years). CD4-cell counts were within the interquartile range of untreated individuals compared to historical reference data from the MACS cohort. In the remaining study subjects persistent virological control was not reached despite repeated STIs. Moreover, compared to the MACS cohort repetitive virological failures during STIs appeared to induce an accelerated decline of CD4-cells.

CONCLUSION

Spontaneous HIV-1 control after treated primary HIV-1 infection was possible in four out of eight individuals, however, if STIs after treated primary infection ameliorate the overall HIV-1 disease progression remains unknown. In the absence of viral control, repetitive viral exposure during STIs might be associated with accelerated decline of CD4-cell counts.