[Spinal cord toxoplasmosis in HIV infection]

We report the case of an atypical localization of a spinal cord "toxoplasmic abscess". The 46-year-old patient, HIV-1 positive, was admitted for acute urine retention and gait disorders. MRI revealed a T12-L1 medullary lesion suggesting a tumoral, inflammatory and infectious pathology. The radiological aspect and immunosuppression lead to the initiation of a treatment against Toxoplasma gondii, following the same treatment principles as for cerebral toxoplasmosis. The diagnosis can only be proved by data from autopsy or surgical biopsy, but toxoplasmosis PCR on CSF seems to be an interesting alternative to confirm the diagnosis. According to the literature, PCR is not sensitive enough as a diagnostic tool. Improvement after treatment supported the diagnosis confirmed by PCR.

Chromatin modifications: the driving force of senescence and aging?

An emerging field of investigation in the search for treatment of human disease is the modulation of chromatin modifications. Chromatin modifications impart virtually all processes occurring in the mammalian nucleus, from regulation of transcription to genomic stability and nuclear high order organization. It has been well recognized that, as the mammalian cell ages, its chromatin structure evolves, both at a global level and at specific loci. While these observations are mostly correlative, recent technical developments allowing loss-of-function experiments and genome-wide approaches have permitted the identification of a causal relationship between specific changes in chromatin structure and the aging phenotype. Here we review the evidence pointing to the modulation of chromatin structure as a potential driving force of cellular aging in mammals.

The effect of climate change on the occurrence and prevalence of livestock diseases in Great Britain: a review

There is strong evidence to suggest that climate change has, and will continue to affect the occurrence, distribution and prevalence of livestock diseases in Great Britain (GB). This paper reviews how climate change could affect livestock diseases in GB. Factors influenced by climate change and that could affect livestock diseases include the molecular biology of the pathogen itself; vectors (if any); farming practice and land use; zoological and environmental factors; and the establishment of new microenvironments and microclimates. The interaction of these factors is an important consideration in forecasting how livestock diseases may be affected. Risk assessments should focus on looking for combinations of factors that may be directly affected by climate change, or that may be indirectly affected through changes in human activity, such as land use (e.g. deforestation), transport and movement of animals, intensity of livestock farming and habitat change. A risk assessment framework is proposed, based on modules that accommodate these factors. This framework could be used to screen for the emergence of unexpected disease events.

Suppression pattern of neutral pions at high transverse momentum in Au + Au collisions at sqrt[sNN]=200 GeV and constraints on medium transport coefficients

For Au + Au collisions at 200 GeV, we measure neutral pion production with good statistics for transverse momentum, pT, up to 20 GeV/c. A fivefold suppression is found, which is essentially constant for 5 < pT < 20 GeV/c. Experimental uncertainties are small enough to constrain any model-dependent parametrization for the transport coefficient of the medium, e.g., q in the parton quenching model. The spectral shape is similar for all collision classes, and the suppression does not saturate in Au + Au collisions.

Onset of pi(0) suppression studied in Cu+Cu collisions at sqrt S NN=22.4, 62.4, and 200 GeV

Neutral pion transverse momentum (p(T)) spectra at midrapidity (|y| less than or approximately 0.35) were measured in Cu+Cu collisions at sqrt[s(NN)]=22.4, 62.4, and 200 GeV. Relative to pi_(0) yields in p+p collisions scaled by the number of inelastic nucleon-nucleon collisions (N(coll) the pi_(0) yields for p(T) more than or approximately 2 GeV/c in central Cu+Cu collisions are suppressed at 62.4 and 200 GeV whereas an enhancement is observed at 22.4 GeV. A comparison with a jet-quenching model suggests that final state parton energy loss dominates in central Cu+Cu collisions at 62.4 and 200 GeV, while the enhancement at 22.4 GeV is consistent with nuclear modifications in the initial state alone.

J/psi production in sqrt s_NN=200 GeV Cu+Cu collisions

Yields for J/psi production in Cu+Cu collisions at sqrt s_NN=200 GeV have been measured over the rapidity range |y|<2.2 and compared with results in p+p and Au+Au collisions at the same energy. The Cu+Cu data offer greatly improved precision over existing Au+Au data for J/psi production in collisions with small to intermediate numbers of participants, in the range where the quark-gluon plasma transition threshold is predicted to lie. Cold nuclear matter estimates based on ad hoc fits to d+Au data describe the Cu+Cu data up to N_part approximately 50, corresponding to a Bjorken energy density of at least 1.5 GeV/fm(3).

Particle-species dependent modification of jet-induced correlations in Au+Au collisions at sqrt[s_{NN}]=200 GeV

Measurements in Au+Au collisions at sqrt[s_{NN}]=200 GeV of jet correlations for a trigger hadron at intermediate transverse momentum (p_{T,trig}) with associated mesons or baryons at lower p_{T,assoc} indicate strong modification of the away-side jet. The ratio of jet-associated baryons to mesons increases with centrality and p_{T,assoc}. For the most central collisions, the ratio is similar to that for inclusive measurements. This trend is incompatible with in-vacuum fragmentation but could be due to jetlike contributions from correlated soft partons, which recombine upon hadronization.

[Aspergillosis for the pulmonologist]

Aspergillus is involved in various lung illnesses related to type of exposition and immunity host response, local (tracheobronchial) and global. Allergic bronchopulmonary aspergillosis is due to a hypersensitivity response, diagnosis must be considered in presence of severe asthma with radiologic opacities, blood eosinophilia and elevated total serum IgE levels. Bronchial colonization is often accidentally discovered, but needs a monitoring. Pulmonary aspergilloma, often asymptomatic, grows in a preexisting cavity. Aspergillus bronchitis is a prolonged superficious endobronchial infection. Pseudomembranous necrotizing tracheobronchitis is a microinvasive bronchial infection, which prognosis is very bad. Acute invasive pulmonary aspergillosis affects quite always immunocompromised patients, but cases are not exceptional in patients with prior lung disease. Chronic necrotizing pulmonary aspergillosis may be divided in chronic cavitary and chronic fibrosing pulmonary aspergillosis, and subacute invasive aspergillosis according to the course of the disease, radiological outcome first. Management of diseases caused by Aspergillus is evolving with new diagnostic tools (PCR, Aspergillus antigenemia) and with new generation antifungal drugs.

Source breakup dynamics in Au + Au collisions at sqrt[s(NN)]=200 GeV via three-dimensional two-pion source imaging

A three-dimensional correlation function obtained from midrapidity, low p(T), pion pairs in central Au+Au collisions at sqrt[s(NN)]=200 GeV is studied. The extracted model-independent source function indicates a long range tail in the directions of the pion pair transverse momentum (out) and the beam (long). A proper breakup time tau(0) ~ 9 fm/c and a mean proper emission duration Delta tau ~ 2 fm/c, leading to sizable emission time differences ({|Delta t(LCM)|} approximately 12 fm/c), are required to allow models to be successfully matched to these tails. The model comparisons also suggest an outside-in "burning" of the emission source reminiscent of many hydrodynamical models.

Sin3B: an essential regulator of chromatin modifications at E2F target promoters during cell cycle withdrawal

Efficient and accurate cell cycle exit is intimately linked to cellular differentiation, and by inference, to the prevention of tumorigenesis. Perhaps the most important axis of control for this process involves the interactions of the E2F family of DNA binding proteins with the retinoblastoma (Rb) and Rb-related "pocket protein" (p107 and p130) family of tumor suppressors. Not surprisingly, alterations in this pathway are present in a large number of human malignancies. The molecular basis for the controls exercised by the Rb family of proteins has been widely investigated, but is still not completely understood. Elegant in vitro studies had previously suggested the participation of histone deacetylase (HDAC)-associated Sin3B in E2F-mediated repression. Using genetically modified mice, we have recently uncovered a role for the Sin3B protein as a specific and essential actor in promoting cell cycle exit via the E2F-Rb pathway. We demonstrated its absolute requirement not only for cell cycle exit in vitro and in vivo, but also for biological processes linked to cellular differentiation. These observations strongly suggest that Sin3B plays an essential role in coordinating the chromatin modifying activities required for the transient repression of pro-proliferation genes in quiescence, as well as stable silencing of these genes upon terminal differentiation.

The F-box protein Fbl10 is a novel transcriptional repressor of c-Jun

c-Jun is a component of the heterodimeric transcription factor AP-1 that is rapidly activated in response to ultraviolet light (UV). In unstressed cells, c-Jun activity is negatively regulated by transcriptional repressor complexes. Here we show that the F-box protein Fbl10/JHDM1B interacts with c-Jun and represses c-Jun-mediated transcription. Chromatin-immunoprecipitation assays demonstrate that Fbl10 is present at the c-jun promoter, and that c-Jun is required for the recruitment of Fbl10. Fbl10 binds to the unmethylated CpG sequences in the c-jun promoter through the CxxC zinc finger and tethers transcriptional repressor complexes. Suppression of Fbl10 expression by RNA interference (RNAi) induces transcription of c-jun and other c-Jun-target genes, and causes an aberrant cell-cycle progression and increased UV-induced cell death. Furthermore, Fbl10 protein and messenger RNA are downregulated in response to UV in an inverse correlation with c-Jun. Taken together, our results demonstrate that Fbl10 is a key regulator of c-Jun function.

Elliptic flow for phi mesons and (anti)deuterons in Au+Au collisions at square root of sNN=200 GeV

Differential elliptic flow (v(2)) for phi mesons and (anti)deuterons (d)d is measured for Au+Au collisions at square root of sNN=200 GeV. The v(2) for phi mesons follows the trend of lighter pi+/- and K+/- mesons, suggesting that ordinary hadrons interacting with standard hadronic cross sections are not the primary driver for elliptic flow development. The v(2) values for (d)d suggest that elliptic flow is additive for composite particles. This further validation of the universal scaling of v(2) per constituent quark for baryons and mesons suggests that partonic collectivity dominates the transverse expansion dynamics.

Altered multiaxial mechanical properties of the porcine anterior lens capsule cultured in high glucose

Hyperglycemia can alter the mechanical properties of tissues through the formation of advanced glycation endproducts in matrix proteins that have long half-lives. We used a custom experimental system and subdomain finite element method to quantify alterations in the regional multiaxial mechanical properties of porcine lens capsules that were cultured for 8 or 14 weeks in high glucose versus control media. Findings revealed that high glucose significantly stiffened the capsules in both the circumferential and the meridional directions, but it did not affect the known regional variations in anisotropy. Such information could be important in the design of both improved clinical procedures and intraocular implants for diabetic patients.

Regional multiaxial mechanical properties of the porcine anterior lens capsule

The lens capsule of the eye plays fundamental biomechanical roles in both normal physiological processes and clinical interventions. There has been modest attention given to the mechanical properties of this important membrane, however, and prior studies have focused on 1-D analyses of the data. We present results that suggest that the porcine anterior lens capsule has a complex, regionally dependent, nonlinear, anisotropic behavior. Specifically, using a subdomain inverse finite element method to analyze data collected via a new biplane video-based test system, we found that the lens capsule is nearly isotropic (in-plane) near the pole but progressively stiffer in the circumferential compared to the meridional direction as one approaches the equator. Because the porcine capsule is a good model of the young human capsule, there is strong motivation to determine if similar regional variations exist in the human lens capsule for knowledge of such complexities may allow us to improve the design of surgical procedures and implants.

Basic life support on small boats at sea

The present study examined the ability of the crew of small fast rescue boats to perform basic life support (BLS) at sea. Tests were undertaken aboard a 67m emergency response and rescue vessel (ERRV), a 9.1m (30ft) and 11.6m (38ft) fast rescue craft ("daughter craft" (DC)). It was hypothesised that the ability to perform BLS on a DC would be significantly impaired when compared with that seen on the ERRV. Nine DC crew volunteered for the study. These tests were undertaken in sea states ranging from 0.5 to 6 (13cm to 4m wave height). Wind speeds ranged between 0 and 35knots. The deterioration observed in the performance of BLS on board the DC compared to that seen on the ERRV was significant (P<0.05) and was due, in part, to a tendency to over-inflate during rescue breathing, and under-compress during BLS when on the DC. Chest compression (CC) was impaired significantly above a sea state 3 (wave height 61-92cm). It is concluded that the performance of BLS on small boats, in particular rescue breathing, is significantly adversely affected by two major factors, motion-induced interruption and early fatigue. As a consequence, the likelihood of conducting fully effective continuous BLS on a small boat in a seaway for any length of time, with a good chance of a successful outcome, is considered to be poor. However, this should not deter rescuers from attempting to make such efforts where practicable.

System size and energy dependence of jet-induced hadron pair correlation shapes in Cu+Cu and Au+Au collisions at square root sNN=200 and 62.4 GeV

We present azimuthal angle correlations of intermediate transverse momentum (1-4 GeV/c) hadrons from dijets in Cu+Cu and Au+Au collisions at square root sNN=62.4 and 200 GeV. The away-side dijet induced azimuthal correlation is broadened, non-Gaussian, and peaked away from Delta phi=pi in central and semicentral collisions in all the systems. The broadening and peak location are found to depend upon the number of participants in the collision, but not on the collision energy or beam nuclei. These results are consistent with sound or shock wave models, but pose challenges to Cherenkov gluon radiation models.

J/psi production versus transverse momentum and rapidity in p+p collisions at square root s=200 GeV

J/psi production in p+p collisions at square root s=200 GeV has been measured by the PHENIX experiment at the BNL Relativistic Heavy Ion Collider over a rapidity range of -2.2<y<2.2 and a transverse momentum range of 0<pT<9 GeV/c. The size of the present data set allows a detailed measurement of both the pT and the rapidity distributions and is sufficient to constrain production models. The total cross section times the branching ratio is Bll sigma pp J/psi=178+/-3stat+/-53sys+/-18norm nb.

J/psi production versus centrality, transverse momentum, and rapidity in Au+Au collisions at square root sNN=200 GeV

The PHENIX experiment at the BNL Relativistic Heavy Ion Collider (RHIC) has measured J/psi production for rapidities -2.2<y<2.2 in Au+Au collisions at square root sNN=200 GeV. The J/psi invariant yield and nuclear modification factor RAA as a function of centrality, transverse momentum, and rapidity are reported. A suppression of J/psi relative to binary collision scaling of proton-proton reaction yields is observed. Models which describe the lower energy J/psi data at the CERN Super Proton Synchrotron invoking only J/psi destruction based on the local medium density predict a significantly larger suppression at RHIC and more suppression at midrapidity than at forward rapidity. Both trends are contradicted by our data.

Regional mechanical properties and stress analysis of the human anterior lens capsule

The lens capsule of the eye functions, in part, as a deformable support through which the ciliary body applies tractions that can alter lens curvature and corresponding refractive power during the process of accommodation. Although it has long been recognized that characterization of the mechanical properties of the lens capsule is fundamental to understanding this physiologic process as well as clinical interventions, prior data have been limited by one-dimensional testing of excised specimens despite the existence of multiaxial loading in vivo. In this paper, we employ a novel experimental approach to study in situ the regional, multiaxial mechanical behavior of both normal and diabetic human anterior lens capsules. Furthermore, we use these data to calculate material parameters in a nonlinear stress-strain relation via a custom sub-domain inverse finite element method (FEM). These parameters are then used to predict capsular stresses in response to imposed loads using a forward FEM model. Our results for both normal and diabetic human eyes show that the anterior lens capsule exhibits a nonlinear pseudoelastic behavior over finite strains that is typical of soft tissues, and that strains are principal relative to meridional and circumferential directions. Experimental data and parameter estimation suggest further that the capsule is regionally anisotropic, with the circumferential direction becoming increasingly stiffer than the meridional direction towards the equator. Although both normal and diabetic lens capsules exhibited these general characteristic behaviors, diabetic capsules were significantly stiffer at each distension. Finally, the forward FEM model predicted a nearly uniform, equibiaxial stress field during normalcy that will be perturbed by cataract surgery. Such mechanical perturbations may be an underlying modulator of the sustained errant epithelial cell behavior that is observed well after cataract surgery and may ultimately contribute to opacification of the posterior lens capsule.

Differential expression of syndecans and glypicans in chronically inflamed synovium

BACKGROUND

Membrane-bound heparan sulphate proteoglycans (HSPGs) act as co-receptors and presenters of cytokines and are involved in cell-matrix and cell-cell adhesion.

AIM

To investigate which HSPGs are expressed in knee joint synovia from patients with different forms of arthritis and normal individuals.

METHODS

Synovial samples were obtained from patients with early rheumatoid arthritis (n = 8), longstanding rheumatoid arthritis (n = 13), psoriatic arthritis (n = 7), osteoarthritis (n = 6) and normal joints (n = 12). Expression of syndecan-1, -2, -3 and -4 and glypican-1, -3 and -4 was analysed by immunohistochemistry and dual label immunofluorescence.

RESULTS

The expression of HSPGs in chronically inflamed synovium exhibited a differential distribution. Syndecan-1 was present in the mononuclear infiltrates of synovia from patients with rheumatoid and psoriatic arthritis where it was expressed by plasma cells. Syndecan-2 was present mainly in blood vessels where it occurred on endothelial cells, pericytes and smooth muscle cells. Syndecan-3 stained intensely in endothelial cells but also occurred in sublining macrophages and the lining layer. Glypican-4 occurred in the lining layer and blood vessels. Increased expression of these HSPGs was apparent in rheumatoid and psoriatic compared to osteoarthritic and normal synovia. Little or no staining for syndecan-4, glypican-1 and glypican-3 was seen in all samples.

DISCUSSION

Selected HSPGs, such as syndecan-1, -2 and -3 and glypican-4, could play a part in the pathophysiology of arthritis, such as the migration and retention of leukocytes and angiogenesis in the chronically inflamed synovium.

Finite element model of stresses in the anterior lens capsule of the eye

Continuum biomechanics continues to aid in the design of clinical procedures and biomedical devices. Such design requires detailed information on the biomechanical properties of the tissues of interest as well as appropriate methods of analysis. In this paper, we use a fully nonlinear, virtual work based finite element method to study the normal stress field in the anterior lens capsule of the porcine eye. The analysis shows that recently measured regional variations in material symmetry may combine with regional variations in membrane thickness to yield a nearly uniform and equibiaxial stress field in normalcy. These findings are discussed in terms of potential implications to the underlying mechanobiology and in particular, in terms of perturbations in stress that result from cataract surgery, the most commonly performed surgical procedure in North America.

Decreased EXT expression and intracellular accumulation of heparan sulphate proteoglycan in osteochondromas and peripheral chondrosarcomas

Mutational inactivation of EXT1 or EXT2 is the cause of hereditary multiple osteochondromas. These genes function in heparan sulphate proteoglycan (HSPG) biosynthesis in the Golgi apparatus. Loss of heterozygosity of the EXT1 locus at 8q24 is frequently found in solitary osteochondromas, whereas somatic mutations are rarely found. We investigated the expression of EXT1 and EXT2 (quantitative RT-PCR) and of different HSPGs (immunohistochemistry) in solitary and hereditary osteochondromas and in cases with malignant progression to secondary peripheral chondrosarcoma, in relation to possible mutations and promoter methylation. The mutation status of patients with multiple osteochondromas correlated with decreased EXT1 or EXT2 expression found in their resected tumours. We could not show somatic point mutations or promoter hypermethylation in 17 solitary tumours; however, EXT1 expression was decreased in 15 cases, whereas EXT2 was not. Intracellular accumulation of syndecan-2 and heparan sulphate-bearing isoforms of CD44 (CD44v3) was found in most tumours, which concentrated in the Golgi apparatus as shown by confocal microscopy. This contrasted with the extracellular expression found in normal growth plates. In conclusion, mutational inactivation of either EXT1 or EXT2 leads to loss of mRNA expression of the corresponding gene. We hypothesize that loss of EXT expression disrupts the function of the EXT1/2 complex in HSPG biosynthesis, resulting in the intracellular accumulation of HSPG core proteins that we found in these tumours.

Scaling properties of azimuthal anisotropy in Au+Au and Cu+Cu Collisions at sqrt[s NN]=200 GeV

Differential measurements of elliptic flow (v2) for Au+Au and Cu+Cu collisions at sqrt[sNN]=200 GeV are used to test and validate predictions from perfect fluid hydrodynamics for scaling of v2 with eccentricity, system size, and transverse kinetic energy (KE T). For KE T identical with mT-m up to approximately 1 GeV the scaling is compatible with hydrodynamic expansion of a thermalized fluid. For large values of KE T mesons and baryons scale separately. Quark number scaling reveals a universal scaling of v2 for both mesons and baryons over the full KE T range for Au+Au. For Au+Au and Cu+Cu the scaling is more pronounced in terms of KE T, rather than transverse momentum.