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In this paper, the quantization dimensions of the Borel probability measures supported on the limit sets of the bi-Lipschitz recurrent iterated function systems under the strong open set condition in terms of the spectral radius have been estimated. [ABSTRACT FROM AUTHOR]

Background: Bigliani types of acromion and critical shoulder angle (CSA) have been implicated as indicators of rotator cuff disease. A sharpened inferolateral edge of acromion (termed as Sharpened Lateral Acromion Morphology or SLAM sign) is frequently observed in anteroposterior radiographs of the glenohumeral joint in patients with rotator cuff tears (RCT). We aimed to evaluate the association of the SLAM sign with RCT in comparison to high CSA (≥35°) and Bigliani type 3 (hooked) acromion. Methods: A cohort of 100 consecutive patients undergoing non-arthroplasty surgery for RCT and 106 patients with primary frozen shoulder were matched manually in 1:1 ratio based on age and gender to yield study population with 50 patients in each group. The 2 groups were compared for the presence of the SLAM sign, high CSA, and type 3 acromion on the radiographs. Results: All the 3 parameters were found more prevalent in the RCT group than the frozen shoulder group (SLAM, 46% vs. 0; high CSA, 60% vs. 40%; type 3 acromion, 18% vs. 4%) (P

If local forms of Littlewood's three principles are stated as axioms for an ordered field, then each principle is equivalent to the completeness axiom. [ABSTRACT FROM AUTHOR]

In this paper, we prove the existence of the bivariate fractal interpolation function using the Rakotch contraction theory and iterated function system for a countable data set. We also give the existence of the invariant Borel probability measure supported on the graph of the bivariate fractal interpolation function. In particular, we highlight that our theory encompasses the bivariate fractal interpolation theory in both finite and countably infinite settings available in literature. [ABSTRACT FROM AUTHOR]

T cells are an important component of adaptive immunity and T-cell-derived lymphomas are very complex due to many functional sub-types and functional elasticity of T-cells. As with other tumors, tissues specific factors are crucial in the development of T-cell lymphomas. In addition to neoplastic cells, T-cell lymphomas consist of a tumor micro-environment composed of normal cells and stroma. Numerous studies established the qualitative and quantitative differences between the tumor microenvironment and normal cell surroundings. Interaction between the various component of the tumor microenvironment is crucial since tumor cells can change the microenvironment and vice versa. In normal T-cell development, T-cells must respond to various stimulants deferentially and during these courses of adaptation. T-cells undergo various metabolic alterations. From the stage of quiescence to attention of fully active form T-cells undergoes various stage in terms of metabolic activity. Predominantly quiescent T-cells have ATP-generating metabolism while during the proliferative stage, their metabolism tilted towards the growth-promoting pathways. In addition to this, a functionally different subset of T-cells requires to activate the different metabolic pathways, and consequently, this regulation of the metabolic pathway control activation and function of T-cells. So, it is obvious that dynamic, and well-regulated metabolic pathways are important for the normal functioning of T-cells and their interaction with the microenvironment. There are various cell signaling mechanisms of metabolism are involved in this regulation and more and more studies have suggested the involvement of additional signaling in the development of the overall metabolic phenotype of T cells. These important signaling mediators include cytokines and hormones. The impact and role of these mediators especially the cytokines on the interplay between T-cell metabolism and the interaction of T-cells with their micro-environments in the context of T-cells lymphomas are discussed in this review article. [ABSTRACT FROM AUTHOR]

Objectives: Preoperative chemotherapy plays a key role in management of bone sarcomas. Postoperative evaluation of histological necrosis has been the gold standard method of assessing response to preoperative chemotherapy. This study was done to evaluate the efficacy of static and dynamic magnetic resonance imaging (MRI) for assessing response preoperatively. Materials and Methods: Our study included 14 patients (12 osteosarcomas and 2 malignant fibrous histiocytomas) with mean age of 21.8 years, treated with preoperative chemotherapy followed by surgery. They were evaluated with static and dynamic MRI twice, before starting chemotherapy and again prior to surgery. Change in tumor volume and slope of signal intensity - time curve were calculated and correlated with percentage of histological necrosis using Pearson correlation test. Results: The change in dynamic MRI slope was significant (P = 0.001). Also, ≥60% reduction in slope of the curve proved to be an indicator of good histological response [positive predictive value (PPV) =80%]. Change in tumor volume failed to show significant correlation (P = 0.071). Although it showed high negative predictive value (NPV = 85.7%), PPV was too low (PPV = 57.14%). Conclusions: Dynamic MRI correctly predicts histological necrosis after administration of preoperative chemotherapy to bone sarcomas. Hence, it can be used as a preoperative indicator of response to neoadjuvant chemotherapy. On the other hand, volumetric assessment by static MRI is not an effective predictor of histological necrosis. This study proves the superiority of dynamic contrast-enhanced study over volumetric study by MRI.

In this paper, we study the following boundary value problem involving the weak p-Laplacian where is the Sierpiński gasket in , is its boundary, , , and are appropriate functions. We will show the existence of a nontrivial weak solution to the above problem for a certain range of using the analysis of fibering maps on suitable subsets. [ABSTRACT FROM AUTHOR]

In this paper, we study the following boundary value problem involving the weak -Laplacian. where is the Sierpiński gasket in , is its boundary, , , and are bounded nonnegative functions. We will show the existence of at least two nontrivial weak solutions to the above problem for a certain range of using the analysis of fibering maps on suitable subsets. [ABSTRACT FROM AUTHOR]

In this paper we discuss the continuity of the Hausdorff dimension of the invariant set of generalised graph-directed systems given by contractive infinitesimal similitudes on bounded complete metric spaces. We use the theory of positive linear operators to show that the Hausdorff dimension varies continuously with the functions defining the generalised graph-directed system under suitable assumptions. [ABSTRACT FROM PUBLISHER]

In this paper we obtain theorems which give the Hausdorff dimension of the invariant set for a finite family of contraction mappings which are "infinitesimal similitudes" on a complete, perfect metric space. Our work generalizes the graph-directed construction of Mauldin and Williams (1988) and is related in its general setting to results of Schief (1996), but differs crucially in that the mappings need not be similitudes. We use the theory of positive linear operators and generalizations of the Krein-Rutman theorem to characterize the Hausdorff dimension as the unique value of σ > 0 for which r(Lσ) = 1, where Lσ, σ > 0, is a naturally associated family of positive linear operators and r(Lσ) denotes the spectral radius of Lσ. We also indicate how these results can be generalized to countable families of infinitesimal similitudes. The intent here is foundational: to derive a basic formula in its proper generality and to emphasize the utility of the theory of positive linear operators in this setting. Later work will explore the usefulness of the basic theorem and its functional analytic setting in studying questions about Hausdorff dimension. [ABSTRACT FROM AUTHOR]

Abstract: This study reports the crystal structures of Bcl-xl wild type and three Bcl-xl mutants (Y101A, F105A, and R139A) with amino acid substitutions in the hydrophobic groove of the Bcl-xl BH3 domain. An additional 12 ordered residues were observed in a highly flexible loop between the α1 and α2 helices, and were recognized as an important deamidation site for the regulation of apoptosis. The autophagy-effector protein, Beclin 1, contains a novel BH3 domain (residues 101–125), which binds to the surface cleft of Bcl-xl, as confirmed by nuclear magnetic resonance (NMR) spectroscopy and analytical gel-filtration results. Gossypol, a potent inhibitor of Bcl-xl, had a K d value of 0.9μM. In addition, the structural and biochemical analysis of five Bcl-xl substitution mutants will provide structural insights into the design and development of anti-cancer drugs. [Copyright &y& Elsevier]

Abstract: Here we describe in detail the crystal structures of the Vitamin K2 synthesis protein MenD, from Escherichia coli, in complex with thiamine diphosphate (ThDP) and oxoglutarate, and the effects of cofactor and substrate on its structural stability. This is the first reported structure of MenD in complex with oxoglutarate. The residues Gly472 to Phe488 of the active site region are either disordered, or in an open conformation in the MenD oxoglutarate complex structure, but adopt a closed conformation in the MenD ThDP complex structure. Biospecific-interaction analysis using surface plasmon resonance (SPR) technology reveals an affinity for ThDP and oxoglutarate in the nanomolar range. Biochemical and structural analysis confirmed that MenD is highly dependent on ThDP for its structural stability. Our structural results combined with the biochemical assay reveal novel features of the enzyme that could be utilized in a program of rational structure-based drug design, as well as in helping to enhance our knowledge of the menaquinone synthesis pathway in greater detail. [Copyright &y& Elsevier]

Abstract: MenD (2-succinyl-5-enolpyruvyl-6-hydroxy-3-cyclohexadiene-1-carboxylate) synthase belongs to the superfamily of thiamin diphosphate-dependent decarboxylases, which converts isochorismate and 2-oxoglutarate to SHCHC, pyruvate, and carbon dioxide. Here, we report the first crystal structure of apo-MenD from Escherichia coli determined in tetragonal crystal form. The subunit displays the typical three-domain structure observed for ThDP-dependent enzymes. Analytical gel filtration shows that EcMenD behaves as a dimer as well as a tetramer. Circular dichroism and isothermal calorimetry results confirm EcMenD dependency on ThDP, which concomitantly helps to stabilize with better configuration. [Copyright &y& Elsevier]

SicA is a member of the class II chaperones in type III secretion systems which bind to the pore-forming translocators in the bacterial cytoplasm and prevent them from premature association and degradation. In this study, SicA from Salmonella enterica serovar Typhimurium was overexpressed, purified and crystallized using PEG 8000 as the precipitant. X-ray diffraction data were collected using synchrotron radiation and processed at 3.5 Å resolution. The crystal belonged to the monoclinic space group C2, with unit-cell parameters a = 180.4, b = 94.1, c = 131.8 Å, β = 130.9°. There may be eight monomers in the crystallographic asymmetric unit, corresponding to a VM of 2.52 Å3 Da−1 and a solvent content of 51.1%. This suggests an oligomerization state that differs from those of previously reported type III secretion chaperones. [ABSTRACT FROM AUTHOR]

Probable tRNA-modification GTPase (TrmE) is a guanine nucleotide-binding protein that is conserved between bacteria and humans. GTPase hydrolyzes GTP and plays a pivotal role in signalling pathways. In this study, TrmE from Staphylococcus aureus was overexpressed in Escherichia coli. The enzyme was found to crystallize at 295 K when ammonium sulfate was used as a precipitant. X-ray diffraction data were collected to 2.9 Å resolution from the crystallized enzyme using synchrotron radiation. The crystal was found to belong to the cubic space group I23, with unit-cell parameters a = b = c = 229.47 Å, α = β = γ = 90°. The crystal is likely to contain four monomers in the asymmetric unit, with a corresponding VM of 2.4 Å3 Da−1 and a solvent content of 50%. [ABSTRACT FROM AUTHOR]

The objective of this paper is to study the box-counting dimension of graphs of fractal interpolation functions and harmonic functions on the Sierpiński gasket. Firstly, we give construction of a fractal interpolation function on the Sierpiński gasket and then with the help of fractal interpolation functions we show the existence of fractal functions in the space dom (E) consisting of all finite energy functionals on the Sierpiński gasket. Later, we provide bounds for the box-counting dimension of graphs of some functions belonging to the family of continuous functions which arise as fractal interpolation functions. Moreover, we also obtain bounds for the box-counting dimension of graphs of harmonic functions and piecewise harmonic functions. Also, we obtain upper and lower bounds for the box-counting dimension of graphs of functions that belong to dom (E). [ABSTRACT FROM AUTHOR]

Summary Pro-apoptotic BAX is a cell fate regulator playing an important role in cellular homeostasis and pathological cell death. BAX is predominantly localized in the cytosol, where it has a quiescent monomer conformation. Following a pro-apoptotic trigger, cytosolic BAX is activated and translocates to the mitochondria to initiate mitochondrial dysfunction and apoptosis. Here, cellular, biochemical, and structural data unexpectedly demonstrate that cytosolic BAX also has an inactive dimer conformation that regulates its activation. The full-length crystal structure of the inactive BAX dimer revealed an asymmetric interaction consistent with inhibition of the N-terminal conformational change of one protomer and the displacement of the C-terminal helix α9 of the second protomer. This autoinhibited BAX dimer dissociates to BAX monomers before BAX can be activated. Our data support a model whereby the degree of apoptosis induction is regulated by the conformation of cytosolic BAX and identify an unprecedented mechanism of cytosolic BAX inhibition. [ABSTRACT FROM AUTHOR]

Abstract: The esterase/lipase family (EC 3.1.1.3/EC 3.1.1.1) represents a diverse group of hydrolases that catalyze the cleavage of ester bonds and are widely distributed in animals, plants and microorganisms. Among these enzymes, hormone-sensitive lipases, play a critical role in the regulation of rodent fat cell lipolysis and are regarded as adipose tissue-specific enzymes. Recently, we reported the structural and biological characterization of EstE5 from the metagenome library [K.H. Nam, M.Y. Kim, S.J. Kim, A. Priyadarshi, W.H. Lee, K.Y. Hwang, Structural and functional analysis of a novel EstE5 belonging to the subfamily of hormone-sensitive lipase, Biochem. Biophys. Res. Commun. 379 (2009) 553–556]. The structure of this protein revealed that it belongs to the HSL-family. Here, we report the inhibition of the activity of the HSL-homolog EstE5 protein as determined by the use of esterase/lipase inhibitors. Our results revealed that the EstE5 protein is significantly inhibited by PMSF. In addition, this is the first study to identify the crystal structures of EstE5–PMSF at 2.4 and 2.5Å among the HSL-homolog structures. This structural configuration is similar to that adopted when serine proteases are inhibited by PMSF. The results presented here provide valuable information regarding the properties of the HSL-family. [Copyright &y& Elsevier]

Abstract: Iron is essential for the survival of organisms, but either excess or deficient levels of iron induce oxidative stress, thereby causing cell damage. As a result, iron regulation is essential for proper cell growth and proliferation in most organisms. Bacterioferritin is a ferritin-like family protein that contains a heme molecule and a ferroxidase site at the di-iron center. This protein plays a primary role in intracellular iron storage for iron homeostasis, as well as in the maintenance of iron in a soluble and non-toxic form. Although several bacterioferritin structures have been determined, no structural studies have successfully elucidated the molecular function of the heme molecule and the ferroxidase center. Here, we report the crystal structure of bacterioferritin from Rhodobacter sphaeroides. This protein exists in a roughly spherical configuration via the assembly of 24 subunits. We describe the oligomeric arrangement, ferroxidase center and heme-binding site based on this structure. The protein contains a single iron-binding configuration in the ferroxidase center, which allows for the release of iron by His130 when the protein is in the intermediate state. The heme molecule in RsBfr is stabilized by shifting of the van der Waals interaction center between the porphyrin of the heme and Trp26. We anticipate that further structural analysis will provide a more complete understanding of the molecular mechanisms of members of the ferritin-like family. [Copyright &y& Elsevier]

Abstract: Hormone-sensitive lipase (HSL) plays an important role in the regulation of rodent fat cell lipolysis. It is regarded as an adipose tissue-specific enzyme whose sole metabolic role is the catalysis of hormone-stimulated lipolysis in mammalian cells. In this report we describe the functional and structural analysis of an EstE5 protein from a soil metagenome library. Function analysis results indicated that EstE5 preferentially hydrolyzes short-chain ester compounds, and our kinetic studies revealed the optimal pH and temperature. Based on the structural analysis, we defined the active site and the binding pocket. Structurally, EstE5 belongs to the HSL family and these structural studies may have applications in the production of value-added products, including pharmaceuticals. [Copyright &y& Elsevier]