In vitro activities of co-amoxiclav at concentrations achieved in human serum against the resistant subpopulation of heteroresistant Staphylococcus aureus: a controlled study with vancomycin

The effects of concentrations that simulated those in human serum after a single intravenous dose of amoxicillin (2 g), amoxicillin-clavulanic acid (2,000 and 200 mg, respectively), or vancomycin (500 mg), on the viability and beta-lactamase activity of two isogenic (beta-lactamase and non-beta-lactamase producer) heteroresistant Staphylococcus aureus strains were studied in an in vitro pharmacodynamic model. A reduction of > or = 97% of the initial inoculum was obtained with vancomycin and amoxicillin-clavulanic acid against both strains, with respect to the total bacterial population and the oxacillin-resistant subpopulation. The same pattern was observed with amoxicillin and the beta-lactamase-negative strain. beta-Lactamase activity in the beta-lactamase-positive strain changed over time parallel to viability, decreasing with amoxicillin-clavulanic acid or vancomycin and increasing in the amoxicillin and control groups. Clavulanic acid concentrations achievable in serum that changed over time allowed amoxicillin to act against the beta-lactamase-producing methicillin-resistant S. aureus to a similar extent as vancomycin.     

The use of ceramic onlays for restoring the occlusal surface of the teeth

Computer-aided milling of ceramic insertions helped more effectively repair the masticatory surface of teeth, minimize the incidence of errors, rule out the laboratory stage of making the insertions and the technological errors made at this stage, retain physical and mechanical characteristics of ceramics, optimize marginal adherence of the insertion to the tooth, retain the height of the lower part of the face, and thus prevent the maxillodental dysfunction.     

镀锌焊接钢丝网水泥在一种模拟海洋环境中的疲劳特性

使正常养护２８ｄ的７０个镀锌焊接钢丝网水泥试件持续受弯，最外层钢丝的计算应力达到腐蚀下容许值２０７Ｎ／ｍｍ＾２，再放入自制的以７０℃干燥６０ｍｉｎ和４３℃，３．５％ＮａＣｌ溶液浸渍３０ｍｉｎ为一周期的忆速模拟海洋环境实验系统中，分别承受荷载－腐蚀共同作用１、３、７和１８个月（４８０￣８６４０个周期），再对这些试件进行弯曲疲劳－腐蚀试验。分析评估了影响钢丝网水泥抗荷载－腐蚀性能的因素，给出了破坏概率     

Cytosolic thiamine triphosphatase from bovine brain. 1. Regulation of enzyme activity

The steady-state kinetics of the ThTP hydrolysis by thiamine triphosphatase (EC 3.6.1.28) from bovine brain testified to the presence of two kinetically significant conformational states of the protein, their equilibrium being determined by the substrate concentration. The ThTPase isomeric forms had different activities, affinities for ThTP and activation energies. The form with high affinity for the substrate was characterized by the Km and Vmax values of 43 microM and 9.9 mumol.s-1.mg-1 whereas for the form with lower affinity these values were equal to 298 microM and 19.3 mumol.s-1.mg-1, respectively. The activation energies of the ThTP hydrolysis reactions were 85.3 and 47.1 kJ.mol-1. Several mechanisms of the enzyme activity regulation in the cell are suggested. One of the mechanisms is related to the allosteric ThTP effect inducing reversible transition of the protein to a more active conformational state, while the others include the inhibition activity by ATP and the activation of ThTP-ase by Mg2+ free ions.     

Iterative detection for multicarrier transmission employing time-frequency concentrated pulses

We consider multicarrier transmission schemes in which the elementary signal pulses relate to the elements of a Weyl-Heisenberg system, i.e., resulting from a prototype function shifted in time and frequency. The overlapping of the information-bearing signal parts at the output of doubly dispersive channels and the resulting interference are confined by utilizing a prototype function whose energy is concentrated in both time and frequency. We derive a symbol detector which first calculates a sufficient statistic for the unknown data symbols from the linearly combined output signals of a filter bank, and second, performs an iterative maximization of the likelihood function. The presented receiver takes full advantage of the confined pulse overlapping to limit the computational effort. An analysis of the computational complexity and bit-error rate performance of the iterative detection scheme is provided for wide-sense stationary uncorrelated scattering channels.     

Prolonged response of multicentric reticulohistiocytosis to low dose methotrexate

We describe a case of multicentric reticulohistiocytosis complicated by central retinal vein thrombosis and trigeminal neuropathy. A variety of treatment modalities were tried in this patient. Both skin disease and arthritis responded to low dose methotrexate over 8 years of followup. Graduated compression gloves produced an excellent cosmetic improvement in the disfiguring skin lesions.     

Studies of small GTPase Rab7 association with endosomes of cells expressing normal and mutant forms of epidermal growth factor receptors

A study was made of an association of small GTPase Rab7, commonly considered as a marker of late endosomes, with endosomal compartments of cells expressing EGF receptor with different ability to be sorted for degradative pathway. It was found that in cells HER14, expressing normal EGF receptor, Rab7 was associated with both early and late endosomes and the extent of association correlated with the number of EGF-receptor complexes in the specific endosomal fraction. Cels with a receptor, lacking major sites of autophosphorylation by deletion of 126 C-terminal residues (CD126), demonstrated a low efficiency of EGF-receptor sorting to late endosomes and decreased association dynamics with Rab7. Interaction of Rab7 with endosomes of cells expressing kinase negative receptors (K721) was found to be minimal. At the same time, in cells Cd126 and K721 with a low sorting efficiency Rab7 was mainly associated with early endosomes. These data favor Rab7 involvement in mediating early-to-late endosomal transition.     

Variational image reconstruction from arbitrarily spaced samples: a fast multiresolution spline solution.

We propose a novel method for image reconstruction from nonuniform samples with no constraints on their locations. We adopt a variational approach where the reconstruction is formulated as the minimizer of a cost that is a weighted sum of two terms: (1) the sum of squared errors at the specified points and (2) a quadratic functional that penalizes the lack of smoothness. We search for a solution that is a uniform spline and show how it can be determined by solving a large, sparse system of linear equations. We interpret the solution of our approach as an approximation of the analytical solution that involves radial basis functions and demonstrate the computational advantages of our approach. Using the two-scale relation for B-splines, we derive an algebraic relation that links together the linear systems of equations specifying reconstructions at different levels of resolution. We use this relation to develop a fast multigrid algorithm. We demonstrate the effectiveness of our approach on some image reconstruction examples.