The outcome of isolated calf muscle vein thrombosis after open reduction and internal fixation for closed intra-articular distal femur fractures: a prospective cohort study.

BACKGROUND: To observe the outcome of isolated calf muscle vein thrombosis (ICMVT) undergoing open reduction and internal fixation (ORIF) for closed intra-articular distal femur fractures (DFFs) and to analyze related factors. METHODS: The study was designed as a prospective clinical cohort study at our hospital. From August 2018 to August 2020,a total of 140 patients with flesh ICMVT after ORIF for closed intra-articular DFFs were collected during hospitalization. After the administration of antithrombotic agents immediately after diagnosis, the location and prognosis of postoperative ICMVT were examined by Duplex ultrasonography (DUS) with a three-month follow-up. There were 29 males and 111 females with the average age of 70.16 ± 8.75 years old. Sonography was used to evaluate the resolution of muscular vein thrombosis at the time point of the third month postoperatively and the results were compared between the two time points. Multivariable analysis was performed to evaluate the relationship between the resolution of ICMVT three months postoperatively and risk factors including age, Body Mass Index (BMI), gender, thrombosis length (> 5 / ≤5 cm), thrombosis diameter(> 0.6/≤0.6 cm), and thrombosis-related biochemistry indices. RESULTS: The postoperative ICMVTs was diagnosed at 5.47 ± 2.46 days after ORIF for closed intra-articular DFFs. At the follow up of 3 months,120 cases was tending to disappear with 88 cases(62.9 %) completely dissolved and 32 cases(22.9 %) partly dissolved. There existed 14 cases (10.0 %) without change on the size and 6 cases (4.2 %) with proximal propagation. Multivariate analysis revealed that thrombus diameter over 0.6 cm (odds ratio [OR], 8.900; 95 % confidence interval [CI]: 3.623-21.865), thrombus length over 5.0 cm (OR, 3.904; 95 % CI, 1.121-13.603), FIB over 3.0 g/L (OR, 3.627; 95 % CI, 1.356-9.689), and D-dimer over 1.0 mg/L (OR, 2.602; 95 % CI, 1.075-6.296) were four independent risk factors of non-completely dissolved ICMVTs. CONCLUSIONS: 85.8 % of ICMVT was tending to disappear at the third months after ORIF for closed intra-articular DFFs. Thrombus diameter, thrombus length, FIB, and D-dimer were four independent risk factors of non-completely dissolved ICMVTs. The Thrombus diameter has a significant effect on the natural course of ICMVTs, especially with diameter larger than 0.6 cm.

On the ionic strength dependence of the electrophoretic mobility: From 2D to 3D slope-plots.

Determining the charge and the nature (small ion, nanoparticle, or polyelectrolyte) of an unknown solute from its electrophoretic characteristics remains a challenging issue. In this work, we demonstrate that, if the knowledge of the effective electrophoretic mobility (µep ) at a given ionic strength is not sufficient to characterize a given solute, the combination of this parameter with (i) the relative decrease of the electrophoretic mobility with the ionic strength (S), and (ii) the hydrodynamic radius (Rh ), is sufficient (in most cases) to deduce the nature of the solute and its charge. These three parameters are experimentally accessible by CZE and Taylor dispersion analysis performed on the same instrumentation. 3D representation of the three aforementioned parameters (µep ; S and Rh ) is proposed to visualize the differences in the electrophoretic behavior between solutes according to their charge and nature. Surprisingly, such 3D slope plot in the case of small ions and nanoparticles looks like a "whale-tail," while polyelectrolyte contour plot represents a rather simple and monotonous map that is independent of solute size. This work also sets how to estimate the effective charge of a solute from a given experimental (S,Rh,µ ep 5 mM ) triplet, which is not possible to obtain unambiguously with only (Rh,µ ep 5 mM ) or (S,µ ep 5 mM ) doublet, where µ ep 5 mM is the effective electrophoretic mobility at 5 mM ionic strength.

Specific ion effects on the electrophoretic mobility of small, highly charged peptides: a modeling study.

In this work, we use coarse-grained modeling to study the free solution electrophoretic mobility of small highly charged peptides (lysine, arginine, and short oligos thereof (up to nonapeptides)) in NaCl and Na2SO4 aqueous solutions at neutral pH and room temperature. The experimental data are taken from the literature. A bead modeling methodology that treats the electrostatics at the level of the nonlinear Poisson Boltzmann equation developed previously in our laboratory is able to account for the mobility of all peptides in NaCl, but not Na2SO4. The peptide mobilities in Na2SO4 can be accounted for by including sulfate binding in the model and this is proposed as one possible explanation for the discrepancy. Oligo arginine peptides bind more sulfate than oligo lysines and sulfate binding increases with the oligo length.

Modeling the electrophoresis of highly charged peptides: application to oligolysines.

The "coarse-grained" bead modeling methodology, BMM, is generalized to treat electrostatics at the level of the nonlinear Poisson-Boltzmann equation. This improvement makes it more applicable to the important class of highly charged macroions and highly charged peptides in particular. In the present study, the new nonlinear Poisson-Boltzmann, NLPB-BMM procedure is applied to the free solution electrophoretic mobility of low molecular mass oligolysines (degree of polymerization 1-8) in lithium phosphate buffer at pH 2.5. The ionic strength is varied from 0.01 to 0.10 M) and the temperature is varied from 25 to 50°C. In order to obtain quantitative agreement between modeling and experiment, a small amount of specific phosphate binding must be included in modeling. This binding is predicted to increase with increasing temperature and ionic strength.

The dependence of the electrophoretic mobility of small organic ions on ionic strength and complex formation.

The ionic strength dependence of the electrophoretic mobility of small organic anions with valencies up to -3 is investigated in this study. Provided the anions are not too aspherical, it is argued that shape and charge distribution have little influence on mobility. To a good approximation, the electrophoretic mobility of a small particle should be equal to that of a model sphere with the same hydrodynamic radius and same net charge. For small ions, the relaxation effect (distortion of the ion atmosphere from equilibrium due to external electric and flow fields) is significant even for monovalent ions. Alternative procedures of accounting for the relaxation effect are examined. In order to account for the ionic strength dependence of a specific set of nonaromatic and aromatic anions in aqueous solution, it is necessary to include complex formation between the anion with species in the BGE. A number of possible complexes are considered. When the BGE is Tris-acetate, the most important of these involves the complex formed between anion and Tris, the principle cation in the BGE. When the BGE is sodium borate, an anion-anion (borate) complex appears to be important, at least when the organic anion is monovalent. An algorithm is developed to analyze the ionic strength dependence of the electrophoretic mobility. This algorithm is applied to two sets of organic anions from two independent research groups.

Modeling the electrophoresis of oligoglycines.

The electrophoretic mobility of low molecular mass oligoglycines is examined in this study using a "coarse-grained" bead modeling methodology [Pei, H., Allison, S. A., J. Chromatogr. A 2009, 1216, 1908-1916]. The advantage of focusing on these peptides is that their charge state is well known [Plasson, R., Cottet, H., Anal. Chem. 2006, 78, 5394-5402] and extensive electrophoretic mobility data are also available in different buffers [Survay, M. A., Goodall, D. M., Wren, S. A. C., Rowe, R. C., J. Chromatogr. A 1996, 741, 99-113] and over a broad range of temperatures [Plasson, R., Cottet, H., Anal Chem. 2005, 77, 6047-6054]. Except for assumptions about peptide secondary structure, the B model has no adjustable parameters. It is concluded that the oligoglycines adopt a random configuration at high temperature (50 degrees C and higher), but more compact conformations at lower temperature. It is proposed that triglycine through pentaglycine adopt compact cyclic structures at low temperature (up to about 25 degrees C) in aqueous solution. At 25 degrees C, buffer interactions are also examined and may or may not influence peptide conformation depending on the buffer species. In a borate buffer at high pH, the mobility data are consistent with complex formation between the oligoglycine and borate anion.

Technetium-99m(V)-dimercaptosuccinic acid osteotropism in Staphylococcus aureus-induced arthritis regulated by glucose-mediated acidification.

OBJECTIVES: To study the possible mechanism of the technetium-99m complex of dimercaptosuccinic acid 99mTc(V)-DMSA accumulation in a model of Staphylococcus aureus-induced bacterial arthritis regulated by glucose. MATERIALS AND METHODS: After making the S. aureus-induced bacterial arthritis model, 14 rabbits were divided into two groups randomly, with one group receiving 6 g/kg 30% glucose administration. Then all the rabbits were injected with 74 MBq 99mTc(V)-DMSA. Whole-body single photon emission computed tomography was applied at different time points. The change of blood pH after blood glucose was also assayed. The percentage of residual activity was evaluated over time in multiple regions of interest, including the inflammatory joint lesions and the contralateral normal joints. Regional joint tissue pH was measured with a needle probe at different times after injecting glucose solution. Forty-two rabbits were divided into six groups to assay the percentage injected dose. RESULTS: 99mTc(V)-DMSA showed a noticeable osteotropic character in bone pathologies. There was no influence of biodistribution of 99mTc(V)-DMSA by glucose loading, but the glucose loading remarkably increased the uptake levels of 99mTc(V)-DMSA in inflammatory joint lesions. A peak difference in glucose-loaded lesion/normal uptake was observed after 6 h. The pH values of the inflammatory joints were noticeably lower than those of the normal joints of the contralateral legs. CONCLUSION: The increased lesion uptake and tissue acidification in the glucose-loaded group supports the hypothesis that glucose acidosis increases DMSA uptake in bacterial arthritis, as has been observed in tumors.

Coarse-grained modeling of the titration and conductance behavior of aqueous fullerene hexa malonic acid (FHMA) solutions.

The coarse-grained continuum primitive model is developed and used to characterize the titration and electrical conductance behavior of aqueous solutions of fullerene hexa malonic acid (FHMA). The spherical FHMA molecule, a highly charged electrolyte with an absolute valence charge as large as 12, is modeled as a dielectric sphere in Newtonian fluid, and electrostatics are treated numerically at the level of the non-linear Poisson-Boltzmann equation. Transport properties (electrophoretic mobilities and conductances) of the various charge states of FHMA are numerically computed using established numerical algorithms. For reasonable choices of the model parameters, good agreement between experiment (published literature) and modeling is achieved. In order to accomplish this, however, a moderate degree of specific binding of principal counterion and FHMA must be included in the modeling. It should be emphasized, however, that alternative explanations are possible. This comparison is made at 25 °C for both Na(+) and Ca(2+) principal counterions. The model is also used to characterize the different charge states and degree of counterion binding to those charge states as a function of pH.

Conductivity and electrophoretic mobility of dilute ionic solutions.

Two complementary continuum theories of electrokinetic transport are examined with particular emphasis on the equivalent conductance of binary electrolytes. The "small ion" model [R.M. Fuoss, L. Onsager, J. Phys. Chem. 61 (1957) 668] and "large ion" model [R.W. O'Brien, L.R. White, J. Chem. Soc. Faraday Trans. 2 (74) (1978) 1607] are both discussed and the "large ion" model is generalized to include an ion exclusion distance and to account in a simple but approximate way for the Brownian motion of all ions present. In addition, the "large ion" model is modified to treat "slip" hydrodynamic boundary conditions in addition to the standard "stick" boundary condition. Both models are applied to the equivalent conductance of dilute KCl, MgCl(2), and LaCl(3) solutions and both are able to reproduce experimental conductances to within an accuracy of several tenths of a percent. Despite fundamental differences in the "small ion" and "large ion" theories, they both work equally well in this application. In addition, both "stick-large ion" and "slip-large ion" models are equally capable of accounting for the equivalent conductances of the three electrolyte solutions.