Semitendinosus and gracilis transfer for treatment of medial collateral ligament injury of total knee arthroplasty.

OBJECTIVE: The objective of the study is to evaluate the clinic effectiveness of semitendinosus and gracilis transfer for the treatment of medial collateral ligament (MCL) injury of total knee arthroplasty (TKA). PATIENTS AND METHODS: From March 2009 to May 2014, a series of 11 patients with MCL injuries of primary TKA were treated by semitendinosus and gracilis transfer. Another 18 patients (21 knees) were recruited as control group. The two groups of patients were comparable for gender, age, body mass index, varus knee deformity, KSS score, joint activity degree and type of prosthesis comparison without significant difference (p > 0.05). All the patients were regularly followed-up using the American Knee Society Scoring System (KSS). RESULTS: No patient of either group reported impaired wound healing, joint instability, pain, prosthesis loosening and other complications. At the final follow-up, the mean knee objective score and the functional score of the injury group include (89.82 ± 3.76) points and (89.54 ± 3.50) points, respectively. The control group includes (90.19 ± 3.39) and (90 ± 3.53) points. They were significantly higher than the preoperative conditions. The difference was not statistically significant. The difference of KSS score was not statistically significant (t = 0.158, p = 0.877; t = 0.820, p = 0.432). CONCLUSIONS: The semitendinosus and gracilis transfer are reliable for the treatment of MCL injury of TKA. The semitendinosus and gracilis are close to the knee MCL, which can effectively improve knee function.

[Effects of chrysin on sphere formation and CK2α expression of ovarian cancer stem-like cells derived from SKOV3 cell line].

OBJECTIVE: To investigate whether inhibitory effect of chrysin on sphere formation of ovarian cancer stem-like cells(spheroids derived from human ovarian cancer SKOV3 cell line ) is involved in the down-regulating of the protein expression of casein kinase CK2α. METHODS: SKOV3-derived ovarian cancer stem-like cells obtained by suspension culture in stem cell-condition medium using ultra-low adhesion plate were treated with various concentrations (5.0, 10.0 and 20.0 µmol/L) of chrysin. Sphere formation assay was used to determine the sphere forming rate of SKOV3-derived ovarian cancer stem-like cells. Western blot was used to analyze the protein expressions of CK2α and cancer stem cell markers CD133 and CD44. Silence of CK2α by siRNA and ectopic expression of CK2α by transfection with pcDNA3.1-CK2α plasmid were used to explore the mechanism underlying the effect of chrysin on sphere formation of SKOV3-derived ovarian cancer stem-like cells. RESULTS: Chrysin (5.0, 10.0 and 20.0 µmol/L) significantly reduced the sphere forming rate of SKOV3-derived ovarian cancer stem-like cells, in a concentration-dependent manner (22.3%±2.5% vs 14.7%±2.1%, 8.6%± 1.7% and 3.8% ± 1.1% respectively; P<0.05). In addition, chrysin (5.0, 10.0 and 20.0 µmol/L) obviously down-regulated the protein expressions of CK2α, CD133 and CD44 in SKOV3-derived ovarian cancer stem-like cells. In combination with CK2α siRNA transfection and chrysin synergistically decreased sphere formation (P<0.05) and the protein expressions of CK2α, CD133 and CD44 in SKOV3-derived ovarian cancer stem-like cells. However, transfection with pcDNA3.1-CK2α plasmid attenuated inhibitory effects of chrysin on sphere formation capability and the expressions of CK2α, CD133 and CD44 of SKOV3-derived ovarian cancer stem-like cells. CONCLUSION: Down-regulation of CK2α protein expression is involved in the inhibition effect of chrysin on the sphere formation capability of SKOV3-derived ovarian cancer stem-like cells.

Short axis contact in the chaining of ellipsoidal particles of polar molecule dominated electrorheological fluid.

We simulate the effect of the chaining direction of ellipsoidal particles of polar molecule dominated electrorheological (PM-ER) fluids using commercially available COMSOL Multiphysics® software for the distribution of electric field and the total electrostatic energy. It is proved that adding ferroelectric materials to the channels parallel to the short axis would make the short axis parallel to the field direction when the ellipsoidal particles are chained under an electric field. According to our simulation, while the concentration of the channels stays constant, the greater the dielectric constant of the inserted material, the stronger the maximum local electric field will be.

Isolated renal metastasis after colon cancer.

Renal infiltration of colon adenocarcinoma is a rare event. The authors present the case report of a 52-year-old female who had a high carcinoembryonic antigen level 18 months after right hemicolectomy and a chemotherapy regimen to treat transverse colon adenocarcinoma. The patient presented cancer recurrence after 12 months, and underwent a paraaortic lymphadenoctomy and a second adjuvant chemotherapy with the folfox regimen. Abdomen computerized tomography revealed two solid masses in the right kidney, without evidence of any other metastatic sites. A nephrectomy was performed in the right kidney followed by adjuvant chemotherapy.

Structure of electrorheological fluids under an electric field and a shear flow: experiment and computer simulation.

It is known that macroscopic properties of colloidal suspensions are often determined by the microstructure of the particles in the suspensions, depending on the interparticle, Brownian, and hydrodynamic (if any) forces. We take electrorheological (ER) fluids as an example. By using a computer simulation and an experimental approach, we investigate the structure of ER fluids subjected to both an electric field and a shear flow. The microstructure evolution from random structure, to chains, and then to stable lamellar patterns, observed in the experiments, agrees very well with that obtained in the simulations. It is shown that the formation of such lamellar patterns originates from the difference between the dipole moment induced in the particles suspended in the ER fluids without shear and the one with shear. The results on the relaxation process of structural formation and the internal structure of layers are also presented. Thus, it seems possible to achieve various structures and hence desired macroscopic properties of colloidal suspensions by adjusting external fields and, simultaneously, a shear flow.

The lux autoinducer-receptor interaction in Vibrio harveyi: binding parameters and structural requirements for the autoinducer.

To assess the binding parameters and the structure-function relationship of the Vibrio harveyi lux autoinducer, N-(D-3-hydroxybutanoyl)homoserine lactone (D-HBHL), to light emission, a series of acylhomoserine lactone analogues were synthesized and their effects on the stimulation of luminescence of an autoinducer-deficient mutant of V. harveyi, D1, examined. Of the analogues with 3-hydroxyacyl chains, only N-(3-hydroxyvaleryl)homoserine lactone (HVHL) could act as an inducer, with about 85% of the potency of D-HBHL in stimulation of luminescence; the apparent Kd of the putative receptor for HVHL was 3.8 microM, close to that for the natural autoinducer (1.4 microM). Analogues with longer 3-hydroxyacyl chains, N-(3-hydroxyhexanoyl)homoserine lactone and N-(3-hydroxyheptanoyl)homoserine lactone, acted as competitive inhibitors of HBHL with apparent KI values of 77 and 53 microM respectively. Replacement of the 3-hydroxybutanoyl moiety with a 3-methylbutanoyl or 3-methoxybutanoyl group created weak competitive inhibitors, N-(isovaleryl)- and N-(3-methoxybutanoyl)- homoserine lactones, with apparent KI values of 150 and 360 microM respectively. Two other analogues, N-(2-hydroxybutanoyl)- and N-(4-hydroxybutanoyl)-homoserine lactone, could neither stimulate nor inhibit luminescence. The approach used in these studies to demonstrate binding of autoinducer analogues at the same site, as well as measurement of the relative dissociation constant, may be of value in analysing analogues activating or inhibiting luminescence and other processes that are under control of acylhomoserine lactone autoregulators.

Growth and developmental functions of a human immunodeficiency virus Tat-binding protein/26S protease subunit homolog from Dictyostelium discoideum.

We have characterized a newly identified gene from Dictyostelium discoideum, DdTBP alpha, that encodes a member of the family of eukaryotic proteins. These proteins contain a conserved ATPase domain, include subunits of the 26S protease subunit, and are homologous to the mammalian human immunodeficiency virus Tat-binding protein TBP1. While information indicates that some family members are involved in the regulation of transcription in mammalian and yeast cells during growth, these proteins are also involved in other cellular functions, and nothing is known about their possible function in multicellular development. The Dictyostelium DdTBP alpha gene is developmentally regulated, with its expression at the highest levels occurring during growth and early development. The gene is present in two copies in the genome. Disruption of one copy by homologous recombination leads to aberrant morphogenesis, which lasts from the formation of the first finger until the onset of culmination. The gene appears to be essential for growth since we were unable to obtain a complete null phenotype and since expression of an inducible antisense construct in the partial null background resulted in cell death. Expression of the antisense construct during development accentuated the partial null phenotype and also resulted in very abnormal fruiting bodies. Overexpression of DdTBP alpha from its own promoter leads to very large multinucleated vegetative cells when the cells are grown in suspension culture. When the cells are plated onto petri dishes in growth medium, they rapidly split into multiple cells containing one to two nuclei, in a manner similar to that of wild-type cells. Overexpressing cells are significantly delayed in forming a multicellular aggregate, but development proceeds normally once the first finger stage is reached. The results indicate that DdTBP alpha plays an important role in regulating both growth and morphogenesis in D. discoideum.

Proximal and distal sites bind LuxR independently and activate expression of the Vibrio harveyi lux operon.

The LuxR regulatory protein of Vibrio harveyi as well as the autoinducer molecule, N-(3-hydroxybutanoyl) homoserine lactone, are known to be required for expression of luminescence. Although LuxR has been implicated in the activation of the promoter of the lux operon of V. harveyi, and can bind to two distinct sites upstream of the transcription initiation start site, its mode of action is unknown. In the present experiments, mobility shift assays were used to demonstrate that LuxR bound to the distal and proximal sites in an independent rather than co-operative interaction with a much tighter binding to the distal site. Deletion mutation analyses of DNA upstream of the lux promoter followed by transconjugation into V. harveyi in trans using the chloramphenicol acetyltransferase (cat) gene as a reporter demonstrated, however, that the proximal site for LuxR was absolutely critical for promoter activation while the distal LuxR site was only necessary for maximum activation. This result was confirmed by mutation of the proximal site which blocked activation of the lux promoter and binding of LuxR to this site, but did not prevent LuxR binding to the distal site.

Biosynthesis of poly-3-hydroxybutyrate in the luminescent bacterium, Vibrio harveyi, and regulation by the lux autoinducer, N-(3-hydroxybutanoyl)homoserine lactone.

Poly-3-hydroxybutyrate (PHB), a biopolymer of important commercial applications, is found in a wide range of Gram-negative and Gram-positive bacteria and cyanobacteria. The present study has resulted in the identification of PHB in the luminescent marine bacteria, Vibrio harveyi, in spite of it being previously classified as PHB-negative. PHB granules with distinct membranes were detected by electron microscopy after fixation and staining of V. harveyi cells with malachite green. Analyses by gas chromatography, nuclear magnetic resonance, infrared, and ultraviolet spectroscopy clearly established the presence of PHB. The synthesis of PHB in V. harveyi was found to be under cell density regulation with the levels increasing from 0 (< 0.2) to 26 mg of PHB/g of dry cell weight during growth in a manner analogous to the induction of luminescence in this bacteria. Moreover, synthesis of PHB in V. harveyi was shown to be controlled by the lux autoinducer, N-(3-hydroxybutanoyl)homoserine lactone, providing not only a potential link between luminescence and PHB production but also showing that the lux autoinducer acts as a general signal transductant. These results have also extended the role of homoserine lactones in metabolic regulation to include the control of synthesis of potential energy reserves.

Biosynthesis and stereochemistry of the autoinducer controlling luminescence in Vibrio harveyi.

Knowledge of the pathway for synthesis of the autoinducer, N-(beta-hydroxybutyryl)-homoserine lactone (HBHL), controlling luminescence in Vibrio harveyi can provide important information concerning the relationship between the nutrition and physiology of the bacteria and the phenomenon of light emission. In this study, the D and L isomers of the autoinducer containing the stereoisomers of beta-hydroxybutyric acid were synthesized and characterized by proton nuclear magnetic resonance in the presence of a chiral shift reagent, a europium(III) derivative of Tris[3-(heptafluoropropyl-hydroxymethylene)-(+)-camphorato]. By using a newly isolated autoinducer mutant which responds to low physiological concentrations of the autoinducer, it could be shown that autoinducer activity was associated with D-HBHL and not L-HBHL. Blockage of fatty acid biosynthesis by the addition of fatty acids and/or the antibiotic cerulenin to the cells prevented synthesis of the autoinducer as measured by the loss of autoinducer activity and a decrease in the incorporation of labelled acetate into the partially purified autoinducer. These results indicate that fatty acid biosynthesis is necessary for light emission in luminescent bacteria because it controls formation of the lux autoinducer.

Purification and structural identification of an autoinducer for the luminescence system of Vibrio harveyi.

An autoinducer required for the growth-dependent development of luminescence in Vibrio harveyi has been purified, structurally identified, and chemically synthesized. The autoinducer, which is excreted by the cells, was extracted with chloroform from conditioned media in which V. harveyi cells had been grown. The concentrated extract was separated on a silica gel column and the autoinducer activity further purified by thin layer, paper, and high performance liquid chromatography. The structure of the partially purified autoinducer was identified by 1H NMR and mass spectrometry as N-(beta-hydroxybutyryl)homoserine lactone. This compound was chemically synthesized by condensation of beta-hydroxybutyrate with alpha-amino-gamma-butyrolactone hydrobromide using 1-ethyl-3-(3-dimethylaminopropyl)carbodiimide as a carboxyl group activator. The pure synthetic autoinducer gave the characteristic NMR and mass spectra, co-migrated with the natural autoinducer on thin layer plates, and specifically stimulated induction of luminescence of V. harveyi. Light emission of a regulatory dark mutant of V. harveyi could be stimulated over 1000-fold by the addition of N-(beta-hydroxybutyryl)homoserine lactone, reaching intensities comparable to that of the native strain. The similarity in structure of the autoinducer of V. harveyi to that of Vibrio fischeri suggests that the regulation of luminescence induction in these bacteria may be related in spite of their differences in lux gene organization.