Archive of Medical Research

A Metallacryptand-Based Manganese(II)-Cobalt(II) Ferrimagnet With a Three-Dimensional Honeycomb Open-Framework Architecture.

Pardo E, Cangussu D, Dul MC, Lescouëzec R, Herson P, Journaux Y, Pedroso EF, Pereira CL, Muñoz MC, Ruiz-García R, Cano J, Amorós P, Julve M, Lloret F.

Laboratoire de Chimie Inorganique et Matériaux Moléculaires, Université Pierre et Marie Curie-Paris 6, UMR 7071, Paris 75252, France, Fax:(+33) 144-273-841.

Optical Analysis of Hg(2+) Ions by Oligonucleotide-Gold-Nanoparticle Hybrids and DNA-Based Machines.

Li D, Wieckowska A, Willner I.

Institute of Chemistry, The Hebrew University of Jerusalem, Jerusalem 91904, Israel, Fax: (+972) 2-6527-715.

Catalytic Properties of Nanoscale Iron-Doped Zirconia Solid-Solution Aerogels.

Nanoscale iron-doped zirconia solid-solution aerogels are prepared via a simple ethanol thermal route using zirconyl nitrate and iron nitrate as starting materials, followed by a supercritical fluid drying process. Structural characteristics are investigated by means of powder X-ray diffraction (XRD), thermal analyses (TG/DTA), N(2) adsorption measurements and diffuse reflectance infrared Fourier transform spectroscopy (DRIFTS). The results show that the resulting iron-doped solid solutions are metastable tetragonal zirconia which exhibit excellent dispersibility and high solubility of iron oxide. Further, when the Fe:(Fe+Zr) ratio x is lower than 0.10, all of the Fe(3+) ions can be incorporated into ZrO(2) by substituting Zr(4+) to form Zr(1-) (x)Fe(x)O(y) solid solutions. Moreover, for the first time, an additional hydroxyl group band that is not present in pure ZrO(2) is observed by DRIFTS for the Zr(Fe)O(2) solid solution. This is direct evidence of Fe(3+) ions incorporated into ZrO(2). These Zr(1-) (x)Fe(x)O(y) solid solutions are excellent catalysts for the solvent-free aerobic oxidation of n-hexadecane using air as the oxidant under ambient conditions. The Zr(0.8)Fe(0.2)O(y) solid-solution catalyst demonstrates the best catalytic properties, with the conversion of n-hexadecane reaching 36.2 % with 48 % selectivity for ketones and 24 % selectivity for alcohols and it can be recycled five times without significant loss of activity.

Chen L, Hu J, Richards RM.

Department of Chemistry and Geochemistry, Colorado School of Mines, Golden CO 80401, USA, Fax: (+1) 303-273-3629.

Transport Processes at alpha-Quartz-Water Interfaces: Insights from First-Principles Molecular Dynamics Simulations.

Car-Parrinello molecular dynamics (CP-MD) simulations are performed at high temperature and pressure to investigate chemical interactions and transport processes at the alpha-quartz-water interface. The model system initially consists of a periodically repeated quartz slab with O-terminated and Si-terminated (1000) surfaces sandwiching a film of liquid water. At a temperature of 1000 K and a pressure of 0.3 GPa, dissociation of H(2)O molecules into H(+) and OH(-) is observed at the Si-terminated surface. The OH(-) fragments immediately bind chemically to the Si-terminated surface while Grotthus-type proton diffusion through the water film leads to protonation of the O-terminated surface. Eventually, both surfaces are fully hydroxylated and no further chemical reactions are observed. Due to the confinement between the two hydroxylated quartz surfaces, water diffusion is reduced by about one third in comparison to bulk water. Diffusion properties of dissolved SiO(2) present as Si(OH)(4) in the water film are also studied. We do not observe strong interactions between the hydroxylated quartz surfaces and the Si(OH)(4) molecule as would have been indicated by a substantial lowering of the Si(OH)(4) diffusion coefficient along the surface. No spontaneous dissolution of quartz is observed. To study the mechanism of dissolution, constrained CP-MD simulations are done. The associated free energy profile is calculated by thermodynamic integration along the reaction coordinate. Dissolution is a stepwise process in which two Si–O bonds are successively broken. Each bond breaking between a silicon atom at the surface and an oxygen atom belonging to the quartz lattice is accompanied by the formation of a new Si–O bond between the silicon atom and a water molecule. The latter loses a proton in the process which eventually leads to protonation of the oxygen atom in the cleaved quartz Si–O bond. The final solute species is Si(OH)(4).

Adeagbo WA, Doltsinis NL, Klevakina K, Renner J.

Lehrstuhl für Theoretische Chemie, Ruhr-Universität Bochum, 44780 Bochum, Germany, Fax: (+44) 20 7848 2420.

Risk factors for leukemic transformation in patients with primary myelofibrosis.

BACKGROUND.: Previous prognostic studies in primary myelofibrosis have focused on risk factors for overall survival and have resulted in the establishment of several prognostic scoring systems. However, to the authors\’ knowledge, information regarding risk factors for leukemic transformation in primary myelofibrosis is limited. METHODS.: The current retrospective study examined clinical variables at the time of diagnosis and specific treatment modalities for their effect on leukemic transformation in 311 patients with primary myelofibrosis who were seen at the Mayo Clinic. RESULTS.: Univariate analysis of parameters at the time of diagnosis revealed a significant association between inferior leukemia-free survival and a peripheral blood blast percentage >/=3 (P < .0001), a platelet count <100 x 10(9)/L (P = .004), a monocyte count >/=1 x 10(9)/L (P = .02), the presence of hypercatabolic symptoms (P = .03), a low hemoglobin level (P = .04), and a high leukocyte count (P = .04). The first 2 parameters were found to maintain their statistical significance during multivariate analysis. Neither leukemia-free nor overall survival was found to be affected by the presence of <3% peripheral blood blasts or JAK2V617F mutation. The evaluation of treatment effect on leukemic transformation unexpectedly revealed a significant and independent association with previous therapy with either erythropoiesis-stimulating agents (P = .004) or danazol (P = .007), even when the aforementioned prognostic indicators at the time of diagnosis were added as covariates to the multivariate model. In contrast, leukemia-free survival was not found to be affected by a treatment history with hydroxyurea, thalidomide, or other drugs. CONCLUSIONS.: A peripheral blood blast percentage >/=3 and/or a platelet count <100 x 10(9)/L at the time of diagnosis were found to be strong and independent predictors of leukemic transformation in patients with primary myelofibrosis. The unexpected association between leukemic transformation and a history of treatment with erythropoiesis-stimulating agents or danazol requires validation by prospective studies. Cancer 2008. (c) 2008 American Cancer Society.

Huang J, Li CY, Mesa RA, Wu W, Hanson CA, Pardanani A, Tefferi A.

Division of Hematology, Mayo Clinic, Rochester, Minnesota.

Twenty-five years of tendon and ligament research.

Twenty-five years ago, the Journal of Orthopaedic Research published its first volume, which included five articles covering topics in tendon and ligament research. Since then, the body of tendon and ligament research has continued to increase exponentially. This review summarizes major advancements in tendon and ligament research since the initial publication of this journal. The purpose of this article is not to provide an in-depth review of all of tendon and ligament research, but instead to provide a concise literature review of some of the major and recurring areas of research. The general topics covered over the last 25 years include tissue properties, tendinopathy, healing, and engineered scaffolds. (c) 2008 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res.

Dourte LM, Kuntz AF, Soslowsky LJ.

McKay Orthopaedic Research Laboratory, University of Pennsylvania, 424 Stemmler Hall, 36th Street and Hamilton Walk, Philadelphia, Pennsylvania 19104‐6081.

Impact of trochanteric heterotopic ossification on measurement of femoral bone density following cemented total hip replacement.

During a study of bone mineral density changes around cemented femoral implants, we recognized heterotopic ossification occurring regularly in a position anterior to the greater trochanter and proximal femur. The aim of this study was to describe the incidence, distribution, and effect of this ossification on periprosthetic DXA scans following primary cemented total hip replacement. One hundre eleven patients underwent postoperative DXA examinations measuring changes in bone mineral density with heterotopic ossification identified and localized on standard radiographs with confirmation using DXA subtraction imaging. Male gender and age within the male group were significantly associated with occurrence of heterotopic ossification (p = 0.003 and 0.046, respectively). Femoral stem type, weight, and body mass index had no significant effect (p = 0.525, 0.372, and 0.243, respectively). Examining the Gruen zones in all patients suggested a median (plus interquartile range) zone 1 density drop of 4% (-12% to +7%). When separated and analyzed for the effect of heterotopic ossification, the 45 patients with heterotopic ossification showed a 2-year density gain of +6% (-5% to +15%), whereas those without heterotopic ossification showed a loss of 8% (-14% to 0%), a significant difference (p < 0.001). Zone 2 also showed a significant difference (p = 0.048). We therefore recommend that affected zones should be identified and excluded from analysis at all time points. Without this precaution, researchers risk underestimating periprosthetic bone loss in their studies and reporting misleading conclusions. (c) 2008 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Ress.

Downing MR, Knox D, Gibson P, Reid DM, Potter A, Ashcroft GP.

Orthopaedic Research Unit, Woodend Hospital, Aberdeen, AB15 6XS, Scotland.

Differential effects of biologic versus bisphosphonate inhibition of wear debris-induced osteolysis assessed by longitudinal micro-CT.

Aseptic loosening of total joint replacements is caused by wear debris-induced osteoclastic bone resorption, for which bisphosphonates (BPs) and RANK antagonists have been developed. Although BPs are effective in preventing metabolic bone loss, they are less effective for inflammatory bone loss. Because this difference has been attributed to the antiapoptotic inflammatory signals that protect osteoclasts from BP-induced apoptosis, but not RANK antagonists, we tested the hypothesis that osteoprotegerin (OPG) is more effective in preventing wear debris-induced osteolysis than zoledronic acid (ZA) or alendronate (Aln) in the murine calvaria model using in vivo micro-CT and traditional histology. Although micro-CT proved to be incompatible with titanium (Ti) particles, we were able to demonstrate a 3.2-fold increase in osteolytic volume over 10 days induced by polyethylene (PE) particles versus sham controls (0.49 +/- 0.23mm(3) versus 0.15 +/- 0.067mm(3); p < 0.01). Although OPG and high-dose ZA completely inhibited this PE-induced osteolysis (p < 0.001), pharmacological doses of ZA and Aln were less effective but still reached statistical significance (p < 0.05). Traditional histomorphometry of the sagital suture area of calvaria from both Ti and PE-treated mice confirmed the remarkable suppression of resorption by OPG (p < 0.001) versus the lack of effect by physiological BPs. The differences in drug effects on osteolysis were largely explained by the significant difference in osteoclast numbers observed between OPG versus BPs in both Ti- and PE-treated calvaria; and linear regression analyses that demonstrated a highly significant correlation between osteolysis volume and sagittal suture area versus osteoclast numbers (p < 0.001). (c) 2008 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res.

Tsutsumi R, Hock C, Bechtold CD, Proulx ST, Bukata SV, Ito H, A Awad H, Nakamura T, O\’Keefe RJ, Schwarz EM.

The Center for Musculoskeletal Research, University of Rochester, 601 Elmwood Avenue, Box 665, Rochester, New York 14642‐0001.

Age and pattern of the onset of differential growth among growth plates in rats.

Differential growth is the phenomenon whereby growth plates in the same individual at the same time all have uniquely different axial growth velocities. Differential growth is clearly present in the adolescent skeleton. In this study we ask two questions. When and by what pattern does the phenomenon of differential growth begin? Second, to what extent are the development of differential growth velocities correlated with changes in hypertrophic chondrocyte volume and/or with changes in chondrocytic production/turnover? Four growth plates (proximal and distal radial; proximal and distal tibial) were studied at 24 different time points in Long-Evans rats between the 17th gestational day (when differential growth does not exist) and postnatal day 27 (when differential growth is well established). Growth velocities were measured using fluorochrome labeling. Using stereological methodology, multiple chondrocytic kinetic parameters were measured for all growth plates. Elongation of the proximal radial growth plate decreases relative to elongation in the other three growth plates in the late fetal phase. Differential growth is fully expressed at postnatal day 13 when the other three growth plates start to decrease daily elongation at different rates. Differential growth is primarily associated with differences in hypertrophic cell volume manifested when growth deceleration occurs. This study also illustrates that differential growth is superimposed on systemic regulators that affect all growth plates simultaneously. The most dramatic illustration of this is the sharp decline in growth velocity in all four growth plates that occurs perinatally. (c) 2008 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res.

Wilsman NJ, Bernardini ES, Leiferman E, Noonan K, Farnum CE.

Department of Comparative Biosciences, University of Wisconsin–Madison, Madison, Wisconsin 53706.

Radiographic analysis of femoroacetabular impingement with Hip(2)norm-reliable and validated.

The purpose of this study was to validate the accuracy, consistency, and reproducibility/reliability of a new method for correction of pelvic tilt and rotation of radiographic hip parameters for pincer type of femoroacetabular impingement on an anteroposterior pelvic radiograph. Thirty cadaver hips and 100 randomized, blinded AP pelvic radiographs were used for investigation. To detect the software accuracy, the calculated femoral head coverage and classic hip parameters determined with our software were compared to reference measurements based on CT scans or conventional radiographs in a neutral orientation as gold standard. To investigate software consistency, differences among the different parameters for each cadaver pelvis were calculated when reckoned back from a random to the neutral orientation. Intra- and interobserver comparisons were used to analyze the reliability and reproducibility of all parameters. All but two parameters showed a good-to-very good accuracy with the reference measurements. No relevant systematic errors were detected in the Bland-Altman analysis. Software consistency was good-to-very good for all parameters. A good-to-very good reliability and reproducibility was found for a substantial number of the evaluated radiographic acetabular parameters. The software appears to be an accurate, consistent, reliable, and reproducible method for analysis of acetabular pathomorphologies. (c) 2008 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res.

Tannast M, Mistry S, Steppacher SD, Reichenbach S, Langlotz F, Siebenrock KA, Zheng G.

Department of Orthopaedic Surgery, Inselspital, University of Bern, Freiburgstrasse, 3010 Bern, Switzerland.