Mapping of contributions from collateral ligaments to overall knee joint constraint: an experimental cadaveric study.

Understanding the contribution of the soft-tissues to total joint constraint (TJC) is important for predicting joint kinematics, developing surgical procedures, and increasing accuracy of computational models. Previous studies on the collateral ligaments have focused on quantifying strain and tension properties under discrete loads or kinematic paths; however, there has been little work to quantify collateral ligament contribution over a broad range of applied loads and range of motion (ROM) in passive constraint. To accomplish this, passive envelopes were collected from nine cadaveric knees instrumented with implantable pressure transducers (IPT) in the collateral ligaments. The contributions from medial and lateral collateral ligaments (LCL) were quantified by the relative contribution of each structure at various flexion angles (0-120 deg) and compound external loads (±10 N m valgus, ±8 N m external, and ±40 N anterior). Average medial collateral ligament (MCL) contributions were highest under external and valgus torques from 60 deg to 120 deg flexion. The MCL showed significant contributions to TJC under external torques throughout the flexion range. Average LCL contributions were highest from 0 deg to 60 deg flexion under external and varus torques, as well as internal torques from 60 deg to 110 deg flexion. Similarly, these regions were found to have statistically significant LCL contributions. Anterior and posterior loads generally reduced collateral contribution to TJC; however, posterior loads further reduced MCL contribution, while anterior loads further reduced LCL contribution. These results provide insight to the functional role of the collaterals over a broad range of passive constraint. Developing a map of collateral ligament contribution to TJC may be used to identify the effects of injury or surgical intervention on soft-tissue, and how collateral ligament contributions to constraint correlate with activities of daily living.

Variations in medial-lateral hamstring force and force ratio influence tibiofemoral kinematics.

A change in hamstring strength and activation is typically seen after injuries or invasive surgeries such as anterior cruciate reconstruction or total knee replacement. While many studies have investigated the influence of isometric increases in hamstring load on knee joint kinematics, few have quantified the change in kinematics due to a variation in medial to lateral hamstring force ratio. This study examined the changes in knee joint kinematics on eight cadaveric knees during an open-chain deep knee bend for six different loading configurations: five loaded hamstring configurations that varied the ratio of a total load of 175 N between the semimembranosus and biceps femoris and one with no loads on the hamstring. The anterior-posterior translation of the medial and lateral femoral condyles' lowest points along proximal-distal axis of the tibia, the axial rotation of the tibia, and the quadriceps load were measured at each flexion angle. Unloading the hamstring shifted the medial and lateral lowest points posteriorly and increased tibial internal rotation. The influence of unloading hamstrings on quadriceps load was small in early flexion and increased with knee flexion. The loading configuration with the highest lateral hamstrings force resulted in the most posterior translation of the medial lowest point, most anterior translation of the lateral lowest point, and the highest tibial external rotation of the five loading configurations. As the medial hamstring force ratio increased, the medial lowest point shifted anteriorly, the lateral lowest point shifted posteriorly, and the tibia rotated more internally. The results of this study, demonstrate that variation in medial-lateral hamstrings force and force ratio influence tibiofemoral transverse kinematics and quadriceps loads required to extend the knee. © 2016 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 34:1707-1715, 2016.

Modifying the properties of platinum (IV) complexes in order to increase biological effectiveness.

The preparation of a series of novel Pt(IV) complexes containing the anionic polyfluoroaryl ligands, 2,3,5,6-tetrafluorophenyl (p-HC6F4), 2,3,5,6-tetrafluoro-4-methoxyphenyl (p-MeOC6F4) and pentafluorophenyl (C6F5) are described. The crystal structure of a representative complex, [Pt(p-MeOC6F4)2(O2CEt)2(en)] (en = ethane-1,2-diamine) was determined and confirms the trans arrangement of the carboxylato ligands. Reduction potentials of the series of complexes reveal that replacement of equatorial chloro ligands by polyfluoroaryl ligands makes reduction substantially more difficult. They also confirm previously reported trends in that complexes having axial carboxylato ligands are more readily reduced than those having axial hydroxo ligands. Reduction potentials and in vitro activities showed no obvious correlations. Moderate to high activity was observed for many complexes in the series, including some of those that were very difficult to reduce.

The surgical management of intra-abdominal inflammatory conditions during pregnancy.

The timely diagnosis and treatment of intra-abdominal conditions during pregnancy can challenge the surgical consultant. Familiarity with the anatomic and physiologic changes present in normal pregnancy is essential, as is the knowledge of relative risk by trimester. The general surgeon will be called upon to diagnose and treat appendicitis, biliary tract disease (including pancreatitis), and liver disease. Knowledge of how these conditions become manifest is essential. The surgical consultant should be aware that virtually all complications that occur in the management of these conditions are caused by delay in the detection of the disease process.

The encapsulation of ferrocyanide by copper(II) complexes of tripodal tetradentate ligands. Novel H-bonding networks incorporating heptanuclear and pentanuclear heterometallic assemblies.

Substitution of the weakly binding aqua ligand in [Cu(tren)OH2](2+) and [Cu(tpa)OH2](2+) (tren = tris(2-aminoethyl)amine; tpa = tris(2-pyridylmethyl)amine) by a cyano ligand on ferricyanide results in the assembly of heteropolynuclear cations around the cyanometalate core. In water, the reduction of the Fe(III) core to Fe(II) generates complexes that feature heteropolycations in which ferrocyanide is encapsulated by the Cu(II) moieties: [(Cu(tpa)CN)6Fe][ClO4]8-3H2O 1, [(Cu(tren)CN)6Fe][ClO4]8-10H2O 2, [(Cu(tren)CN)6Fe][Fe(CN)6]2[ClO4]2-15.8H2O 3, and [(Cu(tren)CN)6Fe][(Cu(tren)CN)4Fe(CN)2][Fe(CN)6)]4-6DMSO-21H2O 4. The formation of discrete molecules, in preference to extended networks or polymeric structures, has been encouraged through the use of branched tetradentate ligands in conjunction with copper(II), a metal center with the propensity to form five-coordinate complexes. Complex 3 crystallizes in the monoclinic space group P2(1)/c (#14) with a = 14.8674(10), b = 25.9587(10), c = 27.5617(10) A, beta = 100.8300(10) degrees, and Z = 4, and it is comprised of almost spherical heptanuclear cations, [(Cu(tren)CN)6Fe](8+), whose charge is balanced by two ferricyanide and two perchlorate counteranions. Complex 4 crystallizes in the triclinic space group P1 (# 1) with a = 14.8094(8), b = 17.3901(7), c = 21.1565(11) A, alpha = 110.750(3), beta = 90.206(2), gamma = 112.754(3) degrees, and Z = 1, and it is comprised of the heptanuclear [(Cu(tren)CN)6Fe](8+) cation and pentanuclear [(Cu(tren)CN)4Fe(CN)2](4+) cation, whose terminal cyano ligands are oriented trans to each other. The charge is balanced exclusively by ferricyanide counteranions. In both complexes, H-bonding interactions between hydrogens on primary amines of the tren ligand, terminal cyano groups of the ferricyanide counterions, and the solvent of crystallization generate intricate 3D H-bonding networks.

Giant pseudomalignant granuloma.

A patient who developed rapidly growing, multicentric, cutaneous tumors clinically resembling pyogenic granuloma is reported. In spite of the fact that the local lesions expanded rapidly and contained cytologically "malignant" cells which appeared to invade dermal vessels, the patient had a benign clinical course. The differential diagnosis of "giant pseudomalignant granuloma" is discussed.

IL-9-deficient mice establish fundamental roles for IL-9 in pulmonary mastocytosis and goblet cell hyperplasia but not T cell development.

Interleukin-9 is a cytokine produced by Th2 cells and is a candidate gene for asthma and atopy. We have generated IL-9-deficient mice to delineate the specific roles of IL-9 in Th2 responses. Using a pulmonary granuloma model, we have demonstrated a distinct requirement for IL-9 in the rapid and robust generation of pulmonary goblet cell hyperplasia and mastocytosis in response to lung challenge. In contrast, eosinophilia and granuloma formation were not affected. IL-9 was not required for T cell development or differentiation, the generation of naive or antigen-driven antibody responses, or the expulsion of the intestinal parasitic nematode Nippostrongylus brasiliensis. Thus, deletion of IL-9 manifests as a highly defined phenotype in Th2 responses modulating mucus production and mast cell proliferation.

Mechanistic investigations on the reaction between 1,2-dioxines and bulky stabilized phosphorus ylides: an efficient route to closely related cyclopropane stereoisomers.

The bulky stabilized ylides (2a-d) react with a range of 1,2-dioxines (1a-d) to afford the diversely functionalized cyclopropanes 7 in excellent yield and diastereomeric excess. This is in direct contrast to the situation when nonbulky ester ylides are utilized which results in a completely different cyclopropyl series. Through a combination of isolation, spectroscopic, temperature, and deuterium and additive effects studies, the mechanism of cyclopropane formation from this second pathway can be proposed. Importantly, enolate quenching of the intermediate 1-2lambda(5)-oxaphospholanes 4 prior to collapse results in an equilibrium mixture of intermediates 10 and 11 which have been fully characterized, and their formation is primarily a result of the steric bulk of the stabilized ester ylide. These intermediates (10/11) then collapse further and result in formation of the observed closely related cyclopropyl stereoisomers 7 and 8. Moreover, the addition of LiBr to these reactions allows for the control of which of the two possible cyclopropanation pathways will be dominant. Finally, optimal protocols that demonstrate the potential of this new cyclopropanation methodology for the ready construction of closely related cyclopropyl stereoisomers are presented.

Structural, spectroscopic, and electrochemical studies of binuclear manganese(II) complexes of bis(pentadentate) ligands derived from bis(1,4,7-triazacyclononane) macrocycles.

Structural, electrochemical, ESR, and H2O2 reactivity studies are reported for [Mn(dmptacn)Cl]ClO4 (1, dmptacn = 1,4-bis(2-pyridylmethyl)-1,4,7-triazacyclononane) and binuclear complexes of bis(pentadentate) ligands, generated by attaching 2-pyridylmethyl arms to each secondary nitrogen in bis(1,4,7-triazacyclononane) macrocycles and linked by ethyl (tmpdtne, [Mn2(tmpdtne)Cl2](ClO4)2.2DMF, 2), propyl (tmpdtnp, [Mn2(tmpdtnp)Cl2](ClO4)2.3H2O, 3), butyl (tmpdtnb, [Mn2(tmpdtnb)Cl2](ClO4)2.DMF.2H2O, 4), m-xylyl (tmpdtn-m-X, [Mn2(tmpdtn-m-X)-Cl2](ClO4)2, 5) and 2-propanol (tmpdtnp-OH, [Mn2(tmpdtnp-OH)Cl2](ClO4)2, 6) groups. 1 crystallizes in the orthorhombic space group P2(1)2(1)2(1) (No. 19) with a = 7.959(7) A, b = 12.30(1) A, and c = 21.72(2) A; 2, in the monoclinic space group P2(1)/c (No. 14) with a = 11.455(4) A, b = 15.037(6) A, c = 15.887(4) A, and beta = 96.48(2) degrees; 3, in the monoclinic space group P2(1)/c (No. 14) with a = 13.334(2) A, b = 19.926(2) A, c = 18.799(1) A, and beta = 104.328(8) degrees; and [Mn2(tmpdtnb)Cl2](ClO4)2.4DMF.3H2O (4'), in the monoclinic space group P2(1)/n (No. 14) with a = 13.361(3) A, b = 16.807(5) A, c = 14.339(4) A, and beta = 111.14(2) degrees. Significant distortion of the Mn(II) geometry is evident from the angle subtended by the five-membered chelate (ca. 75 degrees) and the angles spanned by trans donor atoms (< 160 degrees). The Mn geometry is intermediate between octahedral and trigonal prismatic, and for complexes 2-4, there is a systematic increase in M...M distance with the length of the alkyl chain. Cyclic and square-wave voltammetric studies indicate that 1 undergoes a 1e- oxidation from Mn(II) to Mn(III) followed by a further oxidation to MnIV at a significantly more positive potential. The binuclear Mn(II) complexes 2-5 are oxidized to the Mn(III) state in two unresolved 1e- processes [MnII2-->MnIIMnIII-->MnIII2] and then to the MnIV state [MnIII2-->MnIIIMnIV-->MnIV2]. For 2, the second oxidation process was partially resolved into two 1e- oxidation processes under the conditions of square-wave voltammetry. In the case of 6, initial oxidation to the MnIII2 state occurs in two overlapping 1e- processes as was found for 2-5, but this complex then undergoes two further clearly separated 1e- oxidation processes to the MnIIIMnIV state at +0.89 V and the MnIV2 state at +1.33 V (vs Fc/Fc+). This behavior is attributed to formation of an alkoxo-bridged complex. Complexes 1-6 were found to catalyze the disproportionation of H2O2. Addition of H2O2 to 2 generated an oxo-bridged mixed-valent MnIIIMnIV intermediate with a characteristic 16-line ESR signal.