Comparison of patient reported outcomes after Triathlon? and Kinemax Plus prostheses

INTRODUCTION

The Triathlon^® (Stryker, Kalamazoo, MI, US) total knee replacement was designed to improve patient function and survivorship. The aim of this study was to determine whether the Triathlon^® prosthesis produces better patient reported outcomes than a previous design by the same manufacturer, the Kinemax Plus.

METHODS

The outcome of 233 knees of patients with a mean age of 68 years (range: 40–80 years) who received the Kinemax Plus prosthesis were compared with the outcomes of 220 knees of patients with a mean age of 70 years (range: 42–90 years) who received the Triathlon^® prosthesis. Data were collected via postal questionnaire prior to surgery as well as at 8–12 weeks and at 1 year following surgery. Validated questionnaires were used including the WOMAC^® (Western Ontario and McMaster Universities) pain and function scales, the Knee injury and Osteoarthritis Outcome Score quality of life scale and the self-administered patient satisfaction scale.

RESULTS

This study found that patients who had the Triathlon^® prosthesis had significantly better pain relief (p<0.0001), function (p=0.028), knee related quality of life (p<0.0001) and satisfaction (p=0.0003) at three months after surgery than those who received the Kinemax Plus prosthesis. In addition, knee related quality of life (p=0.002) and satisfaction (p=0.021) were significantly higher at one year after surgery in Triathlon^® patients.

CONCLUSIONS

The findings suggest that return to function and reduction in pain may occur more quickly in patients with a Triathlon^® prosthesis than in those with the Kinemax Plus.     

Project Kealahou: Improving Hawai‘i's System of Care for At-Risk Girls and Young Women through Gender-Responsive,Trauma-Informed Care

Project Kealahou (PK) is a six-year, federally-funded program aimed at improving services and outcomes for Hawai‘i''s female youth who are at risk for running away, truancy, abuse, suicide, arrest and incarceration. PK builds upon two decades of sustained cross-agency efforts among the state''s mental health, juvenile justice, education, and child welfare systems to promote system-of-care (SOC) principles of community-based, individualized, culturally and linguistically competent, family driven, youth-guided, and evidence-based services. In addition, PK emphasizes trauma-informed and gender-responsive care in serving its target population of females ages 11–18 years who have experienced psychological trauma.Results from the first four years of the implementation of PK in the Department of Health''s (DOH) Child and Adolescent Mental Health Division (CAMHD) highlight the serious familial, socioeconomic, functional, and interpersonal challenges faced by the young women who receive services in Hawai‘i''s SOC. Despite the challenges faced by PK youth and their families, preliminary results of the evaluation of PK show significant improvements across multiple clinical and functional domains of service recipients. A financial analysis indicates that these outcomes were obtained with a minimal overall increase in costs when compared to standard care alone. Overall, these results suggest that PK may offer a cost effective way to improve access, care, and outcomes for at-risk youth and their families in Hawai‘i.     

Optimizing dose and scheduling of filgrastim (granulocyte colony- stimulating factor) for mobilization and collection of peripheral blood progenitor cells in normal volunteers [see comments]

To define an optimal regimen for mobilizing and collecting peripheral blood progenitor cells (PBPC) for use in allogeneic transplantation, we evaluated the kinetics of mobilization by filgrastim (recombinant met- human granulocyte colony-stimulating factor [r-metHuG-CSF]) in normal volunteers. Filgrastim was injected subcutaneously for up to 10 days at a dose of 3 (n = 10), 5 (n = 5), or 10 micrograms/kg/d (n = 15). A subset of volunteers from each dose cohort underwent a 7L leukapheresis on study day 6 (after 5 days of filgrastim). Granulocyte-macrophage colony-forming cell (GM-CFC) numbers in the blood were maximal after 5 days of filgrastim; a broader peak was evident for CD34+ cells between days 4 and 6. The 95% confidence intervals (CI) for mean number of PBPC per milliliter of blood in the three dose cohorts overlapped on each study day. However, on the peak day, CD34+ cells were significantly higher in the 10 micrograms/kg/d cohort than in a pool of the 3 and 5 micrograms/kg/d cohorts. Mobilization was not significantly influenced by volunteer age or sex. Leukapheresis products obtained at the 10 micrograms/kg/d dose level contained a median GM-CFC number of 93 x 10(4)/kg (range, 50 x 10(4)/kg to 172 x 10(4)/kg). Collections from volunteers receiving lower doses of filgrastim contained a median GM- CFC number of 36 x 10(4)/kg (range, 5 x 10(4)/kg to 204 x 10(4)/kg). The measurement of CD34+ cells per milliliter of blood on the day of leukapheresis predicted the total yield of PBPC in the leukapheresis product (r = .87, P < .0001). Assuming a minimum GM-CFC requirement of 50 x 10(4)/kg (based on our experience with autologous PBPC transplantation), all seven leukapheresis products obtained at the 10 micrograms/kg/d dose level were potentially sufficient for allogeneic transplantation purposes. We conclude that in normal donors, filgrastim 10 micrograms/kg/d for 5 days with a single leukapheresis on the following day is a highly effective regimen for PBPC mobilization and collection. Further studies are required to determine whether PBPC collected with this regimen reliably produce rapid and sustained engraftment in allogeneic recipients.     

Modulation of α1β3γ2 GABAA receptors expressed in X. laevis oocytes using a propofol photoswitch tethered to the transmembrane helix

Tethered photoswitches are molecules with two photo-dependent isomeric forms, each with different actions on their biological targets. They include reactive chemical groups capable of covalently binding to their target. Our aim was to develop a β-subunit-tethered propofol photoswitch (MAP20), as a tool to better study the mechanism of anesthesia through the GABA_A α1β3γ2 receptor. We used short spacers between the tether (methanethiosulfonate), the photosensitive moiety (azobenzene), and the ligand (propofol), to allow a precise tethering adjacent to the putative propofol binding site at the β⁺α⁻ interface of the receptor transmembrane helices (TMs). First, we used molecular modeling to identify possible tethering sites in β3TM3 and α1TM1, and then introduced cysteines in the candidate positions. Two mutant subunits [β3(M283C) and α1(V227C)] showed photomodulation of GABA responses after incubation with MAP20 and illumination with lights at specific wavelengths. The α1β3(M283C)γ2 receptor showed the greatest photomodulation, which decreased as GABA concentration increased. The location of the mutations that produced photomodulation confirmed that the propofol binding site is located in the β⁺α⁻ interface close to the extracellular side of the transmembrane helices. Tethering the photoswitch to cysteines introduced in the positions homologous to β3M283 in two other subunits (α1W288 and γ2L298) also produced photomodulation, which was not entirely reversible, probably reflecting the different nature of each interface. The results are in agreement with a binding site in the β⁺α⁻ interface for the anesthetic propofol.

While photoswitches have been a popular topic in numerous reviews (1), their application in research is still very rare. Photoswitches are freely diffusible molecules containing a photosensitive moiety which can alternate between two isomeric forms depending on light irradiation at specific wavelengths. These isomeric forms of the photoswitch possess different affinities or efficacies toward their biological target, such that their pharmacological activity can be turned on or off depending on the light wavelength used, thus providing temporal and spatial control. When photoswitches covalently tether to a native or engineered residue at the specific biological target, the resulting conformation would determine the corresponding pharmacological activity. One way the tethered photoswitch can be activated is by positioning the tether in such a way that the ligand moiety can reach its binding site in only one of the photoswitch conformations. Additional major advantages of the tethered photoswitches are high local concentration (the residue cannot diffuse away) and spatial restriction within the biological target. The ligand groups of photoswitches can possess diverse pharmacological activities, acting as agonists, inverse agonists, or antagonists at specific binding sites.The GABA_A receptor is formed by five subunits (usually two α, two β, and one γ or δ) arranged in pseudosymmetry around a central channel, in the following order (counterclockwise, viewed from the extracellular side): γ-β-α-β-α (2). Each interface is named after the subunits that form it, with “+” and “−” designated following the counterclockwise order (a model of the α1β3γ2 GABA_A receptor can be found in SI Appendix, Fig. S1). Each subunit consists of an extracellular domain, attached to a sequence of four transmembrane helices (TMs), with a large intracellular loop inserted between TM3 and TM4. Multiple anesthetic drugs that act through this receptor possess relatively low binding affinities; therefore, precise identification and characterization of their binding sites require the use of techniques like mutagenesis, substituted cysteine modification protection (SCAMP), and photolabeling with photoreactive anesthetic analogs (3). Structures of the GABA_A receptor with bound anesthetic drugs have recently been made available (4), but one unexplored way of obtaining valuable, functional information would be by using appropriately designed tethered photoswitches. In previous studies of GABA_A receptors, the photoswitches used have included diffusible propofol photoswitches (5, 6) and a tethered propofol photoswitch with a very long spacer between the tethering cysteine (located in the extracellular domain) and the propofol moiety (6). Though all three positively modulated GABA_A receptors, none could be used to define the propofol binding site.Multiple studies point to propofol binding cavities being located in the TM interfaces between GABA_A receptor subunits. The observation that specific mutations in TM2 or TM3 of GABA_A β subunits could dramatically decrease propofol potentiation of GABA responses, and even direct activation of the receptor (7–9) led to the development of the β3(N265M) knockin mouse, which showed either a greatly decreased or absent hypnotic effect of propofol, depending on the test used (10). More recent studies have focused on a more complete characterization of binding sites for propofol as well as other intravenous anesthetics. A photoreactive propofol analog labeled three amino acids in the β⁺α⁻ interface (β3M286, α1M236, and α1I239) and one in the α⁺β⁻ interface (β3M227) in α1β3 receptors. Using etomidate and R-mTFD-MPAB [R-5-allyl-1-methyl-5-(m-trifluoromethyldiazirinylphenyl)barbituric acid] to inhibit photolabeling established that propofol also binds to the β⁺β⁻ interface, suggesting that propofol shows little selectivity for either interface (11). Another study mutated photolabeled residues (α1M236, β3M227, and their homologs, all located in TM1) to tryptophan (causing steric occupancy of the pocket) and cysteine (to test propofol protection against cysteine-specific labeling) (12). SCAMP studies confirmed that propofol binds to the β⁺α⁻ and α⁺β⁻ interfaces, and also to the γ⁺β⁻ interface; there was no evidence of binding to the α⁺γ⁻ interface. A more recent study has expanded the analysis of residues at the β⁺α⁻ interface that line a putative propofol binding site (13) (SI Appendix, Fig. S1). And cryoelectron microscopy (cryo-EM) structures of α1β2γ2 GABA_A receptors bound to intravenous anesthetics and benzodiazepines have recently been published (4), consolidating the evidence toward a propofol binding site at the β⁺α⁻ interfaces.Our aim was to develop a β-subunit-tethered propofol photoswitch, as a tool to better study the mechanism of anesthesia through the GABA_A α1β3ɣ2 receptor, merging both structural and functional approaches. This tethered photoswitch (Fig. 1A) consists of propofol as the ligand group, linked to an azobenzene group (which is photosensitive and can change between cis and trans isomeric forms, Fig. 1B), and finally a tethering group (methanethiosulfonate, that spontaneously forms a covalent bond with the thiolate group of cysteines located in water-filled cavities). This photoswitch was abbreviated as MAP20 (methanethiosulfonate azobenzene propofol 2020). These three basic components of this tethered photoswitch are connected by short spacers, decreasing the range between tethering and target residues. We used β3 subunits in our study because the immobilizing and hypnotic effects of propofol are mostly mediated by β3-containing receptors (10).Open in a separate windowFig. 1.Tethered photoswitch. (A) Methanethiosulfonate azobenzene propofol 2020 (MAP20) consists of propofol (ligand group), an azobenzene moiety (photosensitive), and a tether (methanethiosulfonate). (B) The azobenzene moiety can change between cis and trans isomeric forms depending on the wavelength of the light irradiated.     

Interleukin-3 treatment of rhesus monkeys leads to increased production of histamine-releasing cells that express interleukin-3 receptors at high levels

To understand the hematopoietic and nonhematopoietic responses to interleukin-3 (IL-3), expression of cell-surface IL-3 receptors (IL-3R) was examined on bone marrow (BM) cells and peripheral blood (PB) cells of rhesus monkeys during the course of in vivo IL-3 treatment. Whereas IL-3R expression is low in untreated monkeys, IL-3 administration led to a gradual increase in both low- and high-affinity binding sites for IL-3. This increase reflected the total number of cells expressing IL- 3Rs, as detected by flow cytometry using biotinylated IL-3. Most of these IL-3R+ cells in both BM and PB could be characterized as basophilic granulocytes that contained high levels of histamine. In contrast to the effect on these differentiated cells, IL-3 administration did not significantly alter the low level IL-3R expression on immature, CD34+ cells. Further flow cytometric analysis using biotinylated growth factors showed that the IL-3R+ basophils also expressed receptors for granulocyte-macrophage colony-stimulating factor (GM-CSF), but not for IL-6 or Kit ligand. These findings indicated that the IL-3R+ cells included neither monocytes, which express GM-CSFRs and IL-6Rs abundantly, nor mast cells, which express c- kit. By combining flow cytometric and Scatchard data, it was calculated that the basophils contain as many as 1 to 2 x 10(3) high-affinity IL- 3Rs and 15 to 30 x 10(3) low-affinity sites. The finding that in vivo IL-3 treatment leads to the production of large numbers of cells that express high levels of IL-3R and are capable of producing histamine provides an explanation for the often severe allergic reactions that occur during prolonged IL-3 administration. It also indicates that IL- 3, in addition to its direct effects on hematopoietic cells, may also stimulate hematopoiesis through the release of secondary mediators such as histamine by IL-3-responsive mature cells.     

Support of human cord blood progenitor cells on human stromal cell lines transformed by SV40 large T antigen under the influence of an inducible (metallothionein) promoter

We describe the development of a human bone marrow (BM) culture system which allows study of the interaction of stromal cell lines (SCL) and highly purified hematopoietic progenitor cells. Normal BM stromal cells were electroporated with a plasmid containing the simian virus 40 (SV40) large T antigen (SV40 T Ag) under the control of a synthetic metallothionein promoter (MT4); this construct is designated MT4 SV40 T Ag. SCL in which the rate of proliferation could be controlled by altering the zinc (Zn) concentration were characterized, demonstrating that the SCL were heterogeneous with respect to G-CSF and GM-CSF production. Suppression of SCL proliferation on removal of Zn made it possible to use these lines in coculture with purified CD34+ progenitor cells from umbilical cord blood. The ability to control proliferation of SCL has allowed us to maintain the survival and expansion of colony- forming cells in culture for up to 2 months. These lines have enabled us to test for stromal cell characteristics at a clonal level and provided us with a tool to analyze the events leading to lineage commitment and hematopoietic differentiation, as demonstrated by suppression of hematopoiesis by an antibody directed against the c-kit molecule.     

Detection of the hemoglobin E mutation using the color complementation assay: application to complex genotyping

The color complementation assay (CCA) is a method of allele-specific DNA amplification by which competitive priming and extension of fluorescently labeled oligonucleotide primers determine the color of DNA amplification product. This diagnostic method precludes the need for radioisotopes, electrophoresis, and multiple high-stringency reaction conditions. The multiplicity of mutant globin genes present in Southeast Asians complicates clinical diagnosis and underscores the importance of DNA-based diagnostic methods. We have applied CCA to distinguish beta A and beta E alleles. Competing 15mer primers were a fluorescein-labeled complement to beta A and a rhodamine-labeled complement to beta E, identical except for their central nucleotides. A common unlabeled primer was used to amplify DNA product, the color of which was determined by the perfectly complementary primer. Color photography and spectrofluorometry, as well as a method of black-white photography that we developed to distinguish fluorescein- and rhodamine- labeled DNA, were used to record results. We applied CCA to define the complex genotype of a Thai woman with thalassemia intermedia, 96% HbE, and 4% HbF whose possible genotypes included several permutations of alpha-thalassemia, beta-thalassemia, and beta E genes. zeta-Globin gene mapping of DNA doubly digested with Bg/II and Asp 718 showed the -alpha 3.7/--SEA genotype, and CCA confirmed homozygous beta E/beta E. The CCA is useful for diagnosing the compound hemoglobin genotypes of Southeast Asians and could be applied also to prenatal diagnosis in this population.     

Ordered restriction endonuclease maps of yeast artificial chromosomes created by optical mapping on surfaces.

We have developed a surface mounting technology for the rapid construction of ordered restriction maps from individual DNA molecules. Optical restriction maps constructed from yeast artificial chromosome DNA molecules mounted on specially derivatized glass surfaces are accurate and reproducible, and the technology is amenable to automation. The mounting procedures described here should also be useful for fluorescence in situ hybridization studies. We believe these improvements to optical mapping will further stimulate the development of nonelectrophoretic approaches to genome analysis.     

Transient protein kinase C activation primes long-term depression and suppresses long-term potentiation of synaptic transmission in hippocampus.

Activity-dependent long-lasting plasticity in hippocampus and neocortex includes long-term potentiation (LTP) and long-term depression (LTD) of synaptic strength. Recent studies have confirmed theoretical predictions that the sensitivity of LTP- and LTD-inducing mechanisms is dynamically regulated by previous synaptic history. In particular, prior induction of either repeated short-term potentiations or LTP lowers the threshold for induction of LTD and raises the threshold for LTP. In the current study, transient activation of protein kinase C with phorbol 12,13-diacetate was able to substitute for synaptic activity in priming synapses to exhibit enhanced homosynaptic LTD and to suppress the induction of LTP at Schaffer collateral synapses in area CA1 of hippocampal slices. This priming lasted 30 min, but not 3 hr, following phorbol 12,13-diacetate bath application. These data suggest that a protein kinase C-sensitive phosphorylation site may be an activity-sensitive target mediating the rapid expression of LTP and LTD.