Publications by authors named "Alfonso D"

47 Publications

Boosting CO Electrochemical Reduction with Atomically Precise Surface Modification on Gold Nanoclusters.

Angew Chem Int Ed Engl 2021 Mar 12;60(12):6351-6356. Epub 2021 Feb 12.

Department of Chemistry, Carnegie Mellon University, Pittsburgh, PA, 15213, USA.

Thiolate-protected gold nanoclusters (NCs) are promising catalytic materials for the electrochemical CO reduction reaction (CO RR). In this work an atomic level modification of a Au NC is made by substituting two surface Au atoms with two Cd atoms, and it enhances the CO RR selectivity to 90-95 % at the applied potential between -0.5 to -0.9 V, which is doubled compared to that of the undoped Au . Additionally, the Cd-doped Au Cd exhibits the highest CO RR activity (2200 mA mg at -1.0 V vs. RHE) among the reported NCs. This synergetic effect between Au and Cd is remarkable. Density-functional theory calculations reveal that the exposure of a sulfur active site upon partial ligand removal provides an energetically feasible CO RR pathway. The thermodynamic energy barrier for CO formation is 0.74 eV lower on Au Cd than on Au . These results reveal that Cd doping can boost the CO RR performance of Au NCs by modifying the surface geometry and electronic structure, which further changes the intermediate binding energy. This work offers insights into the surface doping mechanism of the CO RR and bimetallic synergism.
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http://dx.doi.org/10.1002/anie.202016129DOI Listing
March 2021

Nasal mucosal brush biopsy for cat allergy.

Int Forum Allergy Rhinol 2021 Feb 13;11(2):195-197. Epub 2020 Oct 13.

Department of Otolaryngology-Head and Neck Surgery, Weill Cornell Medical College, New York, NY.

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http://dx.doi.org/10.1002/alr.22706DOI Listing
February 2021

Evaluation of two rapid immunochromatographic tests for diagnosis of brucellosis infection in cattle.

Open Vet J 2018 7;8(3):236-242. Epub 2018 Jul 7.

AIDS Research Laboratory (LISIDA), Mayabeque, Cuba.

Brucellosis is a serious infectious disease that causes significant economic losses in the livestock industry. Its early diagnosis allows an adequate disease control in cattle. DAVIH Laboratories designed a lateral flow immunochromatographic assay using protein A-colloidal gold as a detector reagent (LFIA-PA). The objective of this work was to compare the performance of this assay using protein G-colloidal gold (LFIA-PG) with its performance using protein A-colloidal gold as the detector reagent. The assays were carried out with 20 μL of serum and 130 μL of running buffer. Interpretation of bands was by visual inspection with the naked eye at 15- 20 minutes after sample application. The tests were evaluated with 449 samples of bovine serum (111 positive and 338 negative). The diagnostic sensitivity and specificity, the positive and negative predictive values, and the efficacy of both assays were calculated, and their concordance was estimated by calculating the (k) index. The estimated values of the parameters for LFIA-PG and LFPIA-PA were 100% and 95.2% of diagnostic sensitivity, 96.2% and 97.3% of diagnostic specificity, 89.5% and 92.3% for the positive predictive value, 100% and 98.5% for the negative predictive value, and 97.1% and 96.89% of efficacy, respectively. The concordance between both tests was very good ( = 0.95). It was shown the possibilities of developing a system with LFIA-PG capable of detecting antibodies against spp. The performance of the test makes possible its use as a screening method in the diagnosis of brucellosis.
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http://dx.doi.org/10.4314/ovj.v8i3.2DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6060728PMC
July 2018

Fructooligosaccharides production by Schedonorus arundinaceus sucrose:sucrose 1-fructosyltransferase constitutively expressed to high levels in Pichia pastoris.

J Biotechnol 2018 Jan 12;266:59-71. Epub 2017 Dec 12.

Grupo Tecnología de Enzimas, Dirección de Investigaciones Agropecuarias, Centro de Ingeniería Genética y Biotecnología (CIGB), Ave 31 entre 158 y 190, Apartado Postal 6162, Habana, 10600, Cuba.

The non-saccharolytic yeast Pichia pastoris was engineered to express constitutively the mature region of sucrose:sucrose 1-fructosyltransferase (1-SST, EC 2.4.1.99) from Tall fescue (Schedonorus arundinaceus). The increase of the transgene dosage from one to nine copies enhanced 7.9-fold the recombinant enzyme (Sa1-SSTrec) yield without causing cell toxicity. Secretion driven by the Saccharomyces cerevisiae α-factor signal peptide resulted in periplasmic retention (38%) and extracellular release (62%) of Sa1-SSTrec to an overall activity of 102.1 U/ml when biomass reached (106 g/l, dry weight) in fed-batch fermentation using cane sugar for cell growth. The volumetric productivity of the nine-copy clone PGFT6x-308 at the end of fermentation (72 h) was 1422.2 U/l/h. Sa1-SSTrec purified from the culture supernatant was a monomeric glycoprotein optimally active at pH 5.0-6.0 and 45-50 °C. The removal of N-linked oligosaccharides by Endo Hf treatment decreased the enzyme stability but had no effect on the substrate and product specificities. Sa1-SSTrec converted sucrose (600 g/l) into 1-kestose (GF) and nystose (GF) in a ratio 9:1 with their sum representing 55-60% (w/w) of the total carbohydrates in the reaction mixture. Variations in the sucrose (100-800 g/l) or enzyme (1.5-15 units per gram of substrate) concentrations kept unaltered the product profile. Sa1-SSTrec is an attractive candidate enzyme for the industrial production of short-chain fructooligosaccharides, most particularly 1-kestose.
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http://dx.doi.org/10.1016/j.jbiotec.2017.12.008DOI Listing
January 2018

Normal Intracranial Translucency Values During the First Trimester of Gestation in a Latin American Population.

J Ultrasound Med 2016 Oct 31;35(10):2231-6. Epub 2016 Aug 31.

Department of Obstetrics and Gynecology, Division of Maternal-Fetal Medicine, Colsubsidio Maternal and Children's Hospital, Bogota, Colombia.

Objectives: The purpose of this study was to establish intracranial translucency reference values in healthy fetuses from a Latin American population.

Methods: This work was a cross-sectional retrospective correlational study. A review of sonographic reports from women between gestational ages of 11 weeks and 13 weeks 6 days at 2 health institutes in Bogota, Colombia, whose fetuses had a crown-rump length of 45 to 84 mm was conducted between January 1, 2010, and December 31, 2012. Women with multiple fetuses or with a deceased fetus were excluded.

Results: Data corresponding to 1520 obstetric sonographic examinations were included in the statistical analysis. The crown-rump length was between 45 and 84 mm, with a median of 65 mm (interquartile range, 58-73 mm). The median intracranial translucency was 1.7 mm (interquartile range, 1.4-2.2 mm). Different percentiles (1st, 5th, 10th, 25th, 50th, 75th, 90th, 95th, and 99th) were established for each crown-rump length value. A correlation between crown-rump length and intracranial translucency was found, which seemed to be linear. The intracranial translucency value was not significantly correlated with the frontomaxillary angle but was correlated with nuchal translucency, nasal bone length, and metopic suture length.

Conclusions: We present normal intracranial translucency values in the first trimester of single gestations with live fetuses in a Latin American population. These values are similar to those described in other populations. The intracranial translucency value was linearly correlated with crown-rump length in fetuses between gestational ages of 11 weeks and 13 weeks 6 days, which is consistent with previous publications, although these data cannot be interpreted independently.
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http://dx.doi.org/10.7863/ultra.15.12013DOI Listing
October 2016

Active sites of ligand-protected Au25 nanoparticle catalysts for CO2 electroreduction to CO.

J Chem Phys 2016 May;144(18):184705

National Energy Technology Laboratory, U. S. Department of Energy, Pittsburgh, Pennsylvania 15236, USA.

Recent experimental studies have reported the electrochemical reduction of carbon dioxide (CO2) into CO at atomically precise negatively charged Au25 (-) nanoclusters. The studies showed CO2 conversion at remarkably low overpotentials, but the exact mechanisms and nature of the active sites remain unclear. We used first-principles density functional theory and continuum solvation models to examine the role of the cluster during electrochemical CO2 reduction and analyze the free energies of proposed intermediate species. Contrary to previous assumptions, our results show that the fully ligand protected cluster is not an active CO2 reduction catalyst because formation of the crucial carboxyl intermediate required very high electrochemical potentials. Instead, our calculations suggest that the reduction process likely occurs on a dethiolated gold site, and adsorbed carboxyl intermediate formation was significantly stabilized at dethiolated gold sites. These findings point to the crucial role of exposed metal sites during electrochemical CO2 reduction at gold nanocluster catalysts.
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http://dx.doi.org/10.1063/1.4948792DOI Listing
May 2016

Kinetic Monte Carlo simulation of CO adsorption on sulfur-covered Pd(100).

J Phys Chem A 2014 Sep 12;118(35):7306-13. Epub 2014 Feb 12.

National Energy Technology Laboratory, U.S. Department of Energy , Pittsburgh, Pennsylvania 15236, United States.

The use of atomistic Kinetic Monte Carlo method was explored to examine the influence of sulfur poisoning on CO adsorption on Pd(100) surface. The model explicitly incorporates key elementary processes such as CO adsorption and CO desorption including diffusion of surface CO and S species. Relevant energetic and kinetic parameters were derived using information calculated from density functional theory as a starting point. Kinetic Monte Carlo simulation was performed to determine relevant observables such as CO saturation coverage as a function of amount of preadsorbed sulfur and to predict temperature programmed desorption spectra.
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http://dx.doi.org/10.1021/jp4115817DOI Listing
September 2014

Synthesis of open-shell, bimetallic Mn/Fe trinuclear clusters.

J Am Chem Soc 2013 Sep 11;135(38):14448-58. Epub 2013 Sep 11.

Department of Chemistry and Chemical Biology, Harvard University , 12 Oxford Street, Cambridge, Massachusetts 02138, United States.

Concomitant deprotonation and metalation of hexadentate ligand platform (tbs)LH6 ((tbs)LH6 = 1,3,5-C6H9(NHC6H4-o-NHSiMe2(t)Bu)3) with divalent transition metal starting materials Fe2(Mes)4 (Mes = mesityl) or Mn3(Mes)6 in the presence of tetrahydrofuran (THF) resulted in isolation of homotrinuclear complexes ((tbs)L)Fe3(THF) and ((tbs)L)Mn3(THF), respectively. In the absence of coordinating solvent (THF), the deprotonation and metalation exclusively afforded dinuclear complexes of the type ((tbs)LH2)M2 (M = Fe or Mn). The resulting dinuclear species were utilized as synthons to prepare bimetallic trinuclear clusters. Treatment of ((tbs)LH2)Fe2 complex with divalent Mn source (Mn2(N(SiMe3)2)4) afforded the bimetallic complex ((tbs)L)Fe2Mn(THF), which established the ability of hexamine ligand (tbs)LH6 to support mixed metal clusters. The substitutional homogeneity of ((tbs)L)Fe2Mn(THF) was determined by (1)H NMR, (57)Fe Mössbauer, and X-ray fluorescence. Anomalous scattering measurements were critical for the unambiguous assignment of the trinuclear core composition. Heating a solution of ((tbs)LH2)Mn2 with a stoichiometric amount of Fe2(Mes)4 (0.5 mol equiv) affords a mixture of both ((tbs)L)Mn2Fe(THF) and ((tbs)L)Fe2Mn(THF) as a result of the thermodynamic preference for heavier metal substitution within the hexa-anilido ligand framework. These results demonstrate for the first time the assembly of mixed metal cluster synthesis in an unbiased ligand platform.
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http://dx.doi.org/10.1021/ja408003dDOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3822335PMC
September 2013

Capsular contracture rate in a low-risk population after primary augmentation mammaplasty.

Aesthet Surg J 2013 May;33(4):516-21

Michigan State University College of Human Medicine, Grand Rapids, Michigan, USA.

Background: The safety of augmentation mammaplasty has increased dramatically in the past 20 years. Capsular contracture (CC) is the most commonly reported complication of augmentation mammaplasty.

Objectives: The authors report the incidence of CC in a low-risk patient population after primary augmentation.

Methods: The authors retrospectively reviewed the charts of 856 consecutive patients who underwent primary augmentation mammaplasty between 1999 and 2009. This series did not include patients who underwent breast augmentation-mastopexy, secondary augmentation, revision, and/or reconstruction. Data points included demographics, functional and aesthetic outcomes, complications, and revision rate/type.

Results: The overall incidence of CC in 856 patients was 2.8%. Average follow-up time was 14.9 months. Antibiotic irrigation decreased CC rates from 3.9% to 0.4% (P = .004). Tobacco users had higher rates of contracture than nonsmokers (5.5% vs 1.9%; P = .036). Saline implants had a higher CC rate than silicone gel (4.3% vs 1.3%; P = .032). Using multivariate logistic regression, CC was 7.89 times more likely in saline implants than in silicone gel (P = .027, 95% confidence interval, 1.26-49.00).

Conclusions: Based on our findings, it is apparent that the early CC rate in primary augmentation can be less than 1%. To avoid CC, we advocate an inframmamary approach, submuscular implant placement, and antibiotic irrigation of the breast pocket.

Level Of Evidence: 3.
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http://dx.doi.org/10.1177/1090820X13484465DOI Listing
May 2013

Photomediated Oxidation of Atomically Precise Au25(SC2H4Ph)18(-) Nanoclusters.

J Phys Chem Lett 2013 Jan 26;4(1):195-202. Epub 2012 Dec 26.

§Department of Chemistry, Carnegie Mellon University, Pittsburgh, Pennsylvania 15213, United States.

The anionic charge of atomically precise Au25(SC2H4Ph)18(-) nanoclusters (abbreviated as Au25(-)) is thought to facilitate the adsorption and activation of molecular species. We used optical spectroscopy, nonaqueous electrochemistry, and density functional theory to study the interaction between Au25(-) and O2. Surprisingly, the oxidation of Au25(-) by O2 was not a spontaneous process. Rather, Au25(-)-O2 charge transfer was found to be a photomediated process dependent on the relative energies of the Au25(-) LUMO and the O2 electron-accepting level. Photomediated charge transfer was not restricted to one particular electron accepting molecule or solvent system, and this phenomenon likely extends to other Au25(-)-adsorbate systems with appropriate electron donor-acceptor energy levels. These findings underscore the significant and sometimes overlooked way that photophysical processes can influence the chemistry of ligand-protected clusters. In a broader sense, the identification of photochemical pathways may help develop new cluster-adsorbate models and expand the range of catalytic reactions available to these materials.
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http://dx.doi.org/10.1021/jz302056qDOI Listing
January 2013

Vertical reduction mammaplasty utilizing the superomedial pedicle: is it really for everyone?

Aesthet Surg J 2012 Aug;32(6):718-25

Michigan State University's College of Human Medicine, Grand Rapids, USA.

Background: Classically, the vertical-style reduction mammaplasty utilizing a superomedial pedicle has been limited to smaller reductions secondary to concerns for poor wound healing and nipple necrosis.

Objectives: The authors reviewed a large cohort of patients who underwent a vertical-style superomedial pedicle reduction mammaplasty in an attempt to demonstrate its safety and efficacy in treating symptomatic macromastia.

Methods: A retrospective review was performed of 290 patients (558 breasts) who underwent a vertical-style superomedial pedicle reduction mammaplasty. All procedures were conducted by one of 4 plastic surgeons over 6 years (JDR, MAA, DLV, DRA).

Results: The average resection weight was 551.7 g (range, 176-1827 g), with 4.6% of resections greater than 1000 g. A majority of patients (55.2%) concomitantly underwent liposuction of the breast. The total complication rate was 22.7%, with superficial dehiscence (8.8%) and hypertrophic scarring (8.8%) comprising the majority. Nipple sensory changes occurred in 1.6% of breasts, with no episodes of nipple necrosis. The revision rate was 2.2%. Patients with complications had significantly higher resection volumes and nipple-to-fold distances (P = .014 and .010, respectively).

Conclusions: The vertical-style superomedial pedicle reduction mammaplasty is safe and effective for a wide range of symptomatic macromastia. The nipple-areola complex can be safely transposed, even in patients with larger degrees of macromastia, with no episodes of nipple necrosis. The adjunctive use of liposuction should be considered safe. Last, revision rates were low, correlating with a high level of patient satisfaction.
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http://dx.doi.org/10.1177/1090820X12452733DOI Listing
August 2012

Spectroscopic measurement of cartilage thickness in arthroscopy: ex vivo validation in human knee condyles.

Arthroscopy 2012 Oct 21;28(10):1513-23. Epub 2012 Jun 21.

Department of Biomedical Engineering, Linköping University, Linköping, Sweden.

Purpose: To evaluate the accuracy of articular cartilage thickness measurement when implementing a new technology based on spectroscopic measurement into an arthroscopic camera.

Methods: Cartilage thickness was studied by ex vivo arthroscopy at a number of sites (N = 113) in human knee joint osteoarthritic femoral condyles and tibial plateaus, removed from 7 patients undergoing total knee replacement. The arthroscopic image spectral data at each site were used to estimate cartilage thickness. Arthroscopically derived thickness values were compared with reference cartilage thickness as measured by 3 different methods: needle penetration, spiral computed tomography scanning, and geometric measurement after sample slicing.

Results: The lowest mean error (0.28 to 0.30 mm) in the regression between arthroscopic and reference cartilage thickness was seen for reference cartilage thickness less than 1.5 mm. Corresponding values for cartilage thickness less than 2.0 and 2.5 mm were 0.32 to 0.40 mm and 0.37 to 0.47 mm, respectively. Cartilage thickness images--created by pixel-by-pixel regression model calculations applied to the arthroscopic images--were derived to demonstrate the clinical use of a camera implementation.

Conclusions: On the basis of this investigation on osteoarthritic material, when one is implementing the spectroscopic method for estimating cartilage thickness into an arthroscopic camera, errors in the range of 0.28 to 0.30 mm are expected. This implementation does not, however, influence the fact that the spectral method performs less well in the cartilage thickness region from 1.5 to 2.5 mm and cannot assess cartilage thicker than 2.5 mm.

Clinical Relevance: Imaging cartilage thickness directly in the arthroscopic camera video stream could serve as an interesting image tool for in vivo cartilage quality assessment, in connection with cartilage diagnosis, repair, and follow-up.
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http://dx.doi.org/10.1016/j.arthro.2012.03.009DOI Listing
October 2012

Experimental and computational investigation of Au25 clusters and CO2: a unique interaction and enhanced electrocatalytic activity.

J Am Chem Soc 2012 Jun 6;134(24):10237-43. Epub 2012 Jun 6.

National Energy Technology Laboratory, United States Department of Energy, Pittsburgh, Pennsylvania 15236, USA.

Atomically precise, inherently charged Au(25) clusters are an exciting prospect for promoting catalytically challenging reactions, and we have studied the interaction between CO(2) and Au(25). Experimental results indicate a reversible Au(25)-CO(2) interaction that produced spectroscopic and electrochemical changes similar to those seen with cluster oxidation. Density functional theory (DFT) modeling indicates these changes stem from a CO(2)-induced redistribution of charge within the cluster. Identification of this spontaneous coupling led to the application of Au(25) as a catalyst for the electrochemical reduction of CO(2) in aqueous media. Au(25) promoted the CO(2) → CO reaction within 90 mV of the formal potential (thermodynamic limit), representing an approximate 200-300 mV improvement over larger Au nanoparticles and bulk Au. Peak CO(2) conversion occurred at -1 V (vs RHE) with approximately 100% efficiency and a rate 7-700 times higher than that for larger Au catalysts and 10-100 times higher than those for current state-of-the-art processes.
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http://dx.doi.org/10.1021/ja303259qDOI Listing
June 2012

Hand function in children with an upper brachial plexus birth injury: results of the nine-hole peg test.

Dev Med Child Neurol 2012 Feb 1;54(2):166-9. Epub 2011 Dec 1.

Department of Orthopedic Surgery, NYU Hospital for Joint Diseases, New York, NY, USA.

Aim: The aim of this study was to evaluate hand function in children with Erb upper brachial plexus palsy.

Method: Hand function was evaluated in 25 children (eight males; 17 females) with a diagnosed upper (C5/C6) brachial plexus birth injury. Of these children, 22 had undergone primary nerve reconstruction and 13 of the 25 had undergone simultaneous and/or secondary shoulder procedures. Hand function was evaluated using the nine-hole peg test at a mean age of 9 years (SD 2y 2mo), and compared with the contralateral, uninvolved hand. Results were compared with age- and sex-matched population norms, and correlated with shoulder outcomes using the Gilbert and Miami scores.

Results: Although shoulder function was graded as good or excellent in 24 of 25 children, hand function as measured by the nine-hole peg test was significantly altered in the involved hand in 80% (p=0.008). On average the participants took 18.8% longer to complete the task with the involved hand; this was significantly different from the expected difference of 7.2% (p=0.008).

Interpretation: Hand function is impaired in individuals with upper brachial plexus birth injury. These results suggest that from the initiation of treatment in this population, attention should be paid to recognizing and focusing therapy on subtle limitations of hand function.
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http://dx.doi.org/10.1111/j.1469-8749.2011.04120.xDOI Listing
February 2012

Causes of neonatal brachial plexus palsy.

Authors:
Daniel T Alfonso

Bull NYU Hosp Jt Dis 2011 ;69(1):11-6

Department of Orthopaedic Surgery, NYU Hospital for Joint Diseases, NYU Langone Medical Center, New York, NY, USA.

The causes of brachial plexus palsy in neonates should be classified according to their most salient associated feature. The causes of brachial plexus palsy are obstetrical brachial plexus palsy, familial congenital brachial plexus palsy, maternal uterine malformation, congenital varicella syndrome, osteomyelitis involving the proximal head of the humerus or cervical vertebral bodies, exostosis of the first rib, tumors and hemangioma in the region of the brachial plexus, and intrauterine maladaptation. Kaiser Wilhelm syndrome, neonatal brachial plexus palsy due to placental insufficiency, is probably not a cause of brachial plexus palsy. Obstetrical brachial plexus palsy, the most common alleged cause of neonatal brachial plexus palsy, occurs when the forces generated during labor stretch the brachial plexus beyond its resistance. The probability of obstetrical brachial plexus palsy is directly proportional to the magnitude, acceleration, and cosine of the angle formed by the direction of the vector of the stretching force and the axis of the most vulnerable brachial plexus bundle, and inversely proportional to the resistance of the must vulnerable brachial plexus bundle and of the shoulder girdle muscles, joints, and bones. Since in most nonsurgical cases neither the contribution of each of these factors to the production of the obstetrical brachial plexus palsy nor the proportion of traction and propulsion contributing to the stretch force is known, we concur with prior reports that the term of obstetrical brachial plexus palsy should be substituted by the more inclusive term of birth-related brachial plexus palsy.
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June 2011

Cortical dysplasia and obstetrical brachial plexus palsy.

J Child Neurol 2008 Dec;23(12):1477-80

Brachial Plexus Center, Department of Neurology, Miami Children's Hospital, Miami, Florida 33155-4079, USA.

We report 2 patients with obstetrical brachial plexus palsy, ipsilateral leg weakness, and contralateral motor cortical dysplasia. To our knowledge, this is the first description of such an association. In both cases, the diagnosis of obstetrical brachial plexus palsy was established clinically shortly after birth and later confirmed neurophysiologically. Motor cortex dysplasia was diagnosed by magnetic resonance imaging (MRI). The association of obstetrical brachial plexus palsy and contralateral motor cortex dysplasia, a condition known to produce congenital hemiparesis, raises the possibility that the cortical dysplasia was a predisposing factor for obstetrical brachial plexus palsy in these cases.
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http://dx.doi.org/10.1177/0883073808319315DOI Listing
December 2008

Resolution of brachial plexus palsy due to hemangioma after intravenous corticosteroid therapy.

J Child Neurol 2008 Aug;23(8):956-8

Brachial Plexus Center, Miami Children's Hospital, Department of Neurology, Miami Children's Hospital, Miami, Florida, USA.

The authors report a 7-day-old girl born with a hemangioma involving the right side of the scalp and neck who developed ipsilateral brachial plexus palsy at 5 days of age. Imaging studies confirmed the presence of a cavernous hemangioma in the vicinity of the brachial plexus. She was treated with intravenous corticosteroids and her palsy resolved in 5 days. Only 1 prior case of hemangioma producing brachial plexus palsy has been reported; this patient was not treated with corticosteroids and had a partial recovery. The authors believe that the quick recovery after initiating systemic steroids was due to relief of nerve compression (neuropraxia) resulting from shrinkage of the cavernous hemangioma. The purpose of this article is to describe an uncommon cause of neonatal brachial plexus palsy and to report the effectiveness of early intravenous corticosteroid treatment in a patient with brachial plexus palsy due to a cavernous hemangioma.
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http://dx.doi.org/10.1177/0883073808315346DOI Listing
August 2008

Total hip arthroplasty in the underweight.

J Arthroplasty 2008 Oct 4;23(7):956-9. Epub 2008 Mar 4.

Department of Orthopaedic Surgery, Musculoskeletal Research Center, NYU-Hospital for Joint Diseases, New York, New York, USA.

The outcomes of 20 patients diagnosed with osteoarthritis or rheumatoid arthritis with body mass index less than 18.5 (considered underweight) who received total hip arthroplasty at a single institution were reviewed. Surgical complications in the first 30 days after surgery included 1 prolonged surgical site drainage and 3 posterior dislocations. Two patients experienced medical complications that included hematemesis, confusion, aspiration pneumonia, and death. Sixty-five percent of the patients received at least one blood transfusion. Harris hip scores improved from 35 to 81 (P < .05) at an average of 6.1 years (2-10.1 years) of follow-up. Total hip arthroplasty is effective in patients who are underweight; however, they appear to be at an increased risk of dislocation and blood transfusion.
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http://dx.doi.org/10.1016/j.arth.2007.09.008DOI Listing
October 2008

Mastopexy using the short scar periareolar inferior pedicle reduction technique.

Plast Reconstr Surg 2008 May;121(5):1533-1539

Grand Rapids, Mich. From the Center for Breast and Body Contouring.

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http://dx.doi.org/10.1097/PRS.0b013e31816c3b0bDOI Listing
May 2008

Orthopedic manifestations and management of psoriatic arthritis.

Am J Orthop (Belle Mead NJ) 2008 Mar;37(3):138-47

Department of Orthopaedic Surgery, New York University Hospital for Joint Diseases, New York, New York, USA.

Psoriatic arthritis is a complex, chronic inflammatory disease with both skin and joint involvement. Clinical presentation varies considerably among patients and during the course of the disease. Assessment of patients for psoriatic arthritis requires careful attention to patient history, a focused physical examination, and inspection for characteristic radiographic changes. Although this disease was once thought to be a rare and mild form of arthritis, recent studies have shown that patients with psoriatic arthritis may develop significant disability, with up to 20% of cases demonstrating a rapidly progressive, debilitating clinical course. Orthopedic manifestations of the disease can be severe and can cause significant physical disability. Although surgical intervention for psoriatic arthritis is relatively uncommon, having an understanding of the assessment, available treatment options, and surgical considerations allows for improved outcome in the management of this complex patient population.
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March 2008

Total hip and knee arthroplasty in nonagenarians.

J Arthroplasty 2007 Sep;22(6):807-11

Department of Orthopaedic Surgery, Musculoskeletal Research Center, NYU Hospital for Joint Diseases, New York, NY 10003, USA.

Among 25 patients of mean age 91.5 years (range, 90-96 years) who received a total hip or knee arthroplasty at the authors' institution, 8% experienced surgical complications, 56% experienced at least 1 medical complication, and 80% received perioperative blood transfusions. At a mean follow-up of 4.1 years, patients were experiencing pain reduction and somewhat higher functional capacity and had slightly better survival characteristics than age-matched controls. Total hip and knee arthroplasty patients in this cohort should be told that they have a higher likelihood of experiencing perioperative medical complications and of receiving a blood transfusion than younger individuals; at the same time, they can expect pain relief as well as equal or better survival than their age-matched peers.
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http://dx.doi.org/10.1016/j.arth.2006.10.016DOI Listing
September 2007

IFI16 inhibits tumorigenicity and cell proliferation of bone and cartilage tumor cells.

Front Biosci 2007 Sep 1;12:4855-63. Epub 2007 Sep 1.

Department of Orthopaedic Surgery, New York University School of Medicine, New York, New York 10003, USA.

IFI16 is a member of the interferon-inducible p200-protein family, capable of modulating cell proliferation, and cellular senescence. In this study, these effects of IFI16 were studied in tumor cells derived from bone and cartilage. The level of IFI16 was markedly lower in human osteosarcomas as compared with its level in normal bone. Overexpression of functional IFI16 in human osteosarcoma and chondrosarcoma cell lines markedly inhibited colony formation, and significantly inhibited cell growth, an effect that could be reversed by introduction of gene specific siRNA into tumor cells. These inhibitory effects of IFI16 were associated with upregulation of p21 and inhibition of cyclin E, cyclin D1, c-Myc and Ras. In addition, ectopic expression of IFI16 in tumor cells increased senescence-associated beta-galactosidase and induced a senescence-like phenotype. In view of such effects, IFI16 might be a suitable target for therapeutic intervention in osteosarcoma and chondrosarcoma.
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http://dx.doi.org/10.2741/2433DOI Listing
September 2007

Transcriptional activation of cartilage oligomeric matrix protein by Sox9, Sox5, and Sox6 transcription factors and CBP/p300 coactivators.

Front Biosci 2007 May 1;12:3899-910. Epub 2007 May 1.

Department of Orthopaedic Surgery, NYU Hospital for Joint Diseases, New York, NY 10003, USA.

The gene for cartilage oligomeric matrix protein (COMP) encodes a noncollagenous matrix protein that is expressed predominantly in cartilage. COMP gene expression is deficient in the Sox9-null mouse, but the molecular mechanism remains unknown. We have previously delineated a 30-bp negative regulatory element (NRE) and a 51-bp positive regulatory element (PRE) in the regulatory region of the COMP gene. Subsequently we isolated LRF transcription repressor as an NRE-binding protein and established that LRF inhibits COMP gene expression via recruiting histone deacetylase 1 (HDAC1) to the COMP promoter. In this study we demonstrated that Sox9, an essential transcription factor of chondrogenesis, binds to the COMP promoter at the PRE in which 13 nucleotides (TGTTTACCTTGTG) are required for the binding of Sox9. Sox9 activates COMP gene expression and this activation is PRE-dependent. Sox9 is required for COMP gene expression during chondrogenesis, since repression of Sox9 expression using the small interfering RNA approach inhibited COMP gene expression. In addition, activation of COMP gene expression by Sox9 requires the participation of transcription factors Sox5 and Sox6 as well as the coactivators CBP and p300 histone acetylase. It appears that there exists a balance between LRF repressor and Sox9 activator in the control of COMP gene, since transactivation of COMP gene by Sox9 was abolished by the coexpression of LRF, and excess Sox9 overcame the LRF-mediated inhibition. This study provides the first evidence that Sox9 directly associates with COMP gene promoter and that mediation of COMP gene activation by Sox9 involves Sox5, Sox6, CBP, and p300 coactivators.
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http://dx.doi.org/10.2741/2359DOI Listing
May 2007

The effect of concurrent fibular fracture on the fixation of distal tibia fractures: a laboratory comparison of intramedullary nails with locked plates.

J Orthop Trauma 2007 Mar;21(3):172-7

Department of Orthopedic Surgery, NYU-Hospital for Joint Diseases, New York, NY 10016, USA.

Objective: To compare the fixation stability of intramedullary nails to that of locked plates for the treatment of distal metaphyseal tibia and fibula fractures.

Methods: A simulated, distal metaphyseal tibia fracture was created in 8 pairs of cadaveric tibia-fibula specimens. One of each pair was treated using an intramedullary nail (Trigen IM Nail System; SN Richards, Memphis, TN) and the other with a locked plate (Peri-Loc Periarticular Locked Plating System; SN Richards). Each specimen was vertically loaded to 250 N in central, anterior, posterior, medial, and lateral locations; loaded to 250 N in cantilever bending in anterior to posterior and posterior to anterior directions; and loaded to 250 N mm in torsion. Load-displacement curves were generated to determine the construct stiffness for each loading scenario, with comparisons made between the 2 treatment groups. Each specimen was then cyclically loaded with 750 N vertical loads applied for 10, 100, 1000, and 10,000 cycles. Measurements of fracture displacements were made and compared between treatment groups. A fibular osteotomy was then created in each specimen at the same level as the tibia fracture to simulate a same-level tibia-fibular fracture. Torsional stiffness assessment and cyclic vertical loading for 10, 100, 1000, and 10,000 cycles were repeated and fracture displacement measurements were again obtained.

Results: The locked plate construct was stiffer than the intramedullary nail construct for central, anterior, and posterior loading scenarios (P < 0.005, P < 0.03, and P < 0.02, respectively). The intramedullary nail construct was stiffer than the locked plate construct for both anterior to posterior and posterior to anterior cantilever bending (P < 0.03 and P < 0.02, respectively). No statistically significant difference in stiffness was noted between treatment groups for medial and lateral vertical loading or for torsional loading (P = 0.09, P = 0.32, and P = 0.84, respectively). There was no significant difference between treatment groups with respect to fracture displacement after cyclic vertical loading. After creation of the fibular osteotomy fracture, construct displacements after 1000 and 10,000 cycles significantly increased and torsional stiffness significantly decreased for both treatment groups. The locked plate constructs had significantly less displacement after cyclic loading of 1000 and 10,000 than the locked nail constructs (P < 0.001 and P < 0.0001, respectively). Locked plate constructs were stiffer in torsion after osteotomy than the intramedullary nail constructs (P < 0.05).

Conclusion: This study demonstrated that, in the treatment of distal metaphyseal tibia fractures, locked plates provided more stable fixation than intramedullary nails in vertical loading but were less effective in cantilever bending. An intact fibula in the presence of a distal tibia fracture improved the fracture fixation stability for both treatment methods. In fracture patterns in which the fibula cannot be effectively stabilized, locked plates offer improved mechanical stability when compared with locked intramedullary nails.
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http://dx.doi.org/10.1097/BOT.0b013e3180332dd2DOI Listing
March 2007

Nonsurgical complications after total hip and knee arthroplasty.

Am J Orthop (Belle Mead NJ) 2006 Nov;35(11):503-10

New York University School of Medicine-Hospital for Joint Diseases, New York, New York, USA.

Postoperative medical complications after total hip arthroplasty (THA) and total knee arthroplasty (TKA) may occur in patients of any age. However, percentage of adverse events increases with increasing patient age and can cause significant morbidity and even mortality. It is important that the orthopedist identify risk factors and symptoms and be knowledgeable in the treatment of nonsurgical postoperative complications. Nonsurgical complications after THA and TKA include pulmonary embolism, fat embolism syndrome, pneumonia, myocardial infarction, postoperative delirium, cerebrovascular accident, urinary retention, urinary tract infections, and deep vein thrombosis.
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November 2006

Fetal deformations: a risk factor for obstetrical brachial plexus palsy?

Pediatr Neurol 2006 Oct;35(4):246-9

Brachial Plexus Center, Department of Neurology, Miami Children's Hospital, Miami, Florida 33155, USA.

The purpose of this report is to discuss the association of brachial plexus palsy and congenital deformations. We reviewed all charts of patients less than 1 year of age with obstetrical brachial plexus palsy evaluated by one of the authors (IA) between January 1998 and October 2005 at Miami Children's Hospital Brachial Plexus Center. Of 158 patients with obstetrical brachial plexus palsy, 7 had deformations (4.4%). Deformations were present in 32% of patients delivered by cesarean section, but in only 2% of patients delivered vaginally. The deformations were ipsilateral, involving the chest in two patients, distal arms in two patients, proximal arm in one patient, ear in one patient, and the leg in one patient. All patients with deformations had unilateral Erb's palsies. None had a history of maternal uterine malformation. Two presumptive mechanisms of injury, one causing the deformation (compressive forces) and one causing brachial plexus palsy at the time of delivery (traction forces), were present in all cases. The higher incidence of deformation in patients with obstetrical brachial plexus palsy born by cesarean sections and the presence of two presumptive mechanisms in all of the cases presented here raises the possibility that fetal deformations are a risk factor for obstetrical brachial plexus palsy.
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http://dx.doi.org/10.1016/j.pediatrneurol.2006.03.011DOI Listing
October 2006

[Pulmonary ventricle bypass operations].

Rev Port Cir Cardiotorac Vasc 2006 Apr-Jun;13(2):69-74

Unidade de Cirurgia Cardíaca Pediátrica, Serviço de Cirurgia Cardiotorácica do Hospital de Santa Marta, Lisboa.

Unlabelled: Cavopulmonary connections have been extensively used in the palliation of complex forms of congenital heart disease requiring some form of right heart bypass. We examine the mid term outcomes of pulmonary ventricle bypass operations in a single institution and performed by the same surgical team.

Population: Between March 1999 and April 2006, 62 patients underwent pulmonary ventricle bypass operations: bidirectional cavopulmonary anastomosis (Glenn procedure), total cavopulmonary connections (Fontan procedure) and one and a half ventricle correction in two cases. Age at operation averaged three years (range: 0.42-25 years) for the Glenn procedure and seven years (range: 3-14 years) for the Fontan procedure. There were 36 male patients (58%) and 26 female patients (42%). The most common indication for surgery was the single ventricle defect, present in 66% of patients. Associated lesions included: transposition of the great arteries in 16 patients (35.6%), bilateral superior vena cava in four patients (8.9%), situs ambigus in five patients (11%), situs inversus in another patient (2.2%), Ebstein disease in one patient (2.2) and coronary fistula in another patient (2.2%). Sub-aortic stenosis was present in one patient (2.2%). Palliative surgery was performed in all, but three patients (5%), before the Fontan procedure.

Results: Thirty two patients underwent bidirectional cavopulmonary anastomosis and thirty patients underwent cavopulmonary connections, total or 2nd stage. Mean cardiopulmonary bypass times were 50.6+/-21.9 minutes for the Glenn procedure and 88.5+/-26.3 minutes for the Fontan procedure. There was no intra-operative mortality, but two patients (3.2% (died in the first month after surgery; one due to failure of the Glenn circuit and sepsis and the other due to a low cardiac output syndrome and multi-organ dysfunction. Mean ventilation time was 5.2+/-1.7 hours for the Glenn operation and 6.2+/-3.2 hours for the Fontan operation. The mean length of stay in ICU was 3.4+/-2.8 days for patients undergoing the Glenn operation and 4.6+/-3.1 days for patients undergoing the Fontan operation and the mean length of hospital stay was 10.6+/-5.8 days for the Glenn operation and 19.1+/-12.6 days for the Fontan operation respectively. The mean follow up time was 4+/-2.1 years (minimum 0 years and maximum seven years), most patients being in NYHA class I. Epicardiac pacemakers were implanted in three patients due to arrhythmias. Two re-operations (6.7%) were needed, both in the same patient, after the Fontan procedure, this patient eventually died a few years after surgery.

Conclusions: The immediate and mid term outcomes of pulmonary ventricle bypass operations can have excellent results. From our point of view there has been an improvement, namely in the use of the extracardiac conduit technique in the 2nd stage of the Fontan operation.
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November 2009

Concomitant ipsilateral femoral neck and femoral shaft fracture nonunions: a report of three cases and a review of the literature.

Iowa Orthop J 2006 ;26:112-8

NYU/Hospital for Joint Diseases, 301 East 17th Street, New York, NY 10003, USA.

Ipsilateral femoral neck and femoral shaft fractures are rarely reported in the literature and represent a diagnostic and treatment challenge. Due to the possibility of missing a nonunion at either site, we recommend a high clinical suspicion and careful radiographic examination of both fracture sites. Because the development of nonunion at both sites is exceedingly rare, we report three cases of concomitant ipsilateral femoral neck and shaft nonunions that were treated by the senior author (KAE). Two patients were treated with a Pauwels osteotomy and a blade plate for the femoral neck nonunion and a reamed retrograde intramedullary nail for the shaft. One patient was treated with an antegrade reamed cephalomedullary intramedullary nail. All three patients' fractures united at a mean of 4.6 months and they are currently pain free and without physical limitations.
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http://www.ncbi.nlm.nih.gov/pmc/articles/PMC1888598PMC
November 2006

Shoulder function following partial spinal accessory nerve transfer for brachial plexus birth injury.

J Plast Reconstr Aesthet Surg 2006 ;59(4):373-5

Brachial Plexus Program, Miami Children's Hospital, Miami, FL 33176, USA.

Over a 5-year-period, 26 infants underwent a partial transfer of the spinal accessory nerve into the suprascapular nerve using a nerve graft, as part of the repair of a brachial plexus birth injury. At a minimum follow-up of 2.5 years, all children had shoulder function of Grade 4 or better using a modified Gilbert Scale. Average lateral rotation was measured at 53 degrees.
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http://dx.doi.org/10.1016/j.bjps.2005.09.008DOI Listing
June 2006