Spontaneous Atomic-Scale Polar Skyrmions and Merons on a SrTiO3 (001) Surface: Defect Engineering for Emerging Topological Orders.

The emergence of nontrivial topological order in condensed matter has been attracting a great deal of attention owing to its promising technological applications in novel functional nanodevices. In ferroelectrics, the realization of polar topological order at an ultimately small scale is extremely challenging due to the lack of chiral interaction and the critical size of the ferroelectricity. Here, we break through these limitations and demonstrate that the ultimate atomic-scale polar skyrmion and meron (∼2 nm) can be induced by engineering oxygen vacancies on the SrTiO3 (001) surface based on first-principles calculations. The paraelectric-to-antiferrodistortive phase transition leads to a novel topological transition from skyrmion to meron, indicating phase-topology correlations. We also discuss accumulating and driving polar skyrmions based on the oxygen divacancy model; these results and the recent discovery of defect engineering techniques suggest the possibility of arithmetic operations on topological numbers through the natural self-organization and diffusion features of oxygen vacancies.

Crystal structure of mango α1,3/α1,4-fucosyltransferase elucidates unique elements that regulate Lewis A-dominant oligosaccharide assembly.

In various organisms, α1,3/α1,4-fucosyltransferases (CAZy GT10 family enzymes) mediate the assembly of type I (Galß1,3GlcNAc) and/or type II (Galß1,4GlcNAc)-based Lewis structures that are widely distributed in glycoconjugates. Unlike enzymes of other species, plant orthologues show little fucosyltransferase activity for type II-based glycans and predominantly catalyze the assembly of the Lewis A structure [Galß1,3(Fucα1,4)GlcNAc] on the type I disaccharide unit of their substrates. However, the structural basis underlying this unique substrate selectivity remains elusive. In this study, we investigated the structure-function relationship of MiFUT13A, a mango α1,3/α1,4-fucosyltransferase. The prepared MiFUT13A displayed distinct α1,4-fucosyltransferase activity. Consistent with the enzymatic properties of this molecule, X-ray crystallography revealed that this enzyme has a typical GT-B fold-type structure containing a set of residues that are responsible for its SN2-like catalysis. Site-directed mutagenesis and molecular docking analyses proposed a rational binding mechanism for type I oligosaccharides. Within the catalytic cleft, the pocket surrounding Trp121 serves as a binding site, anchoring the non-reducing terminal ß1,3-galactose that belongs to the type I disaccharide unit. Furthermore, Glu177 was postulated to function as a general base catalyst through its interaction with the 4-hydroxy group of the acceptor N-acetylglucosamine residue. Adjacent residues, specifically Thr120, Thr157 and Asp175 were speculated to assist in binding of the reducing terminal residues. Intriguingly, these structural elements were not fully conserved in mammalian orthologue which also shows predominant α1,4-fucosyltransferase activity. In conclusion, we have proposed that MiFUT13A generates the Lewis A structure on type I glycans through a distinct mechanism, divergent from that of mammalian enzymes.

The Emerging Roles of γ-Glutamyl Peptides Produced by γ-Glutamyltransferase and the Glutathione Synthesis System.

L-γ-Glutamyl-L-cysteinyl-glycine is commonly referred to as glutathione (GSH); this ubiquitous thiol plays essential roles in animal life. Conjugation and electron donation to enzymes such as glutathione peroxidase (GPX) are prominent functions of GSH. Cellular glutathione balance is robustly maintained via regulated synthesis, which is catalyzed via the coordination of γ-glutamyl-cysteine synthetase (γ-GCS) and glutathione synthetase, as well as by reductive recycling by glutathione reductase. A prevailing short supply of L-cysteine (Cys) tends to limit glutathione synthesis, which leads to the production of various other γ-glutamyl peptides due to the unique enzymatic properties of γ-GCS. Extracellular degradation of glutathione by γ-glutamyltransferase (GGT) is a dominant source of Cys for some cells. GGT catalyzes the hydrolytic removal of the γ-glutamyl group of glutathione or transfers it to amino acids or to dipeptides outside cells. Such processes depend on an abundance of acceptor substrates. However, the physiological roles of extracellularly preserved γ-glutamyl peptides have long been unclear. The identification of γ-glutamyl peptides, such as glutathione, as allosteric modulators of calcium-sensing receptors (CaSRs) could provide insights into the significance of the preservation of γ-glutamyl peptides. It is conceivable that GGT could generate a new class of intercellular messaging molecules in response to extracellular microenvironments.

A case of juvenile form of dilated cardiomyopathy in a 6-month-old Shiba Inu dog.

A 6-month-old Shiba Inu dog was brought to the Veterinary Medical Teaching Hospital because of a cough, exercise intolerance, and pulmonary edema. The dog had a Levine 2/6 systolic murmur. Transthoracic echocardiography revealed left atrial and ventricular dilatation (left atrium to aortic ratio: 2.8), mitral and tricuspid valve regurgitation, and severe left ventricular myocardial hypokinesia (fractional shortening was 11.8%). Bubble contrast echocardiography did not reveal a congenital shunt; therefore, the dog was clinically diagnosed with early onset dilated cardiomyopathy. From the first visit, the dog was treated with pimobendan, taurine, torasemide, and isosorbide dinitrate. After 435 days, echocardiography revealed that systolic function had not improved. On Day 465, atrial fibrillation was confirmed via electrocardiogram, and treatment with diltiazem hydrochloride was initiated. The dog continued to appear clinically stable thereafter, until it died suddenly 1087 days after the initial visit. A postmortem histopathological examination identified severe enlargement of the left atrial and ventricular chambers as well as attenuated wavy fibers in the ventricular myocardium, which confirmed dilated cardiomyopathy in a juvenile. This is the first report of a juvenile form of dilated cardiomyopathy in a Shiba Inu dog. This case report provides evidence that the extended prognosis of this dog differed from that in previously reported cases of dilated cardiomyopathy in young dogs. Key clinical message: This is the first reported case of a juvenile form of dilated cardiomyopathy in a Shiba Inu dog. This report provides evidence that the prognosis of this dog differed from that in previously reported cases of dilated cardiomyopathy in young dogs.

Un cas de forme juvénile de cardiomyopathie dilatée chez un chien Shiba Inu de 6 mois. Un chien Shiba Inu de 6 mois a été amené à l'hôpital universitaire de médecine vétérinaire en raison d'une toux, d'une intolérance à l'exercice et d'un oedème pulmonaire. Le chien avait un souffle systolique Levine 2/6. L'échocardiographie transthoracique a révélé une dilatation auriculaire et ventriculaire gauche (rapport oreillette gauche sur aorte : 2,8), une régurgitation des valves mitrale et tricuspide et une hypokinésie myocardique ventriculaire gauche sévère (raccourcissement fractionnel de 11,8 %). L'échocardiographie de contraste par microbulles n'a pas révélé de shunt congénital; par conséquent, le chien a reçu un diagnostic clinique de cardiomyopathie dilatée d'apparition précoce. Dès la première visite, le chien a été traité avec du pimobendane, de la taurine, du torasémide et du dinitrate d'isosorbide. Après 435 jours, l'échocardiographie a révélé que la fonction systolique ne s'était pas améliorée. Au jour 465, la fibrillation auriculaire a été confirmée par électrocardiogramme et un traitement par le chlorhydrate de diltiazem a été instauré. Le chien a continué à apparaître cliniquement stable par la suite, jusqu'à ce qu'il meure subitement 1087 jours après la visite initiale. Un examen histopathologique post mortem a identifié une hypertrophie sévère des cavités auriculaire et ventriculaire gauche ainsi que des fibres ondulées atténuées dans le myocarde ventriculaire, ce qui a confirmé une cardiomyopathie dilatée chez un juvénile. Il s'agit du premier rapport d'une forme juvénile de cardiomyopathie dilatée chez un chien Shiba Inu. Ce rapport de cas fournit des preuves que le pronostic prolongé de ce chien différait de celui des cas précédemment rapportés de cardiomyopathie dilatée chez les jeunes chiens.Message clinique clé :Il s'agit du premier cas rapporté d'une forme juvénile de cardiomyopathie dilatée chez un chien Shiba Inu. Ce rapport fournit des preuves que le pronostic de ce chien différait de celui des cas précédemment rapportés de cardiomyopathie dilatée chez les jeunes chiens.(Traduit par Dr Serge Messier).

True significance of N-acetylglucosaminyltransferases GnT-III, V and α1,6 fucosyltransferase in epithelial-mesenchymal transition and cancer.

It is well known that numerous cancer-related changes occur in glycans that are attached to glycoproteins, glycolipids and proteoglycans on the cell surface and these changes in structure and the expression of the glycans are largely regulated by glycosyl-transferases, glycosidases, nucleotide sugars and their related genes. Such structural changes in glycans on cell surface proteins may accelerate the progression, invasion and metastasis of cancer cells. Among the over 200 known glycosyltransferases and related genes, ß 1,6 N-acetylglucosaminyltransferase V (GnT-V) (the MGAT5 gene) and α 1,6 fucosyltransferase (FUT8) (the FUT8 gene) are representative enzymes in this respect because changes in glycans caused by these genes appear to be related to cancer metastasis and invasion in vitro as well as in vivo, and a number of reports on these genes in related to epithelial-mesenchymal transition (EMT) have also appeared. Another enzyme, one of the N-glycan branching enzymes, ß1,4 N-acetylglucosaminyltransferase III (GnT-III) (the MGAT3 gene) has been reported to suppress EMT. However, there are intermediate states between EMT and mesenchymal-epithelial transition (MET) and some of these genes have been implicated in both EMT and MET and are also probably in an intermediate state. Therefore, it would be difficult to clearly define which specific glycosyltransferase is involved in EMT or MET or an intermediate state. The significance of EMT and N-glycan branching glycosyltransferases needs to be reconsidered and the inhibition of their corresponding genes would also be desirable in therapeutics. This review mainly focuses on GnT-III, GnT-V and FUT8, major players as N-glycan branching enzymes in cancer in relation to EMT programs, and also discusses the catalytic mechanisms of GnT-V and FUT8 whose crystal structures have now been obtained.

γ-Glutamylcysteine synthetase and γ-glutamyl transferase as differential enzymatic sources of γ-glutamylpeptides in mice.

Some γ-glutamylpeptides in blood plasma are putative biomarkers for pathological conditions of the liver. γ-Glutamyltransferase (GGT) and γ-glutamylcysteine synthetase (γ-GCS) are two such potential enzymes that are responsible for the production of γ-glutamylpeptides. GGT produces γ-glutamylpeptides by transferring the γ-glutamyl moiety from glutathione to an amino acid or a peptide. γ-GCS normally catalyzes the production of γ-glutamylcysteine from glutamate and cysteine in the glutathione-synthesizing reaction, but other amino acids can also serve as an acceptor of a γ-glutamyl group, thus resulting in the formation of a variety of γ-glutamylpeptides. Based on liquid chromatography-mass spectrometry analyses, we observed differences in the distribution of γ-glutamylpeptides between the liver and kidney and were able to measure the activities of γ-GCS as well as the GGT reactions by quantifying the resulting γ-glutamylpeptides. The enzymatic characterization of γ-GCS in liver homogenates indicated that several γ-glutamylpeptides including γ-glutamyltaurine are actually produced. Cys showed the lowest Km value (0.06 mM) while other amino acids had much higher Km values (ranging from 21 to 1800 mM). The moderate Km values for these amino acids suggest that they were not the preferred amino acids in this conversion but were utilized as acceptor substrates for the production of the corresponding γ-glutamylpeptides by the γ-GCS reaction under Cys-deficient conditions. Thus, the production of these γ-glutamylpeptides by γ-GCS is directly correlated with a low Cys content, suggesting that their measurement in blood plasma could be useful for predicting the presymptomatic disease state of the liver with a defect in GSH redox balance.

Involvement of the α-helical and Src homology 3 domains in the molecular assembly and enzymatic activity of human α1,6-fucosyltransferase, FUT8.

BACKGROUND: Previous structural analyses showed that human α1,6-fucosyltransferase, FUT8 contains a catalytic domain along with two additional domains, N-terminal α-helical domain and C-terminal Src homology 3 domain, but these domains are unique to FUT8 among glycosyltransferases. The role that these domains play in formation of the active form of FUT8 has not been investigated. This study reports on attempts to determine the involvement of these domains in the functions of FUT8. METHODS: Based on molecular modeling, the domain mutants were constructed by truncation and site-directed mutagenesis, and were heterologously expressed in Sf21 or COS-1 cells. The mutants were analyzed by SDS-PAGE and assayed for enzymatic activity. In vivo cross-linking experiments by introducing disulfide bonds were also carried out to examine the orientation of the domains in the molecular assembly. RESULTS: Mutagenesis and molecular modeling findings suggest that human FUT8 potentially forms homodimer in vivo via intermolecular hydrophobic interactions involving α-helical domains. Truncation or site-directed mutagenesis findings indicated that α-helical and SH3 domains are all required for enzymatic activity. In addition, in vivo cross-linking experiments clearly indicated that the SH3 domain located in close proximity to the α-helical domain in an intermolecular manner. CONCLUSIONS: α-Helical and SH3 domains are required for a fully active enzyme, and are also involved in homophilic dimerization, which probably results in the formation of the active form of human FUT8. GENERAL SIGNIFICANCE: α-Helical and SH3 domains, which are not commonly found in glycosyltransferases, play roles in the formation of the functional quaternary structure of human FUT8.

Characterization of MiFUT11 from Mangifera indica L.: A functional core α1,3-fucosyltransferase potentially involved in the biosynthesis of immunogenic carbohydrates in mango fruit.

In higher plants, asparagine-linked oligosaccharides (N-glycans) in glycoproteins carry unique carbohydrate epitopes, namely, a core α1,3-fucose and/or a ß1,2-xylose, which are common determinants responsible for the cross-reactivity of plant glycoproteins due to their strong immunogenicity. While these determinants and the relevant genes have been well characterized for herbaceous plants, information concerning whether many food plants cross-react with airborne pollens is not available. In this paper, we report on the characterization of a novel core α1,3-fucosyltransferase gene identified from Mangifera indica L., one of the major plants potentially related to food allergy. Based on sequence information of plant homologues, we amplified a candidate cDNA (MiFUT11) from pericarp tissue. An in vitro assay demonstrated that the recombinant MiFUT11 protein transfers a fucose unit onto both non-fucosylated and core α1,6-fucosylated oligosaccharides. A glycoform analysis using MALDI-TOF mass spectrometry showed that the introduction of the MiFUT11 cDNA increased the production of a core α1,3- and α1,6-fucosylated pauci-mannosidic oligosaccharide in Spodoptera Sf21 cells. Our findings suggest that MiFUT11 is a functional core α1,3-fucosyltransferase gene that is involved in the assembly of cross-reactive N-glycans in mango fruit.

Quantitative analysis of γ-glutamylpeptides by liquid chromatography-mass spectrometry and application for γ-glutamyltransferase assays.

γ-Glutamylpeptides are largely produced via the action of γ-glutamylcysteine synthetase or γ-glutamyltransferase (GGT). GGT transfers the γ-glutamyl moiety from glutathione (GSH) and other γ-glutamyl compounds to amino acids, peptides, or water. A conventional GGT assay employs a synthetic donor substrate, which facilitates monitoring cleavage activity by means of colorimetric analyses but provides no information on the resulting γ-glutamylpeptides. In this study, we report on the use of liquid chromatography-mass spectrometry (LC-MS) to quantitatively measure the levels of 21 γ-glutamylpeptides including GSH and 45 amino acids, including Cys. Authentic compounds consisting of 17 chemically synthesized and commercially available 4 γ-glutamylpeptides were adopted as references. We applied this method to the characterization of γ-glutamylpeptides in blood plasma and livers of mice that had been treated with an overdose of acetaminophen. The established LC-MS-based assay was found to be useful for characterizing the γ-glutamylation reaction under in vivo and in vitro conditions and was clearly helpful for understanding the physiological significance of the production of γ-glutamylpeptides.

The Combination Of Weak Expression Of PRDX4 And Very High MIB-1 Labelling Index Independently Predicts Shorter Disease-free Survival In Stage I Lung Adenocarcinoma.

Background: Oxidative stress plays pivotal roles in the progression of lung adenocarcinoma (LUAD) through cell signaling related closely to cancer growth. We previously reported that peroxiredoxin 4 (PRDX4), a secretory-type antioxidant enzyme, can protect against the development of various diseases, including potential malignancies. Since many patients with early-stage LUAD develop recurrence, even after curative complete resection, we investigated the association of the PRDX4 expression with the clinicopathological features and recurrence/prognosis using post-surgical samples of stage I-LUAD. Methods: The expression of PRDX4 and MIB-1, a widely accepted Ki67 protein, was immunohistochemically analysed in 206 paraffin-embedded tumour specimens of patients with stage I-LUAD. The PRDX4 expression was considered to be weak when less than 25% of the adenocarcinoma cells showed positive staining. Results: A weak PRDX4+ expression demonstrated a significantly close relationship with pathologically poor differentiation, highly invasive characteristics and recurrence. The decrease in PRDX4-positivity potentially induced cell growth in LUAD, which was correlated significantly with a very high MIB-1 labelling index (≥17.3%). Univariate/multivariate analyses revealed that the subjects with both weak PRDX4+ expression and a very high MIB-1 index had significantly worse disease-free survival rates than other subjects. Conclusions: The combination of weak PRDX4 expression and a very high MIB-1 index can predict high proliferating activity and recurrence with a potential poor prognosis, especially in post-operative stage I-LUAD patients.

Midterm Outcomes of Endovascular Aortic Aneurysm Repair with Carbon Dioxide-Guided Angiography.

BACKGROUND: Although iodinated contrast (IC) agents are commonly used in endovascular aneurysm repair (EVAR), perioperative use in patients with renal dysfunction or IC allergies is avoided. Carbon dioxide (CO2)-guided angiography is a promising alternative. We aimed to evaluate short-term and midterm outcomes of EVAR using CO2-guided angiography. METHODS: Three hundred eighty-one patients who underwent EVAR from January 2012 to September 2016 were retrospectively reviewed and divided into an IC-EVAR group (n = 351) and CO2-EVAR group (n = 30). Subjects in the CO2-EVAR group had severe renal dysfunction (n = 27) and IC allergy (n = 4). Intraoperative, postoperative, and follow-up variables were compared. RESULTS: Compared with the IC-EVAR group, preoperative serum creatinine level was significantly higher (2.0 vs. 0.92 mg/dL, P < 0.0001) and mean IC dose was significantly lower (18 vs. 55 mL, P < 0.0001) in the CO2-EVAR group. The fluoroscopy time, operative time, number of stent grafts placed, and technical success rates of the groups were similar; no type I and/or type III endoleaks were detected on completion angiography. There was no acute kidney injury and one case of intestinal necrosis in the CO2-EVAR group, potentially due to cholesterol embolism. Postoperative endoleak, enlargement of aneurysms, survival, freedom from secondary intervention, and renal function change up to 3 months, postoperatively, were similar between the groups. CONCLUSIONS: CO2-EVAR is technically feasible and exhibits prominent renal protection. However, consideration of the aortic lumen status remains an important challenge.

Molecular cloning and functional expression of Lewis type α1,3/α1,4-fucosyltransferase cDNAs from Mangifera indica L.

In higher plants, complex type N-glycans contain characteristic carbohydrate moieties that are not found in mammals. In particular, the attachment of the Lewis a (Lea) epitope is currently the only known outer chain elongation that is present in plant N-glycans. Such a modification is of great interest in terms of the biological function of complex type N-glycans in plant species. However, little is known regarding the exact molecular basis underlying their Lea expression. In the present study, we cloned two novel Lewis type fucosyltransferases (MiFUT13) from mango fruit, Mangifera indica L., heterologously expressed the proteins and structurally and functionally characterized them. Using an HPLC-based assay, we demonstrated that the recombinant MiFUT13 proteins mediate the α1,4-fucosylation of acceptor tetrasaccharides with a strict preference for type I-based structure to type II. The results and other findings suggest that MiFUT13s are involved in the biosynthesis of Lea containing glycoconjugates in mango fruits.

Outcomes of gastrointestinal defect closure with an over-the-scope clip system in a multicenter experience: An analysis of a successful suction method.

AIM: To demonstrate the clinical outcomes of a multicenter experience and to suggest guidelines for choosing a suction method. METHODS: This retrospective study at 5 medical centers involved 58 consecutive patients undergoing over-the-scope clips (OTSCs) placement. The overall rates of technical success (TSR), clinical success (CSR), complications, and procedure time were analyzed as major outcomes. Subsequently, 56 patients, excluding two cases that used the Anchor device, were divided into two groups: 14 cases of simple suction (SS-group) and 42 cases using the Twin Grasper (TG-group). Secondary evaluation was performed to clarify the predictors of OTSC success. RESULTS: The TSR, CSR, complication rate, and median procedure time were 89.7%, 84.5%, 1.8%, and 8 (range 1-36) min, respectively, demonstrating good outcomes. However, significant differences were observed between the two groups in terms of the mean procedure time (5.9 min vs 14.1 min). The CSR of the SS- and TG-groups among cases with a maximum defect size ≤ 10 mm and immediate or acute refractory bleeding was 100%, which suggests that SS is a better method than TG in terms of time efficacy. The CSR in the SS-group (78.6%), despite the technical success of the SS method (TSR, 100%), tended to decrease due to delayed leakage compared to that in the TG-group (TSR, CSR; 88.1%), indicating that TG may be desirable for leaks and fistulae with defects of the entire layer. CONCLUSION: OTSC system is a safe and effective therapeutic option for gastrointestinal defects. Individualized selection of the suction method based on particular clinical conditions may contribute to the improvement of OTSC success.

Synthesis and Biological Evaluation of Cyclopentaquinoline Derivatives as Nonsteroidal Glucocorticoid Receptor Antagonists.

The steroidal glucocorticoid antagonist mifepristone has been reported to improve the symptoms of depression. We report the discovery of 6-(3,5-dimethylisoxazol-4-yl)-2,2,4,4-tetramethyl-2,3,4,7,8,9-hexahydro-1H-cyclopenta[h]quinolin-3-one 3d (QCA-1093) as a novel nonsteroidal glucocorticoid receptor antagonist. The compound displayed potent in vitro activity, high selectivity over other steroid hormone receptors, and significant antidepressant-like activity in vivo.

Preparation of optically pure δ-lactones using diastereomeric resolution with amino acid as resolving agent.

Synthesis of optically pure δ-lactones by diastereomeric resolution was investigated. Amino acid derivatives, which can be obtained at a relatively low cost, were used as resolving agents. Six optically pure δ-lactones were efficiently synthesized using Cbz-L-alanine without other expensive resolving agents. Both enantiomers of δ-lactone obtained had over 98% enantiomeric excesses. This diastereomeric resolution is very efficient for the preparation of optically pure δ-lactones.

Physiological and pathological views of peroxiredoxin 4.

Peroxiredoxins (PRDXs) form an enzyme family that exhibits peroxidase activity using electrons from thioredoxin and other donor molecules. As the signaling roles of hydrogen peroxide in response to extracellular stimuli have emerged, the involvement of PRDX in the hydrogen peroxide-mediated signaling has become evident. Among six PRDX members in mammalian cells, PRDX4 uniquely possesses a hydrophobic signal peptide at the amino terminus, and, hence, it undergoes either secretion or retention by the endoplasmic reticulum (ER) lumen. The role of PRDX4 as a sulfoxidase in ER is now attracting much attention regarding the oxidative protein folding of nascent proteins. Contrary to this role in the ER, the functional significance of PRDX4 in the extracellular milieu is virtually unknown despite its implications as a biomarker under pathological conditions in some diseases. Other than its systemically expressed form, a variant form of PRDX4 is transcribed from the upstream promoter/exon 1 of the systemic promoter/exon 1 and is uniquely expressed in sexually matured testes. Circumstantial evidence, together with deduced functions from the systemic form, suggests that there are potential roles for testicular PRDX4 in the reproductive processes such as the regulation of hormonal signals and the oxidative packaging of sperm chromatin. Elucidation of these PRDX4 functions under in vivo situations is expected to show the whole picture of how PRDX4 has evolved in multicellular organisms.

A case of incarcerated umbilical hernia in an adult treated by laparoscopic surgery.

A 42-year-old, obese woman was admitted to our hospital 3 h after the sudden development of abdominal pain. Her umbilical region was swollen and she was diagnosed with incarceration of an umbilical hernia by computed tomography. Although we tried, we were unable to reduce the hernia with a manipulative procedure. We decided to perform an emergency laparoscopy. Once general anesthesia was induced, we achieved hernia reduction. From a laparoscopic view, the portion of strangulated small intestine was neither necrotic nor perforated. The size of the hernial orifice was ∼2 × 2 cm, and thus, we selected a 12 × 12 cm composite mesh to cover the hernia defect by at least 5 cm in all directions. The surgical procedure was uneventful and the total operation time was 112 min. The patient recovered uneventfully and was discharged on postoperative day 9. She remains free of recurrence 20 months after surgery.