N6-methyladenosine in 5' UTR does not promote translation initiation.

The most abundant N6-methyladenosine (m6A) modification on mRNAs is installed non-stoichiometrically across transcripts, with 5' untranslated regions (5' UTRs) being the least conductive. 5' UTRs are essential for translation initiation, yet the molecular mechanisms orchestrated by m6A remain poorly understood. Here, we combined structural, biochemical, and single-molecule approaches and show that at the most common position, a single m6A does not affect translation yields, the kinetics of translation initiation complex assembly, or start codon recognition both under permissive growth and following exposure to oxidative stress. Cryoelectron microscopy (cryo-EM) structures of the late preinitiation complex reveal that m6A purine ring established stacking interactions with an arginine side chain of the initiation factor eIF2α, although with only a marginal energy contribution, as estimated computationally. These findings provide molecular insights into m6A interactions with the initiation complex and suggest that the subtle stabilization is unlikely to affect the translation dynamics under homeostatic conditions or stress.

Interaction preferences between protein side chains and key epigenetic modifications 5-methylcytosine, 5-hydroxymethycytosine and N6-methyladenine.

Covalent modifications of standard DNA/RNA nucleobases affect epigenetic regulation of gene expression by modulating interactions between nucleic acids and protein readers. We derive here the absolute binding free energies and analyze the binding modalities between key modified nucleobases 5-methylcytosine (5mC), 5-hydroxymethylcytosine (5hmC) and N6-methyladenine (m6A) and all non-prolyl/non-glycyl protein side chains using molecular dynamics simulations and umbrella sampling in both water and methanol, the latter mimicking the low dielectric environment at the dehydrated nucleic-acid/protein interfaces. We verify the derived affinities by comparing against a comprehensive set of high-resolution structures of nucleic-protein complexes involving 5mC. Our analysis identifies protein side chains that are highly tuned for detecting cytosine methylation as a function of the environment and can thus serve as microscopic readers of epigenetic marks. Conversely, we show that the relative ordering of sidechain affinities for 5hmC and m6A does not differ significantly from those for their precursor bases, cytosine and adenine, respectively, especially in the low dielectric environment. For those two modified bases, the effect is more nuanced and manifests itself primarily at the level of absolute changes in the binding free energy. Our results contribute towards establishing a quantitative foundation for understanding, predicting and modulating the interactions between modified nucleic acids and proteins at the atomistic level.

Sex Differences in Oxycodone/Naloxone vs. Tapentadol in Chronic Non-Cancer Pain: An Observational Real-World Study.

Despite the large body of research on sex differences in pain, there is a lack of translation to real-world pain management. Our aim was to analyse the sex differences in the analgesic response to oxycodone/naloxone (OXN) and tapentadol (TAP), in comparison with other opioids (OPO) commonly prescribed for chronic non-cancer pain (CNCP). An observational and cross-sectional study was conducted on ambulatory CNCP patients (n = 571). Sociodemographic, clinical (pain intensity, relief, and quality of life), safety (adverse events (AEs), adverse drug reactions), hospital frequentations and pharmacological (morphine equivalent daily dose (MEDD)) variables were collected. Multiple linear regressions were carried out to assess the association between sex and outcomes. Sex differences were observed, with lower female tolerability and higher hospital frequentation, especially in the OXN group (OR AEs report = 2.8 [1.8−4.4], p < 0.001). Here, females showed higher hospital use (23% hospital admission, 30% prescription change, p < 0.05), requiring a higher MEDD (127 ± 103 mg/day, p < 0.05), compared to OXN men. Regardless of the opioid group, CNCP women were significantly older than men (three years), with significantly higher benzodiazepine use (OR = 1.6 [1.1−2.3]), more constipation (OR = 1.34 [0.93−1.90]) and headache (OR = 1.45 [0.99−2.13]) AEs, than men who were more likely to refer sexual dysfunction (OR = 2.77 [1.53−5.01]), and loss of libido (OR = 1.93 [1.22−3.04]). Sex-differences were found related to poorer female drug tolerability and higher hospital resources, even worst in OXN female users. Other differences related to older female ages and benzodiazepine prescription, need to be further analysed from a gender perspective.

The evolutionary advantage of an aromatic clamp in plant family 3 glycoside exo-hydrolases.

In the barley ß-D-glucan glucohydrolase, a glycoside hydrolase family 3 (GH3) enzyme, the Trp286/Trp434 clamp ensures ß-D-glucosides binding, which is fundamental for substrate hydrolysis during plant growth and development. We employ mutagenesis, high-resolution X-ray crystallography, and multi-scale molecular modelling methods to examine the binding and conformational behaviour of isomeric ß-D-glucosides during substrate-product assisted processive catalysis that operates in GH3 hydrolases. Enzyme kinetics reveals that the W434H mutant retains broad specificity, while W434A behaves as a strict (1,3)-ß-D-glucosidase. Investigations of reactant movements on the nanoscale reveal that processivity is sensitive to mutation-specific alterations of the tryptophan clamp. While wild-type and W434H utilise a lateral cavity for glucose displacement and sliding of (1,3)-linked hydrolytic products through the catalytic site without dissociation, consistent with their high hydrolytic rates, W434A does not adopt processive catalysis. Phylogenomic analyses of GH3 hydrolases disclose the evolutionary advantage of the tryptophan clamp that confers broad specificity, high catalytic efficiency, and processivity.

Oxycodone/naloxone versus tapentadol in real-world chronic non-cancer pain management: an observational and pharmacogenetic study.

Tapentadol (TAP) and oxycodone/naloxone (OXN) potentially offer an improved opioid tolerability. However, real-world studies in chronic non-cancer pain (CNCP) remain scarce. Our aim was to compare effectiveness and security in daily pain practice, together with the influence of pharmacogenetic markers. An observational study was developed with ambulatory test cases under TAP (n = 194) or OXN (n = 175) prescription with controls (prescribed with other opioids (control), n = 216) CNCP patients. Pain intensity and relief, quality of life, morphine equivalent daily doses (MEDD), concomitant analgesic drugs, adverse events (AEs), hospital frequentation and genetic variants of OPRM1 (rs1799971, A118G) and COMT (rs4680, G472A) genes, were analysed. Test CNCP cases evidenced a significantly higher pain relief predictable due to pain intensity and quality of life (R2 = 0.3), in front of controls. Here, OXN achieved the greatest pain relief under a 28% higher MEDD, 8-13% higher use of pregabalin and duloxetine, and 23% more prescription change due to pain, compared to TAP. Whilst, TAP yielded a better tolerability due the lower number of 4 [0-6] AEs/patient, in front of OXN. Furthermore, OXN COMT-AA homozygotes evidenced higher rates of erythema and vomiting, especially in females. CNCP real-world patients achieved higher pain relief than other traditional opioids with a better tolerability for TAP. Further research is necessary to clarify the potential influence of COMT and sex on OXN side-effects.

Unlocking the Hydrolytic Mechanism of GH92 α-1,2-Mannosidases: Computation Inspires the use of C-Glycosides as Michaelis Complex Mimics.

The conformational changes in a sugar moiety along the hydrolytic pathway are key to understand the mechanism of glycoside hydrolases (GHs) and to design new inhibitors. The two predominant itineraries for mannosidases go via O S2 →B2,5 →1 S5 and 3 S1 →3 H4 →1 C4 . For the CAZy family 92, the conformational itinerary was unknown. Published complexes of Bacteroides thetaiotaomicron GH92 catalyst with a S-glycoside and mannoimidazole indicate a 4 C1 →4 H5 /1 S5 →1 S5 mechanism. However, as observed with the GH125 family, S-glycosides may not act always as good mimics of GH's natural substrate. Here we present a cooperative study between computations and experiments where our results predict the E5 →B2,5 /1 S5 →1 S5 pathway for GH92 enzymes. Furthermore, we demonstrate the Michaelis complex mimicry of a new kind of C-disaccharides, whose biochemical applicability was still a chimera.

Structural and mechanistic insights into the substrate specificity and hydrolysis of GH31 α-N-acetylgalactosaminidase.

Glycoside hydrolase family 31 (GH31) is a diversified family of anomer-retaining α-glycoside hydrolases, such as α-glucosidase and α-xylosidase, among others. Recently, GH31 α-N-acetylgalactosaminidases (Nag31s) have been identified to hydrolyze the core of mucin-type O-glycans and the crystal structure of a gut bacterium Enterococcus faecalis Nag31 has been reported. However, the mechanisms of substrate specificity and hydrolysis of Nag31s are not well investigated. Herein, we show that E. faecalis Nag31 has the ability to release N-acetylgalactosamine (GalNAc) from O-glycoproteins, such as fetuin and mucin, but has low activity against Tn antigen. Mutational analysis and crystal structures of the Michaelis complexes reveal that residues of the active site work in concert with their conformational changes to act on only α-N-acetylgalactosaminides. Docking simulations using GalNAc-attached peptides suggest that the enzyme mainly recognizes GalNAc and side chains of Ser/Thr, but not strictly other peptide residues. Moreover, quantum mechanics calculations indicate that the enzyme preferred p-nitrophenyl α-N-acetylgalactosaminide to Tn antigen and that the hydrolysis progresses through a conformational itinerary, 4C1 → 1S3 → 4C1, in GalNAc of substrates. Our results provide novel insights into the diversification of the sugar recognition and hydrolytic mechanisms of GH31 enzymes.

Virilization and metabolic disease in postmenopausal women related to ovarian hyperplasia and hypertecosis / [Virilización y enfermedad metabólica en mujer postmenopáusica relacionado a hiperplasia e hipertecosis ovárica]

During menopausal transition, mild clinical signs of hyperandrogenism may appear as part of the normal aging process, but the development of frank virilization suggests a specific source of androgen excess. In this context, androgen-secreting tumors at both adrenal and ovarian levels should be ruled out. We present the case of a 51-year-old postmenopausal woman with signs of 12 month period virilization, associated with personal history of type 2 diabetes and arterial hypertension, poorly managed in the past year. Laboratory tests showed elevation of serum androgen levels and hyperinsulinemia. Images were requested, revealing both enlarged homogeneous and solid ovaries, with preserved adrenal glands, which led to suspicion of a possible thecal hyperplasia of the ovarian stroma. Laparoscopic bilateral adnexectomy was performed and the pathological report confirmed the presumptive diagnosis. One month later after surgery, serum testosterone levels returned to values ​​close to spected for a postmenopausal woman. Finding the source of virilization in postmenopausal women is challenging, and they are usually associated with rare pathologies. A detailed medical history is essential to differentiate the progressive development of virilization that characterizes benign causes from the rapid progression that characterizes malignant tumors. The adequate interpretation of laboratory tests with complementary images, as well as looking for the association of pathologies causing elevated cardiovascular risk such as diabetes and hypertension are essential to establish a right diagnosis and treatment.

Durante la transición menopáusica pueden aparecer signos clínicos leves de hiperandrogenismo, como parte del proceso de envejecimiento normal, pero el desarrollo de virilización franca sugiere una fuente específica de exceso de andrógenos debiendo descartar la presencia de tumores secretores de andrógenos tanto a nivel adrenal como ovárico. Se presenta un caso de una mujer de 51 años postmenopáusica con signos de virilización de 12 meses de evolución, asociado a antecedente personal de diabetes tipo 2 e hipertensión arterial, de mal manejo en el último año. Las pruebas de laboratorio mostraron una franca elevación de los niveles de andrógeno sérico e hiperinsulinemia asociada. Las imágenes solicitadas evidenciaron ambos ovarios aumentados de tamaño de aspecto homogéneo y sólido, con glándulas adrenales de aspecto conservado, lo que hizo sospechar de una posible hiperplasia tecal del estroma ovárico. Se realizó una anexectomía bilateral por laparoscopia, cuya anatomía patológica confirmó la presunción diagnóstica. Los dosajes de testosterona sérica al mes de la cirugía retornaron a valores cercanos a la normalidad para una mujer postmenopáusica. El diagnóstico causal de virilización en mujeres posmenopáusicas es un desafío, y por lo general están asociadas con patologías poco frecuentes. Una historia clínica detallada es fundamental para diferenciar el desarrollo progresivo de virilización que caracteriza las causas benignas de la rápida progresión que caracteriza a los tumores malignos. La interpretación de pruebas correctas de laboratorio con imágenes complementarias, así como la búsqueda de antecedentes de riesgo cardiovascular como la diabetes y la hipertensión asociadas son fundamentales para establecer un correcto diagnóstico y tratamiento.

MonteCarbo: A software to generate and dock multifunctionalized ring molecules.

MonteCarbo is an open-source software to construct simple 5-, 6-, and 7-membered ring multifunctionalized monosaccharides and nucleobases and dock them into the active site of carbohydrate-active enzymes. The core bash script executes simple orders to generate the Z-matrix of the neutral molecule of interest. After that, a Fortran90 code based on a pseudo-random number generator (Monte Carlo method) is executed to assign dihedral angles to the different rotamers present in the structure (ring and rotating functional groups). The program also has a generalized internal coordinates (GIC) implementation of the Cremer and Pople puckering coordinates ring. Once the structures are generated and optimized, a second code is ready to execute in serial the docking of multiple conformers in the active site of a wide family of enzymes.

Derivación portosistémica intrahepática transyugular (TIPS) en España. Consideraciones clínicas-epidemiológicas en relación a un registro multicéntrico / No disponible

OBJETIVO: el objetivo del presente estudio es conocer aspectos epidemiológicos, técnicos y clínicos en el uso de la derivación portosistémica intrahepática transyugular (TIPS) en España en las unidades de intervencionismo. Además, se compara el número de TIPS realizados en España con el de otros países. MATERIAL Y MÉTODOS: estudio retrospectivo aprobado por el Comité Ético de la Sociedad Española de Radiología Intervencionista (SERVE). Para la recolección de datos sobre el estado actual del TIPS en España, se preparó una encuesta con 31 ítems (datos demográficos, técnicos y clínicos). La encuesta fue enviada a los 49 hospitales que constaba en el registro de la SERVEI que en 2016 habían realizado TIPS. RESULTADOS: de los 49 centros encuestados, 33 (67,35 %) respondieron. Estos centros habían realizado 265 de los 415 TIPS realizados ese año en España. La indicación más frecuente fue el sangrado por varices gastroesofágicas (144, 54,33 %). El 62,26 % de los TIPS fueron realizados de forma urgente y el 37,7 %, de forma programada. El éxito técnico fue de 89,16 ± 20,9 %, resangrando entre ellos el 17,9 %. Sesenta y nueve pacientes (26,03 %) presentaron complicaciones (el 19,62 % menores y el 6,41 % mayores). La mortalidad a 30 días relacionada con la enfermedad fue del 14,33 %, mientras que a un año fue del 18,49 %. CONCLUSIÓN: de forma llamativa, en nuestro estudio, las complicaciones del TIPS no muestran una clara relación con el número de procedimientos realizados. En relación a otros países como Estados Unidos y Francia, el número de TIPS en España por millón de habitantes actualmente es sustancialmente menor, sin cambios significativos respecto al número realizado en 2013

No disponible

Transjugular intrahepatic portosystemic shunt (TIPS) in Spain. Clinical-epidemiological considerations in relation to a multicenter registry.

OBJECTIVE: this study aimed to determine the epidemiological, technical and clinical data of transjugular intrahepatic portosystemic shunt (TIPS) performed by Interventional Radiology departments in Spain. Furthermore, the total number of TIPS carried out in Spain was determined and compared with other countries. MATERIAL AND METHODS: a retrospective study was performed with the approval of the Ethical Committee of the Spanish Society of Interventional Radiology (SERVEI). A survey was performed with 31 items (demographic, technical and clinical data) for data acquisition on the current status of TIPS in Spain. The survey was sent to the 49 hospitals that SERVEI included in a previous registry with data of TIPS performed in Spain in 2016. RESULTS: of the 49 centers surveyed, 33 (67.35 %) replied to the survey. These centers had completed 265 of the 415 TIPS that year in Spain. The most frequent indication was upper GI bleeding from gastroesophageal varices, which accounted for 144 (54.33 %); 62.26 % of the TIPS were performed urgently and 37.7 % on a scheduled basis. The technical success was 89.16 ± 20.9 %, with a rebleeding rate of 17.9 %. Sixty-nine patients (26.03 %) presented complications, 19.62 % of them minor and 6.41 % major. The 30-day mortality related to the disease was 14.33 %, while mortality at one year was 18.49 %. CONCLUSION: notably in our study, the complications of TIPS did not show a clear relationship with the number of procedures performed. With regard to other countries like the United States and France, the number of TIPS in Spain per million inhabitants is currently substantially lower. There were no significant changes compared to the number completed in 2013.

From Synthetic to Biological Fe4 S4 Complexes: Redox Properties Correlated to Function of Radical S-Adenosylmethionine Enzymes.

By employing the computational protocol for calculation of reduction potentials of the Fe4 S4 -containing species validated using a representative series of well-defined synthetic complexes, we focused on redox properties of two prototypical radical SAM enzymes to reveal how they transform SAM into the reactive 5'-deoxyadenosyl radical, and how they tune this radical for its proper biological function. We found the reduction potential of SAM is indeed elevated by 0.3-0.4 V upon coordination to Fe4 S4 , which was previously speculated in the literature. This makes a generation of 5'-deoxyadenosyl radical from SAM less endergonic (by ca. 7-9 kcal mol-1 ) and hence more feasible in both enzymes as compared to the identical process in water. Furthermore, our calculations indicate that the enzyme-bound 5'-deoxyadenosyl radical has a significantly lower reduction potential than in referential aqueous solution, which may help the enzymes to suppress potential side redox reactions and simultaneously elevate its proton-philic character, which may, in turn, promote the radical hydrogen-atom abstraction ability.

Incidence of Leiomyosarcoma at Surgery for Presumed Uterine Myomas in Different Age Groups.

STUDY OBJECTIVE: To evaluate the incidence of leiomyosarcoma (LMS) at surgery for presumed uterine myomas according to different age groups. DESIGN: A retrospective cohort study. SETTING: A tertiary referral hospital. PATIENTS: All women undergoing surgery for presumed uterine myomas between January 1, 2006, and December 31, 2016. INTERVENTIONS: Laparoscopic myomectomy, laparotomic myomectomy, total hysterectomy, or hysteroscopic myomectomy. MEASUREMENTS AND MAIN RESULTS: A total of 1398 patients underwent surgery for presumed uterine myomas. The incidence of LMS was 2.15 per 1000 surgeries (n = 3, 1/466, 0.2%). In women under 40 years old, the incidence of occult LMS was 0 (0/561). In women between 40 and 49 years old, 190 myomectomies were performed (28% of the surgeries), and the rate of LMS was 1.49 per 1000 (n = 1, 1/673, 0.15%). In women over 49 years old, a total hysterectomy was performed in 82.3% of the cases, and the incidence of LMS was 12.2 per 1000 surgeries (n = 2, 1/82, 1.2%). CONCLUSION: The incidence of occult LMS in patients under 40 years old undergoing surgery for presumed uterine myomas was 0. These findings are suggestive that the use of power morcellation in this population may be safe.

From Ethanolamine Precursor Towards ZnO-How N Is Released from the Experimental and Theoretical Points of View.

This work presents experimental and computational studies on ZnO formation after decomposition of a sol-gel precursor containing ethanolamine and Zn(II) acetate. The structural modifications suffered during decomposition of the monomeric and dimeric Zn(II) complexes formed, containing bidentate deprotonated ethanolamine and acetato ligands, have been described experimentally and explained via Car-Parrinello Molecular Dynamics. Additional metadynamics simulations provide an overview of the dimer evolution by the cleavage of the Zn-N bond, the structural changes produced and their effects on the Zn(II) environment. The results provide conclusive evidence of the relevance of ethanolamine used as a stabilizer in the formation of ZnO.

Trypanosoma cruzi surface mucins are involved in the attachment to the Triatoma infestans rectal ampoule.

BACKGROUND: Trypanosoma cruzi, the agent of Chagas disease, is a protozoan parasite transmitted to humans by blood-sucking triatomine vectors. However, and despite its utmost biological and epidemiological relevance, T. cruzi development inside the digestive tract of the insect remains a poorly understood process. METHODS/PRINCIPLE FINDINGS: Here we showed that Gp35/50 kDa mucins, the major surface glycoproteins from T. cruzi insect-dwelling forms, are involved in parasite attachment to the internal cuticle of the triatomine rectal ampoule, a critical step leading to its differentiation into mammal-infective forms. Experimental evidence supporting this conclusion could be summarized as follows: i) native and recombinant Gp35/50 kDa mucins directly interacted with hindgut tissues from Triatoma infestans, as assessed by indirect immunofluorescence assays; ii) transgenic epimastigotes over-expressing Gp35/50 kDa mucins on their surface coat exhibited improved attachment rates (~2-3 fold) to such tissues as compared to appropriate transgenic controls and/or wild-type counterparts; and iii) certain chemically synthesized compounds derived from Gp35/50 kDa mucins were able to specifically interfere with epimastigote attachment to the inner lining of T. infestans rectal ampoules in ex vivo binding assays, most likely by competing with or directly blocking insect receptor(s). A solvent-exposed peptide (smugS peptide) from the Gp35/50 kDa mucins protein scaffolds and a branched, Galf-containing trisaccharide (Galfß1-4[Galpß1-6]GlcNAcα) from their O-linked glycans were identified as main adhesion determinants for these molecules. Interestingly, exogenous addition of a synthetic Galfß1-4[Galpß1-6]GlcNAcα derivative or of oligosaccharides containing this structure impaired the attachment of Dm28c but not of CL Brener epimastigotes to triatomine hindgut tissues; which correlates with the presence of Galf residues on the Gp35/50 kDa mucins' O-glycans on the former but not the latter parasite clone. CONCLUSION/SIGNIFICANCE: These results provide novel insights into the mechanisms underlying T. cruzi-triatomine interplay, and indicate that inter-strain variations in the O-glycosylation of Gp35/50 kDa mucins may lead to differences in parasite differentiation and hence, in parasite transmissibility to the mammalian host. Most importantly, our findings point to Gp35/50 kDa mucins and/or the Galf biosynthetic pathway, which is absent in mammals and insects, as appealing targets for the development of T. cruzi transmission-blocking strategies.

Conformational Itinerary of Sucrose During Hydrolysis by Retaining Amylosucrase.

By means of QM(DFT)/MM metadynamics we have unraveled the hydrolytic reaction mechanism of Neisseria polysaccharea amylosucrase (NpAS), a member of GH13 family. Our results provide an atomistic picture of the active site reorganization along the catalytic double-displacement reaction, clarifying whether the glycosyl-enzyme reaction intermediate features an α-glucosyl unit in an undistorted 4 C 1 conformation, as inferred from structural studies, or a distorted 1 S 3-like conformation, as expected from mechanistic analysis of glycoside hydrolases (GHs). We show that, even though the first step of the reaction (glycosylation) results in a 4 C 1 conformation, the α-glucosyl unit undergoes an easy conformational change toward a distorted conformation as the active site preorganizes for the forthcoming reaction step (deglycosylation), in which an acceptor molecule, i.e., a water molecule for the hydrolytic reaction, performs a nucleophilic attack on the anomeric carbon. The two conformations (4 C 1 ad E 3) can be viewed as two different states of the glycosyl-enzyme intermediate (GEI), but only the E 3 state is preactivated for catalysis. These results are consistent with the general conformational itinerary observed for α-glucosidases.

Computational Design of Experiment Unveils the Conformational Reaction Coordinate of GH125 α-Mannosidases.

Conformational analysis of enzyme-catalyzed mannoside hydrolysis has revealed two predominant conformational itineraries through B2,5 or 3H4 transition-state (TS) conformations. A prominent unassigned catalytic itinerary is that of exo-1,6-α-mannosidases belonging to CAZy family 125. A published complex of Clostridium perfringens GH125 enzyme with a nonhydrolyzable 1,6-α-thiomannoside substrate mimic bound across the active site revealed an undistorted 4C1 conformation and provided no insight into the catalytic pathway of this enzyme. We show through a purely computational approach (QM/MM metadynamics) that sulfur-for-oxygen substitution in the glycosidic linkage fundamentally alters the energetically accessible conformational space of a thiomannoside when bound within the GH125 active site. Modeling of the conformational free energy landscape (FEL) of a thioglycoside strongly favors a mechanistically uninformative 4C1 conformation within the GH125 enzyme active site, but the FEL of corresponding O-glycoside substrate reveals a preference for a Michaelis complex in an OS2 conformation (consistent with catalysis through a B2,5 TS). This prediction was tested experimentally by determination of the 3D X-ray structure of the pseudo-Michaelis complex of an inactive (D220N) variant of C. perfringens GH125 enzyme in complex with 1,6-α-mannobiose. This complex revealed unambiguous distortion of the -1 subsite mannoside to an OS2 conformation, matching that predicted by theory and supporting an OS2 → B2,5 → 1S5 conformational itinerary for GH125 α-mannosidases. This work highlights the power of the QM/MM approach and identified shortcomings in the use of nonhydrolyzable substrate analogues for conformational analysis of enzyme-bound species.

Nueva mutación descrita en una mujer joven con esplenomegalia, diagnosticada de enfermedad de Niemann-Pick tipo C / New mutation in a young woman diagnosed with Niemann-Pick disease type C

Fundamento y objetivo: Describir una nueva variante molecular del Niemann-Pick tipo C (NPC) en una paciente de 27 años con esplenomegalia y abolición de reflejos osteotendinosos. Material y métodos: NPC1 es el principal gen mutado en el NPC. Presentamos un caso con una nueva mutación, p.N916S, no descrita previamente en pacientes con NPC. Resultados: p.N916S fue descrita como causa de la enfermedad de NPC por los programas predictivos Mutation Master, PolyPhen2 y SIFT. Conclusiones: p.N916S es una nueva mutación detectada como causa de NPC en una paciente sin síntomas neurológicos graves (AU)

Background and objective: To describe a new molecular variant of Niemann-Pick disease type C (NPC) in a 27 year-old patient with splenomegaly and abolition of osteotendinous reflexes. Material and methods: NPC1 is the main gene with described mutation in NPC disease. Here we report a case with a new mutation, p.N916S, not described before in a patient diagnosed with NPC. Results: p.N916S was described as a cause of NPC disease by predictive programmes Mutation Master, PolyPhen2 and SIFT. Conclusions: p.N916S is a new mutation detected as a cause of NPC disease in a patient without severe neurological symptoms (AU)

[New mutation in a young woman diagnosed with Niemann-Pick disease type C]. / Nueva mutación descrita en una mujer joven con esplenomegalia, diagnosticada de enfermedad de Niemann-Pick tipo C.

BACKGROUND AND OBJETIVE: To describe a new molecular variant of Niemann-Pick disease type C (NPC) in a 27 year-old patient with splenomegaly and abolition of osteotendinous reflexes. MATERIAL AND METHODS: NPC1 is the main gene with described mutation in NPC disease. Here we report a case with a new mutation, p.N916S, not described before in a patient diagnosed with NPC. RESULTS: p.N916S was described as a cause of NPC disease by predictive programmes Mutation Master, PolyPhen2 and SIFT. CONCLUSIONS: p.N916S is a new mutation detected as a cause of NPC disease in a patient without severe neurological symptoms.

Von Willebrand Factor Deficiency Corrected by Lung Transplantation.

BACKGROUND: In experimental models with von Willebrand disease pigs, plasma von Willebrand factor (vWF) was significantly increased after lung transplantation because lung endothelial cells strongly express vWF. However, these findings have not been confirmed in human beings. METHODS: A 26-year-old man with mild vWF deficiency (FvW:antigen 39 IU/dL; FvW:ristocetin cofactor activity 44 IU/dL; factor VIII 99%; normal multimeric plasma vWF pattern) was referred to our institution and underwent bilateral lung transplantation for cystic fibrosis. The patient received factor VIII/vWF concentrate both during and after surgery without any relevant bleeding events. At hospital discharge, he was taking immunosuppression with oral tacrolimus, prednisone, and mycophenolate mofetil, which has continued until the present day (22 months after the procedure). RESULTS: Plasma vWF level increased during the postoperative days, presumably due to endothelial injuries and the infusion of vWF concentrate. Laboratory tests at 5, 11, 14, and 22 months after lung transplantation demonstrated sustained normalization of all parameters. CONCLUSIONS: To our knowledge, this is the first reported case of von Willebrand deficiency corrected through lung transplantation.