SUMO Conjugation and SUMO Chain Formation by Plant Enzymes.

SUMO conjugation is a conserved process of eukaryotes, and essential in metazoa. Similar to ubiquitylation, a SUMO-activating enzyme links to the SUMO carboxyl-terminal Gly in a thioester bond, and a SUMO-conjugating enzyme accepts activated SUMO and can transfer it to substrates. Unlike ubiquitylation, this transfer can also occur, in an unspecified number of cases, in the absence of ligase-like enzymes. Different isoforms of SUMO are present in eukaryotic genomes. Saccharomyces cerevisiae has only one SUMO protein, humans have four, and Arabidopsis thaliana has eight, the main isoforms being SUMO1 and SUMO2 with about 95% identity. Functionally similar to human SUMO2 and SUMO3, Arabidopsis SUMO1 and 2 can be transferred to substrates as single moieties, but can also form SUMO chains, a process enhanced by chain-forming ligases. By combined action with SUMO chain recognizing ubiquitin ligases, chains can channel substrates into the ubiquitin-dependent degradation pathway.A method is described to sumoylate substrates and to generate SUMO chains, using plant enzymes produced in E. coli. In vitro SUMO chain formation may serve for further analysis of SUMO chain functions. It can also provide an easy-to-synthesize substrate for SUMO-specific proteases.

Neutropenic fever of unknown origin and disseminated granulomatous disease in a patient with acute lymphoblastic leukemia.

An 18-year-old male was admitted for his second induction chemotherapy treatment for an acute lymphoblastic leukaemia with cyclophosphamide, cytarabine, and mercaptopurine. He presented with high fever, abdominal pain, non-bloody diarrhoea, portal hypertension and leukopenia. Stool sample analysis, blood cultures and extensive work-up were negative. The only microbiologic evidence was the presence of cytomegalovirus DNA detected by PCR. A profound hypogammaglobulinemia was documented. Pathology material reported non-caseating granulomas in liver, bone marrow, duodenum and colon with negative cytomegalovirus immunostaining. What is your diagnosis?

Un varón de 18 años se internó para recibir el segundo ciclo de inducción por una leucemia linfoblástica aguda con ciclofosfamida, citarabina y mercaptopurina. Desarrolló fiebre alta, dolor abdominal, diarrea no sanguinolenta, hipertensión portal y leucopenia. El análisis de materia fecal, cultivos de sangre y una evaluación exhaustiva fueron negativas. La única evidencia microbiológica fue la detección de ADN de citomegalovirus en sangre por PCR. También se documentó una hipogamaglobulinemia profunda. El material de patología reportó granulomas no caseificantes en hígado, médula ósea, duodeno y colon con inmunohistoquímica negativa para citomegalovirus. ¿Cuál es su diagnóstico?

[Hepatitis associated aplastic anemia during SARS-CoV-2 pandemic]. / Anemia aplásica asociada a hepatitis durante la pandemia por SARS-CoV-2.

The hepatitis-associated aplastic anemia is one of the acquired bone marrow failure syndromes. It is a stereotyped form of presentation of aplastic anemia and accounts for 2 - 5 % of the cases in the West. Its treatment, which does not differ from that of aplastic anemia, consists of immunosuppression when bone marrow transplant is not possible. Nonetheless, during the SARS-CoV-2 pandemic, recommendations restricting the use of antithymocyte globulin to those cases with the highest risk of death have been issued, since the prognosis of CoViD-19 tends to be worse if administered. We present an otherwise-healthy 18-year-old male who was diagnosed with a hepatitis-associated aplastic anemia and received a personalized treatment following these recommendations.

La anemia aplásica asociada a hepatitis es uno de los síndromes de fallo medular adquirido. Es una forma estereotipada de presentación de la anemia aplásica adquirida y representa el 2 - 5 % de los casos en occidente. Su tratamiento, que no difiere del de la anemia aplásica adquirida, consiste en inmunosupresión cuando el trasplante de células progenitoras hematopoyéticas no es posible. Sin embargo, durante la pandemia por SARS-CoV-2 se han publicado recomendaciones mediante las cuales se restringe el uso de globulina antitimocítica para aquellos casos con riesgo de muerte porque el pronóstico de la CoViD-19 tiende a ser peor con su uso. Presentamos el caso de un varón de 18 años previamente sano a quien se le diagnosticó una anemia aplásica asociada a hepatitis y se le personalizó el tratamiento acorde a estas recomendaciones.

Affinity Purification of Ubiquitinated Proteins Using p62-Agarose to Assess Ubiquitination of Clade A PP2Cs.

Certain E3 ubiquitin ligases play a key role in the abscisic acid (ABA) pathway by targeting clade A type 2C protein phosphatases (PP2Cs) for degradation. At early stages of ABA signaling, degradation of PP2Cs is a complementary step to PP2Cs inhibition by ABA receptors. At later steps, protein levels of PP2Cs are increased as a negative feedback mechanism. Subsequently, E3 ligases targeting PP2Cs are critical to recover the basal PP2C levels and reset the ABA signaling. BTB/POZ AND MATH DOMAIN proteins (BPMs) are substrate adaptors of a multimeric cullin3-RING based E3 ligase and target for degradation clade A PP2Cs. In this chapter, we provide a detailed protocol to assess the ubiquitination of PP2CA, a clade A PP2C, mediated by BPMs using agarose-immobilised p62-derived ubiquitin-associated (UBA) domain, which efficiently binds ubiquitinated proteins.

Ubiquitylation of ABA Receptors and Protein Phosphatase 2C Coreceptors to Modulate ABA Signaling and Stress Response.

Post-translational modifications play a fundamental role in regulating protein function and stability. In particular, protein ubiquitylation is a multifaceted modification involved in numerous aspects of plant biology. Landmark studies connected the ATP-dependent ubiquitylation of substrates to their degradation by the 26S proteasome; however, nonproteolytic functions of the ubiquitin (Ub) code are also crucial to regulate protein interactions, activity, and localization. Regarding proteolytic functions of Ub, Lys-48-linked branched chains are the most common chain type for proteasomal degradation, whereas promotion of endocytosis and vacuolar degradation is triggered through monoubiquitylation or Lys63-linked chains introduced in integral or peripheral plasma membrane proteins. Hormone signaling relies on regulated protein turnover, and specifically the half-life of ABA signaling components is regulated both through the ubiquitin-26S proteasome system and the endocytic/vacuolar degradation pathway. E3 Ub ligases have been reported that target different ABA signaling core components, i.e., ABA receptors, PP2Cs, SnRK2s, and ABFs/ABI5 transcription factors. In this review, we focused specifically on the ubiquitylation of ABA receptors and PP2C coreceptors, as well as other post-translational modifications of ABA receptors (nitration and phosphorylation) that result in their ubiquitination and degradation.

PYL8 ABA receptors of Phoenix dactylifera play a crucial role in response to abiotic stress and are stabilized by ABA.

The identification of those prevalent abscisic acid (ABA) receptors and molecular mechanisms that trigger drought adaptation in crops well adapted to harsh conditions such as date palm (Phoenix dactylifera, Pd) sheds light on plant-environment interactions. We reveal that PdPYL8-like receptors are predominantly expressed under abiotic stress, with Pd27 being the most expressed receptor in date palm. Therefore, subfamily I PdPYL8-like receptors have been selected for ABA signaling during abiotic stress response in this crop. Biochemical characterization of PdPYL8-like and PdPYL1-like receptors revealed receptor- and ABA-dependent inhibition of PP2Cs, which triggers activation of the pRD29B-LUC reporter in response to ABA. PdPYLs efficiently abolish PP2C-mediated repression of ABA signaling, but loss of the Trp lock in the seed-specific AHG1-like phosphatase PdPP2C79 markedly impairs its inhibition by ABA receptors. Characterization of Arabidopsis transgenic plants that express PdPYLs shows enhanced ABA signaling in seed, root, and guard cells. Specifically, Pd27-overexpressing plants showed lower ABA content and were more efficient than the wild type in lowering transpiration at negative soil water potential, leading to enhanced drought tolerance. Finally, PdPYL8-like receptors accumulate after ABA treatment, which suggests that ABA-induced stabilization of these receptors operates in date palm for efficient boosting of ABA signaling in response to abiotic stress.

Giant solitary extradural plasmacytoma of the skull: illustrative case.

BACKGROUND: Solitary extradural plasmacytoma of the skull (SEPS) is an extremely rare entity with only 35 cases reported in the English-language literature. SEPS is a rare presentation of plasma cell dyscrasias, accounting for 4% of plasma cell tumors. The diagnosis of solitary plasmacytoma requires exclusion of multiple myeloma (MM) and prompt diagnosis and treatment. OBSERVATIONS: The authors describe the case of a 52-year-old man with SEPS. He presented with a painless, progressive, soft swelling mass in the left parietal region. Magnetic resonance imaging revealed a left frontotemporal extra-axial lesion that involved the ipsilateral orbital apex and posterior ethmoidal cells. Biological studies did not reveal features suggestive of MM. A diagnosis of SEPS was based on microscopic examination and immunohistochemical analysis after surgery. The patient had an excellent recovery and was discharged the day after surgery without neurological deficit. LESSONS: SEPS is a potentially curable disease, and total resection with or without radiotherapy is associated with a good prognosis and long-term recurrence-free survival. Distinction between SEPS and MM is of paramount importance because the prognosis and treatment differ.

Academic Achievement and Physical Activity: The Ideal Relationship to Promote a Healthier Lifestyle in Adolescents.

BACKGROUND: School environment provides several intervention opportunities for physical activity. The aim of this study was to examine the relationship between objectively assessed moderate to vigorous physical activity (MVPA) and academic achievement in adolescents. METHODS: Cross-sectional data were collected from 301 students aged between 13 and 15 years (46.51% boys), enrolled at 7 secondary schools in the city of Huesca (Spain). Participants wore accelerometers during a 7-day period, and their academic achievement was calculated from the average marks of all subjects. Structural equation modeling and quadratic regression analysis were performed to test both linear and nonlinear explanatory models. One-way analysis of variance was also performed to explore the effect of gender and the percentage of compliance with MVPA recommendations. RESULTS: MVPA on weekdays and higher levels of body mass index were negatively associated with academic achievement. According to the curvilinear relationship, those students whose MVPA levels were closer to the daily recommendation were more likely to obtain higher academic achievement. However, a significant association was only shown in the case of boys. CONCLUSIONS: Adolescents who satisfy the international recommendations tend to obtain better academic achievement. Therefore, MVPA for adolescents should be prescribed within some beneficial time margins (50-70 min/d).

RBR-Type E3 Ligases and the Ubiquitin-Conjugating Enzyme UBC26 Regulate Abscisic Acid Receptor Levels and Signaling.

The turnover of abscisic acid (ABA) signaling core components modulates the plant's response to ABA and is regulated by ubiquitination. We show that Arabidopsis (Arabidopsis thaliana) RING Finger ABA-Related1 (RFA1) and RFA4 E3 ubiquitin ligases, members of the RING between RING fingers (RBR)-type RSL1/RFA family, are key regulators of ABA receptor stability in root and leaf tissues, targeting ABA receptors for degradation in different subcellular locations. RFA1 is localized both in the nucleus and cytosol, whereas RFA4 shows specific nuclear localization and promotes nuclear degradation of ABA receptors. Therefore, members of the RSL1/RFA family interact with ABA receptors at plasma membrane, cytosol, and nucleus, targeting them for degradation via the endosomal/vacuolar RSL1-dependent pathway or 26S proteasome. Additionally, we provide insight into the physiological function of the relatively unexplored plant RBR-type E3 ligases, and through mutagenesis and biochemical assays we identified cysteine-361 in RFA4 as the putative active site cysteine, which is a distinctive feature of RBR-type E3 ligases. Endogenous levels of PYR1 and PYL4 ABA receptors were higher in the rfa1 rfa4 double mutant than in wild-type plants. UBC26 was identified as the cognate nuclear E2 enzyme that interacts with the RFA4 E3 ligase and forms UBC26-RFA4-receptor complexes in nuclear speckles. Loss-of-function ubc26 alleles and the rfa1 rfa4 double mutant showed enhanced sensitivity to ABA and accumulation of ABA receptors compared with the wild type. Together, our results reveal a sophisticated mechanism by which ABA receptors are targeted by ubiquitin at different subcellular locations, in which the complexity of the ABA receptor family is mirrored in the partner RBR-type E3 ligases.

Improving Physical Activity Levels and Psychological Variables on University Students in the Contemplation Stage.

This study aimed to investigate the effects of a physical activity intervention, based on self-determination theory and the transtheoretical model, on university students in the contemplation stage. PARTICIPANTS: 42 students, in the contemplation stage at baseline, were randomly assigned to an experimental group (16 women, 2 men; M age = 19.1 ± 1.15) and a control group (18 women, 2 men; M age = 20.1 ± 5.7). METHODS: Physical activity was measured at different moments by accelerometry. Other cognitive variables were measured by self-reported scales. RESULTS: We did not find any significant increases in students' physical activity in favor of the intervention group. Intragroup analyses indicate that the intervention has an effect on physical activity (moderate-to-vigorous physical activity), basic psychological needs, and intrinsic and extrinsic motivation. CONCLUSIONS: Results partially demonstrate that applying social cognitive theories seems to be effective in improving physical activity and cognitive variables in university students in the contemplation stage.

Healthy or Unhealthy? The Cocktail of Health-Related Behavior Profiles in Spanish Adolescents.

The aim of this study was to identify the prevalence and clustering of health-related behaviors in Spanish adolescents and to examine their association with sex, body mass index (BMI), different types of sedentary screen time, and adherence to 24-hour movement guidelines. A final sample of 173 students (M = 12.99 ± 0.51) participated in this study. Cluster analysis was conducted based on five health-related behaviors: PA and sedentary time derived from accelerometers, as well as healthy diet, sedentary screen time, and sleep duration derived from self-reported scales. Recommendations for 24-hour movement guidelines (i.e., physical activity (PA), screen time, and sleep duration) were analyzed both independently and combined. A total of 8.9% of the sample did not meet any of the guidelines, whereas 72.3%, 17.3%, and 1.7% of the sample met 1, 2, or all 3 guidelines, respectively. Six distinct profiles were identified, most of them showing the co-occurrence of healthy- and unhealthy-related behaviors. Given that most of the adolescents failed to meet the combination of PA, screen time, and sleep duration guidelines, these findings suggest the necessity to implement school-based interventions that target multiple health behaviors, especially because (un)healthy behaviors do not always cluster in the same direction.

Does the Level of Motivation of Physical Education Teachers Matter in Terms of Job Satisfaction and Emotional Exhaustion? A Person-Centered Examination Based on Self-Determination Theory.

Grounded in self-determination theory (SDT), prior research has demonstrated that physical education (PE) teachers may have different reasons to engage in teaching. Although some person-centered studies have identified varied motivational profiles in PE teachers, none of these studies have included the three forms of motivation (i.e., autonomous motivation, controlled motivation, and amotivation). This study aims to identify teachers' motivational profiles, using the three forms of motivation. Moreover, differences between the obtained profiles in terms of job satisfaction and emotional exhaustion were examined. A sample of 107 primary school PE teachers participated. Four distinct motivational profiles were identified: "relatively amotivated," "somewhat motivated," "autonomous-controlled motivated," and "relatively autonomously motivated." Results showed that the predominantly autonomously motivated PE teachers reported the most adaptive pattern of outcomes. Although PE teachers from the "relatively autonomously motivated" group did not differ in terms of job satisfaction when compared to those in the "autonomous-controlled motivated" group, the former displayed lower values of emotional exhaustion. These findings support SDT in that more motivation is not necessarily better if this additional motivation comes from controlled reasons. These results could raise awareness among school stakeholders about the importance of increasing PE teachers' autonomous motivation.

The MATH-BTB BPM3 and BPM5 subunits of Cullin3-RING E3 ubiquitin ligases target PP2CA and other clade A PP2Cs for degradation.

Early abscisic acid signaling involves degradation of clade A protein phosphatases type 2C (PP2Cs) as a complementary mechanism to PYR/PYL/RCAR-mediated inhibition of PP2C activity. At later steps, ABA induces up-regulation of PP2C transcripts and protein levels as a negative feedback mechanism. Therefore, resetting of ABA signaling also requires PP2C degradation to avoid excessive ABA-induced accumulation of PP2Cs. It has been demonstrated that ABA induces the degradation of existing ABI1 and PP2CA through the PUB12/13 and RGLG1/5 E3 ligases, respectively. However, other unidentified E3 ligases are predicted to regulate protein stability of clade A PP2Cs as well. In this work, we identified BTB/POZ AND MATH DOMAIN proteins (BPMs), substrate adaptors of the multimeric cullin3 (CUL3)-RING-based E3 ligases (CRL3s), as PP2CA-interacting proteins. BPM3 and BPM5 interact in the nucleus with PP2CA as well as with ABI1, ABI2, and HAB1. BPM3 and BPM5 accelerate the turnover of PP2Cs in an ABA-dependent manner and their overexpression leads to enhanced ABA sensitivity, whereas bpm3 bpm5 plants show increased accumulation of PP2CA, ABI1 and HAB1, which leads to global diminished ABA sensitivity. Using biochemical and genetic assays, we demonstrated that ubiquitination of PP2CA depends on BPM function. Given the formation of receptor-ABA-phosphatase ternary complexes is markedly affected by the abundance of protein components and ABA concentration, we reveal that BPMs and multimeric CRL3 E3 ligases are important modulators of PP2C coreceptor levels to regulate early ABA signaling as well as the later desensitizing-resetting steps.

ABA inhibits myristoylation and induces shuttling of the RGLG1 E3 ligase to promote nuclear degradation of PP2CA.

Hormone- and stress-induced shuttling of signaling or regulatory proteins is an important cellular mechanism to modulate hormone signaling and cope with abiotic stress. Hormone-induced ubiquitination plays a crucial role to determine the half-life of key negative regulators of hormone signaling. For ABA signaling, the degradation of clade-A PP2Cs, such as PP2CA or ABI1, is a complementary mechanism to PYR/PYL/RCAR-mediated inhibition of PP2C activity. ABA promotes the degradation of PP2CA through the RGLG1 E3 ligase, although it is not known how ABA enhances the interaction of RGLG1 with PP2CA given that they are predominantly found in the plasma membrane and the nucleus, respectively. We demonstrate that ABA modifies the subcellular localization of RGLG1 and promotes nuclear interaction with PP2CA. We found RGLG1 is myristoylated in vivo, which facilitates its attachment to the plasma membrane. ABA inhibits the myristoylation of RGLG1 through the downregulation of N-myristoyltransferase 1 (NMT1) and promotes nuclear translocation of RGLG1 in a cycloheximide-insensitive manner. Enhanced nuclear recruitment of the E3 ligase was also promoted by increasing PP2CA protein levels and the formation of RGLG1-receptor-phosphatase complexes. We show that RGLG1Gly2Ala mutated at the N-terminal myristoylation site shows constitutive nuclear localization and causes an enhanced response to ABA and salt or osmotic stress. RGLG1/5 can interact with certain monomeric ABA receptors, which facilitates the formation of nuclear complexes such as RGLG1-PP2CA-PYL8. In summary, we provide evidence that an E3 ligase can dynamically relocalize in response to both ABA and increased levels of its target, which reveals a mechanism to explain how ABA enhances RGLG1-PP2CA interaction and hence PP2CA degradation.

PYL8 mediates ABA perception in the root through non-cell-autonomous and ligand-stabilization-based mechanisms.

The phytohormone abscisic acid (ABA) plays a key role regulating root growth, root system architecture, and root adaptive responses, such as hydrotropism. The molecular and cellular mechanisms that regulate the action of core ABA signaling components in roots are not fully understood. ABA is perceived through receptors from the PYR/PYL/RCAR family and PP2C coreceptors. PYL8/RCAR3 plays a nonredundant role in regulating primary and lateral root growth. Here we demonstrate that ABA specifically stabilizes PYL8 compared with other ABA receptors and induces accumulation of PYL8 in root nuclei. This requires ABA perception by PYL8 and leads to diminished ubiquitination of PYL8 in roots. The ABA agonist quinabactin, which promotes root ABA signaling through dimeric receptors, fails to stabilize the monomeric receptor PYL8. Moreover, a PYL8 mutant unable to bind ABA and inhibit PP2C is not stabilized by the ligand, whereas a PYL85KR mutant is more stable than PYL8 at endogenous ABA concentrations. The PYL8 transcript was detected in the epidermis and stele of the root meristem; however, the PYL8 protein was also detected in adjacent tissues. Expression of PYL8 driven by tissue-specific promoters revealed movement to adjacent tissues. Hence both inter- and intracellular trafficking of PYL8 appears to occur in the root apical meristem. Our findings reveal a non-cell-autonomous mechanism for hormone receptors and help explain the nonredundant role of PYL8-mediated root ABA signaling.

Effect of Recasting on Physical Properties of Base Metal Alloys: An In Vitro Study.

AIMS AND OBJECTIVES: This study aims to establish the outcome of recasting on tensile strength, modulus of elasticity, and hardness of Nickel-chromium alloys. MATERIALS AND METHODS: Fifty wax patterns were fabricated, using the lost wax technique, the measurements of which were standardized. They were categorized into five groups of ten each. Group I included samples casted with new alloy alone. Group II samples consisted of 75% new alloy and 25% once casted alloy. Group III was casted with 50% of each. Group IV with 25% new metal and 75% previous alloy and samples of Group V samples were casted with once casted alloy alone. Modulus of elasticity and tensile strength were measured by universal testing machine, whereas hardness using microhardness tester. The values were statistically analysed. IBM Corp. Released 2011. IBM SPSS Statistics for Windows, Version 20.0. IBM Corp, Armonk, NY, USA. for Windows software was used for analysis. RESULTS: We found a slight variation in mean tensile strength and modulus of elasticity, which was statistically insignificant variation among the groups. However, there was a significant difference in mean hardness between Groups III, IV, and V. CONCLUSION: It is prudent to use pure alloy alone for casting. However, in view of environment and economical factors, addition of <50% reused alloy to pure alloy is satisfactory clinically.

Ultrasonic evaluation of influence of hard acrylic resin denture on blood flow of mandibular denture supporting mucosa utilizing duplex color Doppler studies: An in vivo study.

AIMS: To determine the influence of hard acrylic denture base materials on the blood flow of mandibular denture supporting mucosa over a period of six months time. MATERIALS AND METHODS: Select fifteen edentulous patients of age 55-75 years. The blood flow of the mandibular denture supporting mucosa was measured bilaterally in the molar region and in the incisor region utilizing Ultrasound colour Doppler (2D and Duplex Imaging). Measurements were performed prior to denture insertion and later after the dentures were worn for 1 month, 2 months, 3 months, 4 months, 5 months and 6 months. STATISTICAL ANALYSIS USED: Mean blood flow as measured by Ultrasound colour Doppler were tabulated significant changes if any at various time interval in comparison to baseline was assessed by Kruskalwallis ANOVA test followed by Wilkoxan sign rank test for pairwise comparison. (In the present study, P < 0.05 was considered as the level of significance). RESULTS: The denture supporting mucosa exhibited a progressive reduction in the blood flow both with hard denture. The blood flow change with hard denture was a reversible condition as the blood flow improved at the end of six months. Kruskalwallis ANOVA test revealed no significant change in the blood flow at any interval of time in comparison to base value (P = 0.133). CONCLUSIONS: Within the limitations of the study denture supporting mucosa exhibited a progressive reduction in the blood flow with hard denture which was reversible.

Sedentary Behaviors by Type of Day and Physical Activity in Spanish Adolescents: A Socio-Ecological Approach.

The aim of this study was to analyze the relationship between TV and computer use, study time, and physical activity, with regard to gender, school, and weekday/weekend. Adolescents (N = 1,609; M age = 14.5 yr., SD = 1.3) reported on physical activity, sedentary behavior, their parents' employment, and environmental factors. The relationship between PA and screen media behaviors was negative on weekdays, while no relationship was found at weekends. Only 30.7% of adolescents met the screen media guidelines on weekdays and 14.6% at weekends. Girls spent more time on study, only showing a positive relationship with physical activity on weekdays. Each type of sedentary behavior has different correlates for weekdays and weekends.

Pseudooclusión carotídea sintomática: tratamiento quirúrgico y resultados / Symptomatic pseudo-occlusion of the carotid artery: surgical treatment and outcomes

Introducción. Estudios multicéntricos recientes sugieren un dudoso beneficio de la endarterectomía carotídea (EC) en pacientes con pseudooclusión carotídea (POC). Objetivo. Evaluar el resultado clínico y hemodinámico de la EC en las POC sintomáticas. Pacientes y métodos. Entre 1999 y 2005 se intervinieron 13 pacientes con POC interna (3,96% de la cirugía carotídea) sintomáticas: siete con infarto cerebral (53,8%), tres con accidente isquémico transitorio (23,1%), dos con amaurosis fugaz (15,4%) y uno con síncopes de repetición (7,7%). En todos se realizó eco-Doppler y angiografía. Criterios diagnósticos del eco-Doppler: oclusión origen carótida interna, flujo en goteo o señal distal amortiguada. Criterios diagnósticos de la angiografía: obstrucción origen carótida interna con relleno filiforme distal. Se indicó la revascularización quirúrgica en todos ellos. Resultados. En 12 pacientes se pudo revascularizar la carótida interna (92,3%) y en uno se hizo su ligadura (7,7%). Técnica de revascularización: 11 EC y un bypass a carótida interna distal. Morbimortalidad quirúrgica del 0%. Control clínico: 3-69 meses (media: 31,6 meses) mediante eco-Doppler de troncos supraaórticos y transcraneal, encontrándose todos vivos, asintomáticos y con permeabilidad de la carótida interna. La reserva hemodinámica homolateral postoperatoria se ha encontrado normalizada en la mayoría de los pacientes. Conclusiones. Se considera indicada la intervención quirúrgica en casos sintomáticos de POC, ya que logra la repermeabilización de la carótida y la normalización de la reserva hemodinámica en un alto porcentaje, previniendo además la aparición de nueva sintomatología a largo plazo

Introduction. Recent multicentre studies suggest dubious benefits for carotid endarterectomy (CE) in patients with pseudo-occlusion of the carotid artery (POC). Aim. To evaluate the clinical and haemodynamic outcomes of CE in cases of symptomatic POC. Patients and methods. Between 1999 and 2005 interventions were carried out on 13 patients with symptomatic pseudo-occlusion of the internal carotid artery (3.96% of the carotid surgery conducted): seven with cerebral infarction (53.8%), three with transient ischemic attack (23.1%), two with amaurosis fugax (15.4%) and one with recurring syncopes (7.7%). Doppler ultrasonography and angiography recordings were performed in all cases. Diagnostic criteria for Doppler ultrasonography were occlusion with its origin in the internal carotid artery, a drip flow or attenuated distal signals. Diagnostic criteria for angiography were occlusion with its origin in the internal carotid artery with filiform distal filling. Surgical revascularisation was indicated in all cases. Results. The internal carotid artery was revascularised in 12 patients (92.3%) and ligation was performed in one of them (7.7%). Revascularisation technique: 11 CE and one distal internal carotid artery bypass. Surgical morbidity and mortality rates of 0%. Clinical monitoring: 3-69 months (mean: 31.6 months) using transcranial and supra-aortic trunk Doppler ultrasonography; all patients were alive, asymptomatic and with patency of the internal carotid artery. The post-operative homolateral haemodynamic reserve was found to be at normal levels in most of the patients. Conclusions. Surgical intervention is considered to be indicated in symptomatic cases of POC, as it achieves repatency of the carotid artery and normalises the haemodynamic reserve in a high percentage of cases; it also prevents the appearance of new symptoms in the long term

Historia natural de los aneurismas de la aorta torácica / The natural history of thoracic aortic aneurysms

Introducción. La historia natural de los aneurismas de la aorta torácica (AAT) está escasamente documentada debido a la dificultad en el diagnóstico de pacientes asintomáticos con AAT y la falta de estudios de cribado en la población. Su evolución natural es el crecimiento progresivo que concluye en la ruptura, con elevada mortalidad. Desarrollo. Revisión sistemática de la bibliografía publicada en las bases de datos Medline y PubMed mediante las palabras clave indicadas al pie y en especial con la evaluación de los registros informatizados con bases de datos amplias de universidades o sociedades europeas y americanas de cirugía vascular, cardiovascular y torácica. Conclusiones. La supervivencia a cinco años de los pacientes con AAT no tratados es menor del 19%; la causa principal de muerte es la ruptura aneurismática. El tamaño es el factor fundamental de riesgo de ruptura. El riesgo de ruptura aumenta exponencialmente cuando el diámetro de la aorta ascendente supera los 6 cm y el de la aorta descendente los 7 cm, e igualmente cuando se producen crecimientos rápidos. La cirugía mejora la evolución natural de la enfermedad. La historia natural de los AAT está determinada por su tamaño y tasa de crecimiento. El principio de toma de decisiones en el tratamiento de estos enfermos ha de basarse en determinar el riesgo individualizado de complicaciones en su evolución natural (ruptura, disección) frente al riesgo de la corrección quirúrgica en la experiencia del grupo quirúrgico concreto. La cirugía endovascular ha supuesto ya un impacto positivo en la historia natural al permitir la corrección de AAT en pacientes de alto riesgo, sin otras posibilidades previas de tratamiento

Introduction. The literature on the natural history of thoracic aortic aneurysms (TAA) is scarce due to the difficulty involved in diagnosing asymptomatic patients with TAA and the lack of screening studies conducted in the population. Its natural history comprises a progressive growth that ends in rupture, with a high mortality rate. Development. We carried out a systematic search of the literature published in the Medline and PubMed databases using the key words indicated in the footnote below. Additionally and perhaps more important, we also evaluated the computer records in extensive databases from universities and European or American vascular, cardiovascular and thoracic surgery societies. Conclusions. The survival rate of untreated TAA patients at five years is lower than 19%, the main cause of death being aneurysmal rupture. Size is a fundamental factor associated to the risk of rupture. The risk of rupture increases exponentially when the diameter of the ascending aorta exceeds 6 cm and that of the descending aorta goes beyond 7 cm; this is also the true when rapid growth takes place. Surgery improves the natural history of the disease. The natural history of TAAs is determined by their size and growth rate. The principle guiding decision-making in the treatment of these patients must be based on determining the individual risk of complications in their natural history (rupture, dissection) versus the risk involved in surgical correction, according to the experience of each particular surgical group. Endovascular surgery has had a positive effect on the natural history by allowing TAA to be corrected in high-risk patients who previously had no other chances of treatment open to them