Early recognition of SGCE-myoclonus-dystonia in children.

AIM: To evaluate early dystonic features in children and adolescents with SGCE-myoclonus-dystonia. METHOD: In this cross-sectional study, 49 patients (26 females and 23 males) with SGCE-myoclonus-dystonia (aged 15y 2mo, SD 12y) with childhood-onset (2y 10mo, SD 1y 10mo) dystonia were examined using a standardized video recorded protocol. Dystonia was rated using the Writer's Cramp and Gait Dystonia Rating Scales. Disability and impairment for handwriting and walking were also rated. RESULTS: Dystonia was present at rest (n=1), posture (n=12), and during specific motor tasks (n=45) such as writing (n=35), walking (n=23), and running (n=20). Most children reported disability while performing these tasks. Early dystonic patterns were identified for writer's cramp and gait dystonia, the latter named the 'circular shaking leg', 'dragging leg', and 'hobby-horse gait' patterns. Sensory tricks were used by five and eight children to improve dystonia and myoclonus during writing and walking respectively. The rating scales accurately measured the severity of action dystonia and correlated with self-reported disability. INTERPRETATION: Children with SGCE-myoclonus-dystonia show recognizable dystonic patterns and sensory tricks that may lead to an early diagnosis and timely therapeutic approach. Isolated writer's cramp is a key feature in childhood and should prompt SCGE analysis. The proposed action dystonia scales could be used to monitor disease course and response to treatment. WHAT THIS PAPER ADDS: Most children with SGCE-myoclonus-dystonia got writer's cramp and had walking and running dystonia. Writer's cramp was a key feature and should prompt SGCE genetic investigation. 'Circular shaking leg', 'dragging leg', and 'hobby-horse gait' were recognized as early gait patterns. Children used sensory tricks to improve myoclonus and dystonia, suggesting common pathophysiological mechanisms. Action dystonia rating scales are valid tools to assess severity in children.

Efficacy and safety of onasemnogene abeparvovec in children with spinal muscular atrophy type 1: real-world evidence from 6 infusion centres in the United Kingdom.

Background: Real-world data on the efficacy and safety of onasemnogene abeparvovec (OA) in spinal muscular atrophy (SMA) are needed, especially to overcome uncertainties around its use in older and heavier children. This study evaluated the efficacy and safety of OA in patients with SMA type 1 in the UK, including patients ≥2 years old and weighing ≥13.5 kg. Methods: This observational cohort study used data from patients with genetically confirmed SMA type 1 treated with OA between May 2021 and January 2023, at 6 infusion centres in the United Kingdom. Functional outcomes were assessed using age-appropriate functional scales. Safety analyses included review of liver function, platelet count, cardiac assessments, and steroid requirements. Findings: Ninety-nine patients (45 SMA therapy-naïve) were treated with OA (median age at infusion: 10 [range, 0.6-89] months; median weight: 7.86 [range, 3.2-20.2] kg; duration of follow-up: 3-22 months). After OA infusion, mean ± SD change in CHOP-INTEND score was 11.0 ± 10.3 with increased score in 66/78 patients (84.6%); patients aged <6 months had a 13.9 points higher gain in CHOP-INTEND score than patients ≥2 years (95% CI, 6.8-21.0; P < 0.001). Asymptomatic thrombocytopenia (71/99 patients; 71.7%), asymptomatic troponin-I elevation (30/89 patients; 33.7%) and transaminitis (87/99 patients; 87.9%) were reported. No thrombotic microangiopathy was observed. Median steroid treatment duration was 97 (range, 28-548) days with dose doubled in 35/99 patients (35.4%). There were 22.5-fold increased odds of having a transaminase peak >100 U/L (95% CI, 2.3-223.7; P = 0.008) and 21.2-fold increased odds of steroid doubling, as per treatment protocol (95% CI, 2.2-209.2; P = 0.009) in patients weighing ≥13.5 kg versus <8.5 kg. Weight at infusion was positively correlated with steroid treatment duration (r = 0.43; P < 0.001). Worsening transaminitis, despite doubling of oral prednisolone, led to treatment with intravenous methylprednisolone in 5 children. Steroid-sparing immunosuppressants were used in 5 children to enable steroid weaning. Two deaths apparently unrelated to OA were reported. Interpretation: OA led to functional improvements and was well tolerated with no persistent clinical complications, including in older and heavier patients. Funding: Novartis Innovative Therapies AG provided a grant for independent medical writing services.

Recurrent atraumatic compartment syndrome as a manifestation of genetic neuromuscular disease.

Compartment syndrome (CS) is a medical emergency that occurs secondary to excessively high pressures within a confined fibro-osseous space, resulting in reduced perfusion and subsequent tissue injury. CS can be divided into acute forms, most commonly due to trauma and considered an orthopaedic emergency, and chronic forms, most commonly presenting in athletes with recurrent exercise-induced pain. Downstream pathophysiological mechanisms are complex but do share commonalities with mechanisms implicated in genetic neuromuscular disorders. Here we present 3 patients with recurrent CS in the context of a RYR1-related disorder (n = 1) and PYGM-related McArdle disease (n = 2), two of whom presented many years before the diagnosis of an underlying neuromuscular disorder was suspected. We also summarize the literature on previously published cases with CS in the context of a genetically confirmed neuromuscular disorder and outline how the calcium signalling alterations in RYR1-related disorders and the metabolic abnormalities in McArdle disease may feed into CS-causative mechanisms. These findings expand the phenotypical spectrum of RYR1-related disorders and McArdle disease; whilst most forms of recurrent CS will be sporadic, above and other genetic backgrounds ought to be considered in particular in patients where other suggestive clinical features are present.

ε-Sarcoglycan: Unraveling the Myoclonus-Dystonia Gene.

Myoclonus-dystonia (MD) is a rare childhood-onset movement disorder, with an estimated prevalence of about 2 per 1,000,.000 in Europe, characterized by myoclonic jerks in combination with focal or segmental dystonia. Pathogenic variants in the gene encoding ε-sarcoglycan (SGCE), a maternally imprinted gene, are the most frequent genetic cause of MD. To date, the exact role of ε-sarcoglycan and the pathogenic mechanisms that lead to MD are still unknown. However, there are more than 40 reported isoforms of human ε-sarcoglycan, pointing to a complex biology of this protein. Additionally, some of these are brain-specific isoforms, which may suggest an important role within the central nervous system. In the present review, we aim to provide an overview of the current state of knowledge of ε-sarcoglycan. We will focus on the genetic landscape of SGCE and the presence and plausible role of ε-sarcoglycan in the brain. Finally, we discuss the importance of the brain-specific isoforms and hypothesize that SGCE may play essential roles in normal synaptic functioning and their alteration will be strongly related to MD.

Delineating the motor phenotype of SGCE-myoclonus dystonia syndrome.

OBJECTIVE: To perform phenotype and genotype characterization in myoclonus-dystonia patients and to validate clinical rating tools. METHOD: Two movement disorders experts rated patients with the Burke-Fahn-Marsden and Unified-Myoclonus rating scales using a video-recording protocol. Clinimetric analysis was performed. SGCE mutations were screened by Sanger sequencing and multiplex ligation-dependent probe amplification. RESULTS: 48 patients were included and 43/48 rated. Mean age at assessment was 12.9±10.5 years (range 3-51) and 88% were ≤18 years of age. Myoclonus was a universal sign with a rostro-caudal severity-gradient. Myoclonus increased in severity and spread to lower limbs during action tests. Stimulus-evoked myoclonus was observed in 86.8% cases. Dystonia was common but mild. It had a focal distribution and was action-induced, causing writer's cramp (69%) and gait dystonia (34%). The severity of both myoclonus and dystonia had a strong impact on hand writing and walking difficulties. The Unified Myoclonus Rating scale showed the best clinimetric properties for the questionnaire, action myoclonus and functional subscales, and exceeded the Burke-Fahn-Marsden scale in its utility in assessing functional impairment in MDS patients. Twenty-one different SGCE mutations were identified in 45/48 patients, eleven being novel (most prevalent p. Val187*, founder mutation in Canary Islands). CONCLUSION: This study quantifies the severity of the motor phenotype in SGCE-myoclonus dystonia syndrome, with a special focus on children, and identifies disabilities in gross and fine motor tasks that are essential for childhood development. Our results contribute to the knowledge of SGCE-related MDS in the early stage of evolution, where disease-modifying therapies could be initiated in order to prevent long-term social and physical burdens.

Pancreatic ß-cell dysfunction in normoglycemic patients and risk factors.

AIMS: To evaluate pancreatic ß-cell function (ßf) in patients with normoglycemia (NG) and normal glucose tolerance (NGT) and related risk factors. METHODS: An observational and comparative study in 527 patients with NG and NGT that were divided by quartiles of ßf according to the disposition index derived from OGTT. Anthropometrical, clinical, nutritional, and biochemical variables were measured and associated with ßf. RESULTS: Quartiles of ßf were Q1 = DI < 1.93 n = 131, Q2 = DI 1.93-2.45 n = 134, Q3 = DI 2.46-3.1 n = 133, and Q4 = DI > 3.1 n = 129. There was a progressive reduction in pancreatic ß-cell function and it is negatively correlated with age, weight, BMI, total body fat and visceral fat, waist circumference, total cholesterol, LDL, and triglycerides (p < 0.01). Glucose levels during OGTT had a negative correlation with ßf; the product of fasting glucose by 1-h glucose had the best correlation with ßf (r = 0.611, p < 0.001) and was the best predictor of ßdf (AUC 0.816, CI 95% 0.774-0.857), even better than 1-h glucose (r = 0.581, p < 0.001). Energy, fat, and carbohydrate intake were negatively correlated with ßf (p < 0.05). Glucose levels at 1-h OGTT > 110 mg/dl were positively associated with pancreatic ßdf (OR 6.85, CI 95% 3.86-12.4). In the multivariate analysis, glucose levels during OGTT, fasting insulin, and BMI were the main factors associated with ßf. CONCLUSIONS: A subgroup of patients with NG and NGT may have a loss of 40% of their ßf. Factors related to this ßdf were age, adiposity, glucose during OGTT, and the product of fasting and 1-h glucose, as well as food intake.

Frameless robot-assisted pallidal deep brain stimulation surgery in pediatric patients with movement disorders: precision and short-term clinical results.

OBJECTIVE: The purpose of this study was to verify the safety and accuracy of the Neuromate stereotactic robot for use in deep brain stimulation (DBS) electrode implantation for the treatment of hyperkinetic movement disorders in childhood and describe the authors' initial clinical results. METHODS: A prospective evaluation of pediatric patients with dystonia and other hyperkinetic movement disorders was carried out during the 1st year after the start-up of a pediatric DBS unit in Barcelona. Electrodes were implanted bilaterally in the globus pallidus internus (GPi) using the Neuromate robot without the stereotactic frame. The authors calculated the distances between the electrodes and their respective planned trajectories, merging the postoperative CT with the preoperative plan using VoXim software. Clinical outcome was monitored using validated scales for dystonia and myoclonus preoperatively and at 1 month and 6 months postoperatively and by means of a quality-of-life questionnaire for children, administered before surgery and at 6 months' follow-up. We also recorded complications derived from the implantation technique, "hardware," and stimulation. RESULTS: Six patients aged 7 to 16 years and diagnosed with isolated dystonia ( DYT1 negative) (3 patients), choreo-dystonia related to PDE2A mutation (1 patient), or myoclonus-dystonia syndrome SGCE mutations (2 patients) were evaluated during a period of 6 to 19 months. The average accuracy in the placement of the electrodes was 1.24 mm at the target point. At the 6-month follow-up, patients showed an improvement in the motor (65%) and functional (48%) components of the Burke-Fahn-Marsden Dystonia Rating Scale. Patients with myoclonus and SGCE mutations also showed an improvement in action myoclonus (95%-100%) and in functional tests (50%-75%) according to the Unified Motor-Rating Scale. The Neuro-QOL score revealed inconsistent results, with improvement in motor function and social relationships but worsening in anxiety, cognitive function, and pain. The only surgical complication was medial displacement of the first electrode, which limited intensity of stimulation in the lower contacts, in one case. CONCLUSIONS: The Neuromate stereotactic robot is an accurate and safe tool for the placement of GPi electrodes in children with hyperkinetic movement disorders.

Identification and characterization of the chromatin-binding domains of the HIV-1 integrase interactor LEDGF/p75.

Depletion of the transcriptional co-activator LEDGF/p75 by RNA interference alters the genome-wide pattern of HIV-1 integration, reducing integration into active genes, reducing integration into LEDGF/p75-regulated genes, and increasing integration into G+C-rich sequences. LEDGF/p75 is also able to act as a molecular tether linking HIV-1 integrase protein to chromatin, a phenomenon likely to underlie the integration site distribution effects. The LEDGF/p75 integrase-binding domain has been established but the domain or domains responsible for the chromatin-binding component of tethering are unknown. Here, we identify and characterize these domains. Complementary methods were used to assess condensed and uncondensed chromatin, and to determine the stringency of chromatin binding. Immuno-localization analyses revealed that an N-terminal PWWP domain and its beta-barrel substructure are needed for binding to metaphase chromatin. However, the PWWP domain is insufficient to transfer metaphase chromatin binding to green fluorescent protein, which requires addition of a downstream charged region (CR1). Biochemical analysis showed that full-length LEDGF/p75 resists Triton X-100 extraction from chromatin. To transfer Triton-resistant chromatin binding to green fluorescent protein, PWWP-CR1 is necessary but not sufficient. Further inclusion of a tandem pair of AT-hooks in combination with at least one of two identified downstream charged regions (CR2 or CR3) is needed. Deletion of just the PWWP or the AT-hook domain from full-length LEDGF/p75 reduced Triton-resistant chromatin binding, while deletion of both elements abolished it, underscoring their dominant and cooperative role. The results establish a molecular mechanism for LEDGF/p75-mediated tethering of HIV-1 integrase to chromatin.

Characterization of Shiga toxigenic Escherichia coli isolated from foods.

The aim of this study was to characterize Shiga toxigenic Escherichia coli (STEC) by PCR using strains isolated from ham, beef, and cattle in Colombia. A total of 189 E. coli strains were tested for the presence of the uidA, stx1, and stx2 genes, and identification was confirmed by the automated PCR BAX system for E. coli O157:H7. Genes encoding Shiga-like toxins (stx) were found in eight (6.06%) of 132 strains previously isolated from minced beef; four (50%) of these strains yielded amplification products for both toxin genes (stx1 and stx2), and four (50%) yielded products only for the stx2 toxin. None of the strains analyzed were positive by PCR for the presence of the single base-pair mutation in the uidA gene from E. coli O157:H7; these results were confirmed by the BAX system analysis. A multiplex PCR assay was standardized for the three genes. Results from this study confirmed previous data about the low prevalence of E. coli O157:H7 and Shiga-like toxins in Colombia and is the first known report of the prevalence of non-O157 enterohemorrhagic E. coli in this country.

Impact on Hip Fracture Mortality After the Establishment of an Orthogeriatric Care Program in a Colombian Hospital.

OBJECTIVE: The aim of this study is to evaluate mortality and survival rates of patients aged 65 years or older who sustained a hip fracture and were treated at a hospital in Bogotá, Colombia, after the establishment of an Orthogeriatric Program. METHOD: In total, 298 patients were treated according to the program's protocol. The primary outcome was 1-year mortality. Mortality predictors were estimated using Cox proportional hazards model, and survival was measured with Kaplan-Meier analysis. RESULTS: The annual survival rate increased from 80% to 89% ( p = .039) 4 years after its implementation. There was a significant decrease in mortality risk (Hazard Ratio = 0.54, p = .049). Arrhythmia, valvular heart disease, history of myocardial infarction, and age greater than 85 years were predictors of mortality. DISCUSSION: This is the first study in Latin America to show decreased mortality rates 1 year after the implementation of an Orthogeriatric Program. Our rates were lower than developed countries, suggesting the existence of additional factors that influence long-term outcomes.

[Molecular typing of Listeria monocytogenes isolated from clinical and food samples]. / Tipificación molecular de Listeria monocytogenes aisladas de muestras clínicas y alimentos.

INTRODUCTION: Listeria monocytogenes is an emergent foodborne pathogen acquired by the ingestion of contaminated food. This bacterium causes a disease called listeriosis, whose mortality rate world wide is around 20% to 30%, reaching up to 80% in cases of neonatal infections. The random amplified polymorphic DNA technique allows different isolates to be distinguished and characterized at the molecular level, which can provide useful information about the diversity of this pathogen in Colombia. OBJECTIVE: To molecularly characterize different L. monocytogenes isolates from food and clinical samples using this technique to determine possible relationships among these two origins. MATERIALS AND METHODS: Thirty eight L. monocytogenes isolates were analyzed; 22 from human clinical samples and 16 from food processing plants and food using two 10bp primers (HLW74, Arbitrary). The data were analyzed using Quantity One and SYN-TAX software. RESULTS: A high percentage of polymorphism was detected with both primers (HLWL-74, 81.81%; Arbitrary, 85.71%). Two major lineages were found, which were divided into four major clusters (A, B C and D) and great genetic diversity was observed. Most of the clinical isolates were grouped within the same cluster, and were more distantly related to the food isolates. CONCLUSION: The results of this study demonstrate a high degree of genetic diversity of DNA polymorphisms among the L. monocytogenes isolates circulating in Colombia, which could reflect phenotypic and pathogenic differences in these isolates.

La técnica de perfilación criminológica: conocimiento, características y utilidad en Colombia / The Criminal Profiling Technique: Knowledge, Characteristics and Usefulness in Colombia / A técnica do perfil criminológico: conhecimento, característica e utilidade na Colômbia

Resumen La presente investigación tuvo como objetivo indagar sobre el conocimiento, las características y la utilidad de la técnica de perfilación criminológica dentro de una muestra de actores judiciales en Colombia, quienes, por sus funciones profesionales en la investigación criminal, se encontraban en posibilidad de aplicar la técnica. La metodología incluyó la realización de entrevistas semiestructuradas a 155 funcionarios pertenecientes a las principales instituciones de administración de justicia colombiana (Fiscalía, Policía Nacional, Defensoría del Pueblo, Instituto Nacional Penitenciario y Carcelario, y miembros de la rama judicial). Entre los resultados se encuentra que los actores judiciales consideran útil la técnica por la noción de cientificidad que tienen sobre ella. Asimismo, aunque se percibe útil, es poco usada debido al desconocimiento general derivado del poco entrenamiento recibido para su ejecución. Estos resultados se discuten frente a la historia reciente del estudio en materia criminológica en el país, la formación de sus profesionales y las brechas entre la investigación académica y su uso en la práctica de investigación criminal. Se concluye que la técnica en el contexto colombiano está aún en desarrollo, actualmente cuenta con algunas guías y protocolos al interior de cada institución y requiere de mayores ejercicios de evaluación de impacto y análisis exhaustivos de su relevancia y cientificidad.

Abstract This research study's objective was to explore the knowledge, characteristics and usefulness of the criminal profiling technique within a sample of judicial actors in Colombia who, due to their professional functions in criminal investigations, could possibly apply the technique. The methodology included performing semi-structured interviews on 155 officials belonging to Colombia's main institutions for the administration of justice (Prosecutor's Office, National Police, Ombudsman's Office, National Penitentiary and Prison Institute, and members of the judicial branch). Among the results, it was observed that judicial actors consider the technique useful due to the scientific notion they have regarding it. Furthermore, although it is perceived as being useful, it is seldom used because of a general lack of knowledge derived from scant training for its execution. These results are discussed in light of the recent criminological study carried out in the country, its professionals' education and the gaps in academic research and its use in criminal investigations. It was concluded that the technique is still being developed in the Colombian context. It currently have some guides and protocols within each institution, and requires more impact assessments and comprehensive analyses regarding its relevance and scientific nature.

Resumo O objetivo desta pesquisa foi indagar sobre o conhecimento, as características e a utilidade da técnica de perfil criminológico dentro de uma amostra de atores judiciais na Colômbia que, devido às suas funções profissionais na investigação criminal, são capazes de aplicar a técnica. A metodologia incluiu a realização de entrevistas semiestruturadas com 155 funcionários pertencentes às principais instituições de administração de justiça colombiana (Procuradoria, Polícia Nacional, Defensoria do povo, Instituto Nacional Penitenciário e Carcerário, e membros do poder judiciário). Entre os resultados, encontra-se que os atores judiciais consideram a técnica útil devido à noção de cientificidade que possuem sobre ela. Da mesma forma, embora seja percebida como útil, é pouco utilizada por causa do desconhecimento geral derivado do pouco treinamento recebido para sua execução. Esses resultados são discutidos à luz da história recente do estudo da criminologia no país, da formação de seus profissionais e as brechas entre a pesquisa acadêmica e sua utilização na prática da investigação criminal. Conclui-se que a técnica, no contexto colombiano, ainda está em desenvolvimento. Atualmente possui alguns guias e protocolos dentro de cada instituição e requer maiores exercícios de avaliação de impacto e análise exaustiva de sua relevância e cientificidade.

Comparison of total intravenous anesthesia and sevoflurane-fentanyl anesthesia for outpatient otorhinolaryngeal surgery.

STUDY OBJECTIVE: To compare the recovery characteristics of two widely used anesthetic techniques: remifentanyl-propofol and sevoflurane-fentanyl in a standardized ambulatory population. DESIGN: Randomized, single-blinded study. SETTING: University-affiliated medical center. PATIENTS: 50 ASA physical status I and II patients undergoing elective ambulatory otorhinolaryngeal surgery. INTERVENTIONS: Patients were randomized two groups to receive total intravenous anesthesia (TIVA group) with remifentanil and propofol or sevoflurane-fentanyl (SF group). TIVA patients received induction with propofol 1.5 mg/kg intravenously (IV) and remifentanil 0.5 microg/kg IV. The anesthesia was continued with a continuous infusion of propofol 100 microg/kg/min and remifentanil 0.0625-0.25 microg/kg/min. The SF group received, at induction, fentanyl 2 microg/kg followed by propofol 1.5 mg/kg IV. Maintenance was obtained with 1 to 1.5 minimum alveolar concentration of sevoflurane and bolus of fentanyl 1 microg/kg IV as needed. MEASUREMENTS AND MAIN RESULTS: Early recovery times (eye opening, response to commands, extubation, orientation, operating room stay after surgery, and Aldrete score > or =9) and patient satisfaction were similar between the two groups. Postanesthetic discharge scoring system (PADSS) > or = 9 was significantly shorter for the TIVA group (135.9 +/- 51 vs. 103 +/- 32 min) (p < 0.01) but this difference was not associated with a shorter postanesthesia care unit (PACU) length of stay. CONCLUSION: Early recovery times are comparable between total intravenous anesthesia and sevoflurane-based anesthesia. Even though patients in the TIVA group achieved home readiness criteria in a significantly shorter time, this technique does not shorten PACU length of stay, which depends instead on multiple nonmedical and administrative issues.

Nueva unidad de oncología infantil / New children's oncology unit

La humanización de los servicios de salud es la apuesta más importante que están desarrollando diferentes centros asistenciales en el país, lograr que el paciente y su familia se sientan más y mejor atendidos es todo un reto. Es así como el Hospital Infantil Universitario de San José cumpliendo con su promesa de valor "manos cálidas y confiables" renovó su unidad de oncología infantil convirtiéndola en un ambiente más agradable para los niños que atiende la institución. Este hospital era el antiguo Lorencita Villegas de Santos y fue rescatado en el año 2006 por la Fundación Universitaria de Ciencias de la Salud (FUCS) con 11 años de reapertura. Es conocido como el moderno Hospital Infantil Universitario de San José. La FUCS ha velado por su Institución y es así como gracias a su aporte económico y al de Asociados y Vélez, tras dos meses de remodelación, esta ala oncológica hoy es un hecho. Los niños tendrán un espacio más cómodo para ellos y sus acompañantes, en el que se sientan con un mejor estado de ánimo para afrontar sus procedimientos y recuperación. Es de resaltar que una quimioterapia puede tomar hasta seis u ocho horas diarias, lo cual genera un desgaste físico y mental que debe ser afrontado de la mejor manera.

Molecular characterization of diarrheagenic Escherichia coli strains from stools samples and food products in Colombia.

The prevalence of diarrheagenic Escherichia coli in childhood diarrhea and the role of contaminated food products in disease transmission in Colombia are largely unknown. The aim of this study is to identify E. coli pathotypes, including E. coli O157:H7, from 108 stool samples from children with acute diarrhea, 38 meat samples and 38 vegetable samples. Multiplex PCR and Bax Dupont systems were used for E. coli pathotype detection. Eighteen (9.8%) E. coli diarrheagenic pathotypes were detected among all clinical and food product samples tested. Four different pathotypes were identified from clinical samples, including enteroaggregative E. coli, enterotoxigenic E. coli, shiga-toxin producing E. coli, and enteropathogenic E. coli. Food product samples were positive for enteroaggregative and shiga-toxin producing E. coli, suggesting that meat and vegetables may be involved in transmission of these E. coli pathotypes in the community. Most E. coli strains identified belong to the phylogenetic groups A and B1, known to be associated with intestinal rather than extraintestinal E. coli clones. Our data is the first molecular E. coli report that confirms the presence of E. coli pathotypes circulating in Colombia among children with diarrhea and food products for human consumption. Implementation of multiplex PCR technology in Latin America and other countries with limited resources may provide an important epidemiological tool for the surveillance of E. coli pathotypes from clinical isolates as well as from water and food product samples.

Fatal outcome of a young woman with papillary thyroid carcinoma and graves' disease: possible implication of "cross-signalling" mechanism.

A 29 yrs-old patient was referred to our hospital due to generalized convulsions. She had hyperthyroidism treated with methimazole. Her MRI showed 4 metastatic lesions in the brain. She had a goiter with a "cold" nodule and a palpable ipsilateral lymph node. The FNAB disclosed a papillary thyroid carcinoma. Under 5 mg of MMI treatment, she had a subclinical hyperthyroidism and TRAb were 47.8% (n.v. < 10%). The CT scan also showed lung metastasis. She underwent a total thyroidectomy with a modified neck dissection and she received an accumulated radioiodine dose of 700 mCi during the following two years. She died from the consequences of multiple metastatic lesions. Studies were performed in DNA extracted from paraffin-embedded tissue from the tumor, the metastatic lymph node and the non-tumoral thyroid. The genetic analysis of tumoral DNA revealed point mutations in two different genes: the wild type CAA at codon 61 of N-RAS mutated to CAT, replacing glycine by histidine (G61H) and the normal GCC sequence at codon 623 of the TSHR gene was replaced by TCC, changing the alanine by serine (A623S). In the non-tumoral tissue no mutations were found. In vitro studies showed a constitutive activation of the TSHR. It is very probable that this activating mutation of the TSHR is unable to reach the end point of the PKA cascade in the tumoral tissue. One possibility that could explain this is the presence of a cross-signaling mechanism generating a deviation of the TSH receptor cascade to the more proliferative one involving the MAPKinase, giving perhaps a more aggressive behavior of this papillary thyroid cancer.

Serotipificación molecular e identificación del fragmento 85M deaislamientos colombianos de Listeria monocytogenes: Un estudio descriptivo / Molecular serotyping and identification of the 85M gragment in different Colombian isolates of Listeria monocytogenes strains: A descriptive study

Introduction: Listeria monocytogenes is a pathogen acquired through the consumption of contaminated foods.Thirteen serotypes have been reported, of which 1/2a, 1/2b, and 4b are responsible for 98% of human listeriosis cases. This study examines the association between serotypes and virulent clones, offering greater information and providingtools to prevent and control diseases caused by L. monocytogenes serotype 4b. Objective: To identify the serotypes from L. monocytogene strains isolated from different samples by performingthe molecular subtyping technique; to determine the 85M fragment that codifies for epidemic clone I.Methods : 108 strains of L. monocytogenes were used, isolated from samples of animals, body fluids, foods, and food processing plant equipment and spaces. The samples were identified by following the Bacteriological AnalyticalManual protocol described by the Food and Drug Administration (FDA). The strains were identified by PolymeraseChain Reaction (PCR) using primers and a standardized protocol from a previous research project. Serotypeidentification was performed by multiplex PCR. The determination of the 85M fragment of the SSCS cassette was done by following the protocol by Yildrim et al. Results : Of the 108 L. monocytogenes strains analyzed, 60.2% (65 strains) belonged to the 4b-4d-4e serotype, 17.6%(19 strains) were identified as 1/2a-3a serotype, 14.8% (16 strains) were 4a-4c serotype, 3.7% (4 strains) belonged to the 1/2c-3c serotype, and (3.7%) corresponded to the 1/2b-3b-7 serotype. It was determined that the L. monocytogenes strains serotype 4b-4d-4e and 1/2a-3b have the 85M fragment of the SSCS cassette.Conclusion : This study reports the predominant existence of L. monocytogenes strains serotype 4b-4d-4e in food, environmental, and clinical samples. The presence of an epidemic clone I region was also found in L. monocytogenes strains.

Identification of the LEDGF/p75 HIV-1 integrase-interaction domain and NLS reveals NLS-independent chromatin tethering.

To investigate the basis for the LEDGF/p75 dependence of HIV-1 integrase (IN) nuclear localization and chromatin association, we used cell lines made stably deficient in endogenous LEDGF/p75 by RNAi to analyze determinants of its location in cells and its ability to interact with IN. Deletion of C-terminal LEDGF/p75 residues 340-417 preserved nuclear and chromatin localization but abolished the interaction with IN and the tethering of IN to chromatin. Transfer of this IN-binding domain (IBD) was sufficient to confer HIV-1 IN interaction to GFP. HRP-2, the only other human protein with an identifiable IBD domain, was found to translocate IN to the nucleus of LEDGF/p75(-) cells. However, in contrast to LEDGF/p75, HRP-2 is not chromatin bound and does not tether IN to chromatin. A single classical nuclear localization signal (NLS) in the LEDGF/p75 N-terminal region ((146)RRGRKRKAEKQ(156)) was found by deletion mapping and was shown to be transferable to pyruvate kinase. Four central basic residues in the NLS are critical for its activity. Strikingly, however, stable expression studies with NLS(+/-) and IBD(+/-) mutants revealed that the NLS, although responsible for LEDGF/p75 nuclear import, is dispensable for stable, constitutive nuclear association of LEDGF/p75 and IN. Both wild-type LEDGF/p75 and NLS-mutant LEDGF/p75 remain entirely chromatin associated throughout the cell cycle, and each tethers IN to chromatin. Thus, these experiments reveal stable nuclear sequestration of a transcriptional regulator by chromatin during the nuclear-cytosolic mixing of cell division, which additionally enables stable tethering of IN to chromatin. LEDGF/p75 is a multidomain adaptor protein that interacts with the nuclear import apparatus, lentiviral IN proteins and chromatin by means of an NLS, an IBD and additional chromatin-interacting domains.

Lens epithelium-derived growth factor/p75 prevents proteasomal degradation of HIV-1 integrase.

The transcriptional coactivator lens epithelium-derived growth factor (LEDGF)/p75 acts as a chromatin tethering factor for human immunodeficiency virus type 1 (HIV-1) integrase protein, determining its nuclear localization and its tight association with nuclear DNA. Here we identify a second function for the LEDGF/p75-integrase interaction. We observed that stable introduction of HIV-1 integrase (IN) transcription units into cells made stringently LEDGF/p75-deficient by RNAi resulted in much lower steady state levels of IN protein than introduction into LEDGF/p75 wild type cells. The same LEDGF/p75-dependent disparity was observed for feline immunodeficiency virus IN. However, IN mRNA levels were equivalent in the presence and absence of LEDGF/p75. A post-translational mechanism was confirmed when the half-life of HIV-1 IN protein was found to be much shorter in LEDGF/p75-deficient cells. Proteasome inhibition fully countered this extreme instability, increasing IN protein levels to those seen in LEDGF/p75 wild type cells and implicating proteasomal destruction as the main cause of IN instability. Consistent with these data, increased ubiquitinated HIV-1 IN was found in the LEDGF/p75 knock-down cells. Moreover, restoration of LEDGF/p75 to knocked down clones rescued HIV-1 IN stability. Subcellular fractionation showed that HIV-1 IN is exclusively cytoplasmic in LEDGF/p75-deficient cells, but mainly nuclear in LEDGF/p75 wild type cells, and that cytoplasmic HIV-1 IN has a shorter half-life than nuclear HIV-1 IN. However, using LEDGF proteins defective for nuclear localization and IN interaction, we further determined that protection of HIV-1 IN from the proteasome requires neither chromatin tethering nor nuclear residence. Protection requires only interaction with LEDGF/p75, and it is independent of the subcellular localization of the IN-LEDGF complex.