Enhancing prime editing in hematopoietic stem and progenitor cells by modulating nucleotide metabolism.

Therapeutic prime editing of hematopoietic stem and progenitor cells (HSPCs) holds great potential to remedy blood disorders. Quiescent cells have low nucleotide levels and resist retroviral infection, and it is possible that nucleotide metabolism could limit reverse transcription-mediated prime editing in HSPCs. We demonstrate that deoxynucleoside supplementation and Vpx-mediated degradation of SAMHD1 improve prime editing efficiency in HSPCs, especially when coupled with editing approaches that evade mismatch repair.

Epitope editing enables targeted immunotherapy of acute myeloid leukaemia.

Despite the considerable efficacy observed when targeting a dispensable lineage antigen, such as CD19 in B cell acute lymphoblastic leukaemia1,2, the broader applicability of adoptive immunotherapies is hampered by the absence of tumour-restricted antigens3-5. Acute myeloid leukaemia immunotherapies target genes expressed by haematopoietic stem/progenitor cells (HSPCs) or differentiated myeloid cells, resulting in intolerable on-target/off-tumour toxicity. Here we show that epitope engineering of donor HSPCs used for bone marrow transplantation endows haematopoietic lineages with selective resistance to chimeric antigen receptor (CAR) T cells or monoclonal antibodies, without affecting protein function or regulation. This strategy enables the targeting of genes that are essential for leukaemia survival regardless of shared expression on HSPCs, reducing the risk of tumour immune escape. By performing epitope mapping and library screenings, we identified amino acid changes that abrogate the binding of therapeutic monoclonal antibodies targeting FLT3, CD123 and KIT, and optimized a base-editing approach to introduce them into CD34+ HSPCs, which retain long-term engraftment and multilineage differentiation ability. After CAR T cell treatment, we confirmed resistance of epitope-edited haematopoiesis and concomitant eradication of patient-derived acute myeloid leukaemia xenografts. Furthermore, we show that multiplex epitope engineering of HSPCs is feasible and enables more effective immunotherapies against multiple targets without incurring overlapping off-tumour toxicities. We envision that this approach will provide opportunities to treat relapsed/refractory acute myeloid leukaemia and enable safer non-genotoxic conditioning.

The impact of Covid-19 in proximal femur fractures. An observational study of the mortality rate.

BACKGROUND AND AIM: Fractures of the proximal femur in the elderly are probably the leading cause of death in the orthopedic patients. Furthermore, after the spread of the pandemic, the mortality rate in the elderly has certainly increased. The aim of our study is to evaluate whether the mortality following proximal femur fractures is affected by the concomitant pandemic. METHODS: We admitted to our study patients over 65 years old, who presented to our Emergency Room with a diagnosis of proximal femur fracture in the first quarter of the years 2019, the period before the development of the pandemic, of 2020 during the pandemic and of 2021 with the new wave of Covid-19. 2022 was not taken into consideration because the mortality data are not yet available and to have at least one year follow-up after surgery. All patients were divided by fracture's type and treatment; the time elapsed from trauma to surgery and from trauma to discharge was also evaluated. For each deceased patient, we considered the time elapsed from the operation to death and whether there was an episode of positivity to Covid-19 following the trauma and after discharge (all patients had a negative swab at the time of admission). CONCLUSIONS: Fractures of the proximal femur in the elderly patient are undoubtedly an important cause leading to the death. The spreading of the Covid-19 pandemic has allowed our department to reduce the gap between trauma and intervention time and from trauma to discharge which is undoubtedly a positive prognostic factor. However, the concurrence of a positivity from the virus does not seem to influence the mortality times following the fracture.

Longitudinal single-cell profiling of chemotherapy response in acute myeloid leukemia.

Acute myeloid leukemia may be characterized by a fraction of leukemia stem cells (LSCs) that sustain disease propagation eventually leading to relapse. Yet, the contribution of LSCs to early therapy resistance and AML regeneration remains controversial. We prospectively identify LSCs in AML patients and xenografts by single-cell RNA sequencing coupled with functional validation by a microRNA-126 reporter enriching for LSCs. Through nucleophosmin 1 (NPM1) mutation calling or chromosomal monosomy detection in single-cell transcriptomes, we discriminate LSCs from regenerating hematopoiesis, and assess their longitudinal response to chemotherapy. Chemotherapy induced a generalized inflammatory and senescence-associated response. Moreover, we observe heterogeneity within progenitor AML cells, some of which proliferate and differentiate with expression of oxidative-phosphorylation (OxPhos) signatures, while others are OxPhos (low) miR-126 (high) and display enforced stemness and quiescence features. miR-126 (high) LSCs are enriched at diagnosis in chemotherapy-refractory AML and at relapse, and their transcriptional signature robustly stratifies patients for survival in large AML cohorts.

Five-years Control after a Delayed Diagnosis of a Traumatic Posterior Hip Dislocation in a 5 years Old Boy- A Case Report.

Introduction: Evaluation of pain in children after trauma can sometimes be difficult; in particular, a knee pain in a child could originate from the hip, until evidence of the contrary. Often is the low-energy trauma that leads to a joint dislocation in children. Furthermore, the present guidelines state that a hip dislocation in a child should be replaced within 6 (maximum 12) hours, to reduce the risk of avascular necrosis (AVN) of the femoral head. Case Presentation: After falling during sports activity at the kindergarten, a 5-years-old boy was taken to the emergency room of a small hospital with severe pain in his right knee. After the visit and the instrumental diagnosis, he was afterward discharged with the diagnosis of contusion of the thigh. After a week of pain and inability to load despite the analgesic therapy, he was accompanied to our hospital, from which the diagnosis of hip dislocation emerged and then reduced in short sedation. The next day he underwent to a magnetic resonance imaging (MRI) examination and pelvic-podalic cast immobilization. At the following check-ups, he had no more pain and the active ROM was complete. A long-term control after 5 years showed a complete and painless active ROM and the MRI showed a normal growth of the bone, without any sign of AVN of the femoral head. Conclusion: Despite the long waiting period and going against the guidelines, the child recovered his full daily and physical activity, without necrosis of the femoral head, growth disorder, or dysmetria in the lower limbs.

Curing Hemoglobinopathies: Challenges and Advances of Conventional and New Gene Therapy Approaches.

Inherited hemoglobin disorders, including beta-thalassemia (BT) and sickle-cell disease (SCD), are the most common monogenic diseases worldwide, with a global carrier frequency of over 5%.1 With migration, they are becoming more common worldwide, making their management and care an increasing concern for health care systems. BT is characterized by an imbalance in the α/ß-globin chain ratio, ineffective erythropoiesis, chronic hemolytic anemia, and compensatory hemopoietic expansion.1 Globally, there are over 25,000 births each year with transfusion-dependent thalassemia (TDT). The currently available treatment for TDT is lifelong transfusions and iron chelation therapy or allogenic bone marrow transplantation as a curative option. SCD affects 300 million people worldwide2 and severely impacts the quality of life of patients who experience unpredictable, recurrent acute and chronic severe pain, stroke, infections, pulmonary disease, kidney disease, retinopathy, and other complications. While survival has been dramatically extended, quality of life is markedly reduced by disease- and treatment-associated morbidity. The development of safe, tissue-specific and efficient vectors, and efficient gene-editing technologies have led to the development of several gene therapy trials for BT and SCD. However, the complexity of the approach presents its hurdles. Fundamental factors at play include the requirement for myeloablation on a patient with benign disease, the age of the patient, and the consequent bone marrow microenvironment. A successful path from proof-ofconcept studies to commercialization must render gene therapy a sustainable and accessible approach for a large number of patients. Furthermore, the cost of these therapies is a considerable challenge for the health care system. While new promising therapeutic options are emerging,3,4 and many others are on the pipeline,5 gene therapy can potentially cure patients. We herein provide an overview of the most recent, likely potentially curative therapies for hemoglobinopathies and a summary of the challenges that these approaches entail.

Epidemiológica del ataque cerebro vascular en un hospital universitario / Epidemiological of cerebrovascular attack in a university hospital / Epidemiologia do ataque cerebrovascular em hospital universitário

Resumen: Introducción: El ataque cerebro vascular es una enfermedad prevalente en nuestro medio con elevada morbimortalidad. El Hospital Pasteur es un centro de tercer nivel, que asiste un elevado número de pacientes con esta patología. Conocer los datos epidemiológicos de esta afección permitirá desarrollar medidas de promoción de salud y prevención primaria. Identificar la forma de presentación clínica y los algoritmos de estudio, permitirán un adecuado diagnóstico, tratamiento precoz y desarrollo de medidas de prevención secundaria. Objetivos: Conocer las características sociodemográficas de la población con diagnóstico de ataque cerebro vascular o accidente isquémico transitorio asistidas en las salas de medicina del Hospital Pasteur, los factores de riesgo asociados, las formas de presentación clínica y precisar si se cumplió con el algoritmo diagnóstico propuesto. Métodos y procedimiento: Estudio descriptivo observacional y transversal realizado en el Hospital Pasteur. La población de estudio fueron pacientes adultos ingresados en sala de medicina con diagnóstico de ataque cerebro vascular o accidente isquémico transitorio que presentaron el evento durante su internación, en el periodo comprendido entre Julio y Setiembre de 2018. Resultados y discusión: Se recabaron datos de 29 pacientes, 20 de sexo femenino. La media de edad fue de 70.34 años. La naturaleza isquémica fue la más prevalente. Los factores de riesgo cardiovascular más frecuentes fueron HTA, sedentarismo, dislipemia y tabaquismo. La principal forma de presentación fue síndrome piramidal. Se cumplió con el algoritmo diagnostico en todos los pacientes. Conclusión: Conocer los factores de riesgo, naturaleza y forma de presentación clínica permite elaborar estrategias de prevención primaria y secundaria para el abordaje integral de estos pacientes, intentando así reducir la incidencia y secuelas de esta enfermedad.

Abstract: Introduction: Acute ischemic stroke is a prevalent condition in our working environment, with high morbility and mortality. Hospital Pasteur is a tertiary level institution, which assists an elevated number of patients with acute ischemic stroke. Getting to know its epidemiologic characteristics will enable the development of health promotion and primary prevention measures. Identifying its clinical presentation form and applying validated study algorithms will allow for a proper diagnosis, early treatment and development of secondary prevention measures. Objectives: To study the sociodemographic characteristics of patients diagnosed with acute ischemic stroke or transient ischemic attack assisted in Hospital Pasteur´s Internal Medicine wards, their associated risk factors, clinical presentation and to determine whether the proposed study algorithm was followed. Methodology and procedure: This is a descriptive, observational and transversal study which took place at Hospital Pasteur. The population consisted of adult patients admitted to Internal Medicine wards with the diagnosis of acute ischemic stroke, transient ischemic attack or who presented the event during their stay, between the months of July and September 2018. Results and discussion: The data of 29 patientes was obtained; 20 were female. The mean age was 70.34 years. Ischemic nature was the most prevalent. The most frequent risk factors were arterial hypertension, sedentary lifestyle, dyslipidemia and smoking. Pyramidal syndrome was the most common clinical presentation. A study algorithm was followed in all patients. Conclusion: Getting to know the risk factors, nature and clinical presentation form of AIS and TIA allows for the creation of primary and secondary prevention strategies for the comprehensive approach of these patients, therefore intending to reduce this disease´s incidence and its terrible consequences.

Resumo: Introdução: O ataque cerebrovascular é uma doença prevalente em nosso meio, com alta morbimortalidade. O Hospital Pasteur é um centro de terceiro nível, que auxilia um grande número de pacientes com essa patologia. Conhecer os dados epidemiológicos dessa condição permitirá o desenvolvimento de ações de promoção da saúde e prevenção primária. Identificar a forma de apresentação clínica e os algoritmos do estudo permitirá um diagnóstico adequado, tratamento precoce e desenvolvimento de medidas de prevenção secundária. Objetivos: Conhecer as características sociodemográficas da população com diagnóstico de ataque cerebrovascular ou ataque isquêmico transitório assistido nas salas médicas do Hospital Pasteur, os fatores de risco associados, as formas de apresentação clínica e determinar se o algoritmo de diagnóstico proposto foi atendido. Métodos e procedimentos: Estudo observacional e transversal descritivo realizado no Hospital Pasteur. A população do estudo foi de pacientes adultos admitidos na enfermaria com diagnóstico de ataque cerebrovascular, ataque isquêmico transitório que apresentaram o evento durante sua internação, no período entre julho e setembro de 2018. Resultados e discussão: Os dados foram coletados de 29 pacientes, sendo 20 do sexo feminino. A idade média foi de 70,34 anos, sendo a natureza isquêmica a mais prevalente. Os fatores de risco cardiovascular mais frequentes foram hipertensão arterial, sedentarismo, dislipidemia e tabagismo. A principal forma de apresentação foi a síndrome piramidal. O algoritmo de diagnóstico foi preenchido em todos os pacientes. Conclusão: Conhecer os fatores de risco, natureza e forma de apresentação clínica permite desenvolver estratégias de prevenção primária e secundária para abordagem abrangente desses pacientes, buscando reduzir a incidência e sequelas da doença.

Knee stability, athletic performance and sport-specific tasks in non-professional soccer players after ACL reconstruction: comparing trans-tibial and antero-medial portal techniques.

BACKGROUND: a wrong position of bone tunnels, in particular on the femur, is one of the most frequent causes of a failed anterior cruciate ligament (ACL) reconstruction. Several studies demonstrated that drilling the femoral tunnel through the antero-medial portal (AMP) allows a more anatomical placement on the lateral femoral condyle and higher knee stability, compared to trans-tibial (TT) technique. The aim of this study was to retrospectively evaluate two groups of soccer players operated on for ACL reconstruction according to either one of these two techniques. METHODS: two groups of non-professional soccer players operated on for a single bundle ACL reconstruction with hamstrings autograft using either a TT (20 patients) or an AMP (23 patients) technique were retrospectively evaluated with KT-1000 arthrometer, manual pivot shift test, isokinetic test, the incremental treadmill-running test, athletic and sport specific tasks, and knee scores (IKDC, Lysholm and KOOS). RESULTS: the AMP group showed better results at pivot shift test and KOOS, but lower flexion angles at single leg squat test. There were no differences in all the other considered outcomes. CONCLUSIONS: the better rotational stability of the knee achieved in AMP group did not lead to significantly better clinical and functional results in our patients. LEVEL OF EVIDENCE III TREATMENT STUDY: Case-control study.

Anestesia en la distrofia miotónica: reporte de dos casos / Anesthesia in miotonic distrophy: report of two cases

El siguiente reporte describe dos pacientes con Distrofia Miotónica. El primero de ellos fue una embarazada de 28 años, gesta IV, paridad I, y 37,5 semanas de gestación. Se internó para operación cesárea electiva debido a un monitoreo fetal no reactivo. El segundo caso se trató de una paciente de 43 años programada para efectuar una tiroidectomía lobar remanente. Se presenta la conducta anestésica de ambos casos, condicionada a la enfermedad de base.