Cellular Interactions in Hemopoietic Progenitor Cell Homing: A Review

Within the bone marrow microenvironment, dynamic cellular interactions are constantly occurring. These interactions involve hemopoietic stem cells, progenitor cells and maturing cells, physically interacting with other cells, some of which may function as accessory cells, and others which comprise the stromal elements; hemopoietic cells also interact with non-cellular elements, such as glycoproteins and fibrous proteins of the extracellular matrix (ECM). These interactions serve to regulate normal hemopoiesis by allowing the communication of regulatory information, migration and subsequent homing of stem cells within specific organs, and presentation of hemopoietic growth factors in a biologically relevant fashion. The goal of this review is to examine the specific cellular interactions that relate to the phenomenon of homing of intravenously transplanted stem cells to the bone marrow

Selective interactions between epithelial tumour cells and bone marrow mesenchymal stem cells

This work is a comparative study on the features displayed by an epithelial metastatic breast cancer cell line (MCF-7) when set in co-culture with human bone marrow mesenchymal stem cells (MSC) or a feeder layer of 3T3 fibroblasts. MSC, a subset of non-haematopoietic cells in the marrow stroma, display a potential for self-renewal, proliferation and differentiation into precursors for bone, cartilage, connective and muscular tissue. Adhesion of MCF-7 cells to monolayers of MSC or 3T3 was high (95 and 85% respectively). Once attached, MCF-7 grow well on both monolayers. Morphology of MCF-7 cells, as analysed by light and epifluorescence microscopy, revealed that MCF-7 cells grow in clusters on 3T3, but disperse on MSC. Concomitant with the lost of their aggregation status, MCF-7 on MSC express low levels of the intercellular adhesion molecules, E-cadherin and epithelial-specific antigen (ESA). These results suggest that MSC represent an appropriate cell target to investigate the cellular and molecular events occurring at the interface of epithelial-marrow stromal interactions. Together, the model here described should permit to further evaluate the significance and prognostic impact of the shift of micrometastatic cells from a cluster-aggregated into a single-cell status. © 2000 Cancer Research Campaig

Risk factors for symptomatic retears after arthroscopic repair of full-thickness rotator cuff tears

Background: Factors affecting a rotator cuff symptomatic retear after arthroscopic repair have yet to be clearly identified, since they usually influence the surgical decisions. Methods: Consecutive patients with full-thickness tear of the supraspinatus who underwent arthroscopic repair were retrospectively analyzed. Cases of symptomatic retear, defined as Sugaya type IV and V on magnetic resonance imaging, associated with intensive pain and/or functional impairment were identified at follow-up. The patients with no symptomatic retear were selected as the control group. Information from potential risk factors of symptomatic retear, including depression and subacromial corticosteroid injections, was extracted from the medical records. The statistical analysis included multivariant logistic regression. Results: The symptomatic retear rate was 9.5% in 158 patients. Patients in the symptomatic retear group were more likely to be smoking, to have massive tears, a short acromiohumeral distance, and moderate to severe fatty infiltration. They also had had more frequently subacromial corticosteroid injections and depression. However, following the multiple logistic regression analysis, only massive tears and moderate to severe fatty infiltration remained significantly associated. Similarly, in relation to the study hypothesis, both corticosteroid injections (odds ratio [OR] 6.66, 95% confidence interval [CI] 1.49, 29.81; P =.013) and depression (OR 8.26, IC 1.04, 65.62; P =.046) were significantly associated with symptomatic retear risk. Conclusions: This study found support for the hypothesis that both depression and corticosteroid infiltration before surgery are independent risk factors for symptomatic retear after arthroscopic repair of rotator cuff

The social media debate on the educational use of smartphones. Discourses of promotion and prohibition

Pedro C. Mellado Moreno – Universidad Rey Juan Carlos - 0000-0001-8982-2120Josefina Patiño Masó – Universitat de Girona - 0000-0002-2322-2437Francisco J. Ramos Pardo – Universidad de Castilla-La Mancha - 0000-0003-4989-7931Meritxell Estebanell Minguell – Universitat de Girona - 0000-0002-6576-3207Recepción: 16.06.2022 | Aceptado: 25.10.2022Correspondencia a través de ORCID: Pedro C. Mellado-Moreno - 0000-0001-8982-2120Financiación: La presente investigación se enmarca en el proyecto «Jóvenes y móviles en el aula. Discursos y dinámicas de prohibición, promoción e indeterminación» PID2019-108041RB-100, financiado por el Ministerio de Ciencia e Innovación del Gobierno de España/Agencia Estatal de Investigación/10.13039/501100011033.2020-2023Área o categoría del conocimiento: MultidisciplinarEditora: Diana Marín Suelves - Universidad de Valencia - ORCID: 0000-0002-5346-8665Revisión por pares abierta: Tania Caamaño Liñares - 0000-0003-0597-2645Revisión por pares abierta: Ángel Emiro Páez Moreno - 0000-0002-0924-3506Las redes sociales se han convertido en uno de los medios con mayor influencia en el debate actual y la opinión pública. Las cuestiones controvertidas en educación, como es el uso de los móviles con fines educativos, no son ajenas a esta capacidad de influencia. El objetivo de este estudio es identificar las principales ideas y argumentos comunicados en medios y redes sociales asociados a la promoción o prohibición del uso del móvil en el aula Para conocer el estado de esta cuestión se ha optado por emplear el motor de búsqueda de Google en las plataformas de las principales redes sociales. Los resultados ratifican la presencia de este debate en redes sociales, que suele estar protagonizado por perfiles docentes y perfiles de medios de comunicación, así como la confrontación de argumentos que giran en torno a la promoción o prohibición. Los perfiles educativos tienden a mostrar una posición favorable hacia el uso de los móviles en el aula, frente a los perfiles de medios de comunicación. Los argumentos asociados a la promoción se centran en el aprovechamiento del potencial educativo de los móviles, mientras que los discursos de prohibición alertan de la capacidad distractora del móvil y su papel en las situaciones de acoso escolar.Abstract: Social networks have become one of the most influential media in public debate and opinion. Controversial issues in education, such as the use of mobile phones in the classroom, are no stranger to this capacity for influence. The main goal of this study is to identify the principal ideas and arguments in media and social networks associated with the promotion or prohibition of educational mobile phones use in classroom. In order to find out the state of this issue, we have chosen to use the Google search engine on the platforms of the main social networks. The results confirm the presence of this debate on social networks, which tends to be led by educational profiles and media profiles, as well as the confrontation of arguments revolving around promotion or prohibition. Educational profiles tend to show a favorable position towards the use of mobiles in the classroom, compared to media profiles. The arguments associated with promotion focus on the educational potential of mobiles, while the prohibition discourses warn of the distracting capacity of mobiles and their role in bullying situations.Universidad Rey Juan CarlosUniversitat de GironaUniversidad de Castilla la ManchaUniversitat de GironaXXIX Jornadas Internacionales Universitarias de Tecnología Educativa - JUTE 202

Azithromycin to Prevent Pertussis in Household Contacts, Catalonia and Navarre, Spain, 2012-2013

We retrospectively assessed the effectiveness of azithromycin in preventing transmission of pertussis to a patient's household contacts. We also considered the duration between symptom onset in the primary patient and azithromycin administration. We categorized contacts into 4 groups: those treated within 21 days after illness onset in the primary patient. We studied 476 primary index patients and their 1,975 household contacts, of whom 4.5% were later identified as having pertussis. When contacts started chemoprophylaxis within 14 days after primary patient's symptom onset was less effective. We recommend that contacts of persons with pertussis begin chemoprophylaxis within <14 days after primary patient's symptom onset

Factors Associated to Duration of Hepatitis A Outbreaks: Implications for Control

Even though hepatitis A mass vaccination effectiveness is high, outbreaks continue to occur. The aim of this study was to investigate the association between duration and characteristics of hepatitis A outbreaks. Hepatitis A (HA) outbreaks reported between 1991 and 2007 were studied. An outbreak was defined as ≥2 epidemiologically-linked cases with ≥1 case laboratory-confirmed by detection of HA immunoglobulin M (IgM) antibodies. Relationships between explanatory variables and outbreak duration were assessed by logistic regression. During the study period, 268 outbreaks (rate 2.45 per million persons-year) and 1396 cases (rate 1.28 per 105 persons-year) were reported. Factors associated with shorter duration were time to intervention (OR = 0.96; 95% CI: 0.94–0.98) and school setting (OR = 0.39; 95% CI: 0.16–0.92). In person-to-person transmission outbreaks only time to intervention was associated with shorter outbreak duration (OR = 0.96; 95% CI: 0.95–0.98). The only variables associated with shorter outbreak duration were early administration of IG or vaccine and a school setting. Timely reporting HA outbreaks was associated with outbreak duration. Making confirmed HA infections statutory reportable for clinical laboratories could diminish outbreak duration

Detection of norovirus in saliva samples from acute gastroenteritis cases and asymptomatic subjects : Association with age and higher shedding in stool

Norovirus infections are a leading cause of acute gastroenteritis outbreaks worldwide and across all age groups, with two main genogroups (GI and GII) infecting humans. The aim of our study was to investigate the occurrence of norovirus in saliva samples from individuals involved in outbreaks of acute gastroenteritis in closed and semiclosed institutions, and its relationship with the virus strain, virus shedding in stool, the occurrence of symptoms, age, and the secretor status of the individual. Epidemiological and clinical information was gathered from norovirus outbreaks occurring in Catalonia, Spain during 2017-2018, and stool and saliva samples were collected from affected and exposed resident individuals and workers. A total of 347 saliva specimens from 25 outbreaks were analyzed. Further, 84% of individuals also provided a paired stool sample. For GII infections, norovirus was detected in 17.9% of saliva samples from symptomatic cases and 5.2% of asymptomatic individuals. Positivity in saliva occurred in both secretors and nonsecretors. None of the individuals infected by norovirus GI was positive for the virus in saliva. Saliva positivity did not correlate with any of the studied symptoms but did correlate with age ≥ 65 years old. Individuals who were positive in saliva showed higher levels of virus shedding in stool. Mean viral load in positive saliva was 3.16 ± 1.08 log10 genome copies/mL, and the predominance of encapsidated genomes was confirmed by propidium monoazide (PMA)xx-viability RTqPCR assay. The detection of norovirus in saliva raises the possibility of oral-to-oral norovirus transmission during the symptomatic phase and, although to a lesser extent, even in cases of asymptomatic infections

Characterization of Spontaneous Bone Marrow Recovery after Sublethal Total Body Irradiation: Importance of the Osteoblastic/Adipocytic Balance

Many studies have already examined the hematopoietic recovery after irradiation but paid with very little attention to the bone marrow microenvironment. Nonetheless previous studies in a murine model of reversible radio-induced bone marrow aplasia have shown a significant increase in alkaline phosphatase activity (ALP) prior to hematopoietic regeneration. This increase in ALP activity was not due to cell proliferation but could be attributed to modifications of the properties of mesenchymal stem cells (MSC). We thus undertook a study to assess the kinetics of the evolution of MSC correlated to their hematopoietic supportive capacities in mice treated with sub lethal total body irradiation. In our study, colony-forming units – fibroblasts (CFU-Fs) assay showed a significant MSC rate increase in irradiated bone marrows. CFU-Fs colonies still possessed differentiation capacities of MSC but colonies from mice sacrificed 3 days after irradiation displayed high rates of ALP activity and a transient increase in osteoblastic markers expression while pparγ and neuropilin-1 decreased. Hematopoietic supportive capacities of CFU-Fs were also modified: as compared to controls, irradiated CFU-Fs significantly increased the proliferation rate of hematopoietic precursors and accelerated the differentiation toward the granulocytic lineage. Our data provide the first evidence of the key role exerted by the balance between osteoblasts and adipocytes in spontaneous bone marrow regeneration. First, (pre)osteoblast differentiation from MSC stimulated hematopoietic precursor's proliferation and granulopoietic regeneration. Then, in a second time (pre)osteoblasts progressively disappeared in favour of adipocytic cells which down regulated the proliferation and granulocytic differentiation and then contributed to a return to pre-irradiation conditions

Mesenchymal Stem Cells Exhibit Firm Adhesion, Crawling, Spreading and Transmigration across Aortic Endothelial Cells: Effects of Chemokines and Shear

Mesenchymal stem cells (MSCs) have anti-inflammatory and immunosuppressive properties and may be useful in the therapy of diseases such as arteriosclerosis. MSCs have some ability to traffic into inflamed tissues, however to exploit this therapeutically their migratory mechanisms need to be elucidated. This study examines the interaction of murine MSCs (mMSCs) with, and their migration across, murine aortic endothelial cells (MAECs), and the effects of chemokines and shear stress. The interaction of mMSCs with MAECs was examined under physiological flow conditions. mMSCs showed lack of interaction with MAECs under continuous flow. However, when the flow was stopped (for 10min) and then started, mMSCs adhered and crawled on the endothelial surface, extending fine microvillous processes (filopodia). They then spread extending pseudopodia in multiple directions. CXCL9 significantly enhanced the percentage of mMSCs adhering, crawling and spreading and shear forces markedly stimulated crawling and spreading. CXCL9, CXCL16, CCL20 and CCL25 significantly enhanced transendothelial migration across MAECs. The transmigrated mMSCs had down-regulated receptors CXCR3, CXCR6, CCR6 and CCR9. This study furthers the knowledge of MSC transendothelial migration and the effects of chemokines and shear stress which is of relevance to inflammatory diseases such as arteriosclerosis