Pérdida de Hueso Tibial

Se presenta un caso de revitalización de un gran fragmento de tibia liofilizado y reimplantado dos meses después del accidente. Se propone como alternativa cuando no se dispone de banco de hueso ni unidad de microcirugíaThe viability of a bone segment of the tibia, preserved by lyophilization and reimplanted two month after the accident is reported in one case. The method used in the present case can be an alternative in Centers without facilities of microsurgical unit or bone banks

Osteosíntesis externa: Rigidez y Elasticidad

Los autores revisan la experiencia acumulada en el tratamiento de fracturas abiertas de tibia y peroné con atricción de partes blandas correspondientes a los grados II y III de CAUCHOIX. En una serie de 15 casos hemos usado el fijador de HOFFMAN-VIDAL y en otra serie de 15 casos el fijador monolateral Orthofix. El método de fijación elástica (fijador monolateral Orthofix) representa una gran seguridad en la consolidación y un acortamiento del tiempo de tratamiento en comparación con el método de fijación rígida (fijador de HOFFMAN-VIDAL).The authors review the experience obtained in the treatment of tibial and fibular open fractures with important soft tissue s attrition corresponding to Cauchoix's grade II and III. In a series of 15 cases they have used the Hoffman-Vidal's external fixer and in other series of 15 case s they have used the Orthofix monolateral external fixer. The method of elastic fixation (the Orthofix monolateral external fixer) is highly reliable in the knitting process and results in a shortening in the period of tretament in comparison with the method of rigid fixation (the Hoffman-Vidal's external fixer)

La fijación externa en los grandes traumatismos

La fijación precoz de las fracturas del paciente politraumatizado mejora su morbilidad y mortalidad. Las puculariedades de la fijación externa la convierten en un método de fijación especialmente indicado para estos pacientes, en especial para las fracturas de pelvis y las fracturas de fémur y tibia. En caso de conversión posterior a enclavado endomedular se aconseja realizarlo antes de las 2 semanas de evolución y en ausencia de infección de los trayectos de los clavos.Early fracture in multiple trauma patient improves his morbidity and mortality. Because of its peculiarities, external stabilization is a fixation method specially indicated for the treatment of these patients, particularly for pelvic, femoral and tibial fractures. Conversion to endomedular nailing is advisable in the first 2 weeks after injury and without pintrack infection

Fijación externa en las fracturas-luxaciones centrales de cadera: a propósito de 3 casos

Se presentan tres casos de fractura-luxación central de cadera tratados mediante estabilización y reducción progresiva con fijación externa. Las ventajas de este tratamiento con respecto al tratamiento conservador o quirúrgico son la estabilización inmediata y la sencillez de realización. Los resultados de fijación externa obtenidos en estos pacientes demuestran una rehabilitación y deambulación precoz e independiente. La recuperación clínica y funcional fue satisfactoria en dos casos. En otro caso, con mala reducción quirúrgica previa, el resultado fue pobre.Three cases of central fracture-dislocation of the hip treated by stabilization and progressive reduction by means of external fixation are presented. The advantages of this procedure over the conservative or even the surgical treatment are the early stabilization and the fact that the technique is a step-forward procedure. The results obtained in these patients with external fixation of the hip led to a good rehabilitation and to an early independent ambulation. The clinical and functional recovery of these patients was satisfactory in two cases. In other with previous failed open reduction the result was poor

Establishment of a murine epidermal cell line suitable for in vitro and in vivo skin modelling

<p>Abstract</p> <p>Background</p> <p>Skin diseases are a major health problem. Some of the most severe conditions involve genetic disorders, including cancer. Several of these human diseases have been modelled in genetically modified mice, thus becoming a highly valuable preclinical tool for the treatment of these pathologies. However, development of three-dimensional models of skin using keratinocytes from normal and/or genetically modified mice has been hindered by the difficulty to subculture murine epidermal keratinocytes.</p> <p>Methods</p> <p>We have generated a murine epidermal cell line by serially passaging keratinocytes isolated from the back skin of adult mice. We have termed this cell line COCA. Cell culture is done in fully defined media and does not require feeder cells or any other coating methods.</p> <p>Results</p> <p>COCA retained its capacity to differentiate and stratify in response to increased calcium concentration in the cell culture medium for more than 75 passages. These cells, including late passage, can form epidermis-like structures in three-dimensional <it>in vitro </it>models with a well-preserved pattern of proliferation and differentiation. Furthermore, these cells form epidermis in grafting assays <it>in vivo</it>, and do not develop tumorigenic ability.</p> <p>Conclusions</p> <p>We propose that COCA constitutes a good experimental system for <it>in vitro </it>and <it>in vivo </it>skin modelling. Also, cell lines from genetically modified mice of interest in skin biology could be established using the method we have developed. COCA keratinocytes would be a suitable control, within a similar background, when studying the biological implications of these alterations.</p

Functional specificity of the members of the Sos family of Ras-GEF Activators: Novel role of Sos2 in control of epidermal stem cell homeostasis

© 2021 by the authors.Prior reports showed the critical requirement of Sos1 for epithelial carcinogenesis, but the specific functionalities of the homologous Sos1 and Sos2 GEFs in skin homeostasis and tumorigenesis remain unclear. Here, we characterize specific mechanistic roles played by Sos1 or Sos2 in primary mouse keratinocytes (a prevalent skin cell lineage) under different experimental conditions. Functional analyses of actively growing primary keratinocytes of relevant genotypes—WT, Sos1-KO, Sos2-KO, and Sos1/2-DKO—revealed a prevalent role of Sos1 regarding transcriptional regulation and control of RAS activation and mechanistic overlapping of Sos1 and Sos2 regarding cell proliferation and survival, with dominant contribution of Sos1 to the RAS-ERK axis and Sos2 to the RAS-PI3K/AKT axis. Sos1/2-DKO keratinocytes could not grow under 3D culture conditions, but single Sos1-KO and Sos2-KO keratinocytes were able to form pseudoepidermis structures that showed disorganized layer structure, reduced proliferation, and increased apoptosis in comparison with WT 3D cultures. Remarkably, analysis of the skin of both newborn and adult Sos2-KO mice uncovered a significant reduction of the population of stem cells located in hair follicles. These data confirm that Sos1 and Sos2 play specific, cell-autonomous functions in primary keratinocytes and reveal a novel, essential role of Sos2 in control of epidermal stem cell homeostasis.The E.S. group was supported by grants from ISCIII-MCUI (FIS PI19/00934), JCyL (SA264P18-UIC 076), Areces Foundation (CIVP19A5942), Solorzano-Barruso Foundation (FS/32-2020), and by ISCIII-CIBERONC (group CB16/12/00352). Research was co-financed by FEDER funds. The J.M.P. lab is co-funded by European Regional Development Fund (FEDER) grants from Science and Innovation (SAF2015-66015-R and PID2019-110758RB-I00 to J.M.P.) and Instituto de Salud Carlos III (CIBERONC no. CB16/12/00228 to J.M.P.). The XRB lab is funded by “la Caixa” Banking Foundation (HR20-00164), the Castilla-León autonomous government (CSI252P18, CSI145P20, CLC-2017-01), the Spanish Ministry of Science and Innovation (MSI) (RTI2018-096481-B-100), and the Spanish Association against Cancer (GC16173472GARC). The CIC is supported by the Programa de Apoyo a Planes Estratégicos de Investigación de Estructuras de Investigación de Excelencia of the Castilla-León autonomous government (CLC-2017-01). L.F.L.-M. and N.F.-P. contracts have been supported by funding from the Spanish Ministry of Universities (FPU13/02923, FPU17/03912) and, in the case of L.F.L.M., by CLC-2017-01 grant

EMT and induction of miR-21 mediate metastasis development in Trp53-deficient tumours

Missense mutations in TP53 gene promote metastasis in human tumours. However, little is known about the complete loss of function of p53 in tumour metastasis. Here we show that squamous cell carcinomas generated by the specific ablation of Trp53 gene in mouse epidermis are highly metastatic. Biochemical and genome-wide mRNA and miRNA analyses demonstrated that metastases are associated with the early induction of epithelial-mesenchymal transition (EMT) and deregulated miRNA expression in primary tumours. Increased expression of miR-21 was observed in undifferentiated, prometastatic mouse tumours and in human tumours characterized by p53 mutations and distant metastasis. The augmented expression of miR-21, mediated by active mTOR and Stat3 signalling, conferred increased invasive properties to mouse keratinocytes in vitro and in vivo, whereas blockade of miR-21 in a metastatic spindle cell line inhibits metastasis development. Collectively these data identify novel molecular mechanisms leading to metastasis in vivo originated by p53 loss in epithelia

Differential role of the RasGEFs Sos1 and Sos2 in mouse skin homeostasis and carcinogenesis

Using Sos1 knockout (Sos1-KO), Sos2-KO, and Sos1/2 double-knockout (Sos1/2-DKO) mice, we assessed the functional role of Sos1 and Sos2 in skin homeostasis under physiological and/or pathological conditions. Sos1 depletion resulted in significant alterations of skin homeostasis, including reduced keratinocyte proliferation, altered hair follicle and blood vessel integrity in dermis, and reduced adipose tissue in hypodermis. These defects worsened significantly when both Sos1 and Sos2 were absent. Simultaneous Sos1/2 disruption led to severe impairment of the ability to repair skin wounds, as well as to almost complete ablation of the neutrophil-mediated inflammatory response in the injury site. Furthermore, Sos1 disruption delayed the onset of tumor initiation, decreased tumor growth, and prevented malignant progression of papillomas in a DMBA (7,12-dimethylbenz[α]anthracene)/TPA (12-O-tetradecanoylphorbol-13-acetate)-induced skin carcinogenesis model. Finally, Sos1 depletion in preexisting chemically induced papillomas resulted also in decreased tumor growth, probably linked to significantly reduced underlying keratinocyte proliferation. Our data unveil novel, distinctive mechanistic roles of Sos 1 and Sos2 in physiological control of skin homeostasis and wound repair, as well as in pathological development of chemically induced skin tumors. These observations underscore the essential role of Sos proteins in cellular proliferation and migration and support the consideration of these RasGEFs as potential biomarkers/therapy targets in Ras-driven epidermal tumors.This study was supported by grants FIS PI16/02137 from ISCIII (MINECO), SA043U16 (UIC 076) from JCyL, and AECC Spain (to E.S.); by MINECO grant SAF2015-66015-R; and by MSyC grants ISCIII-RETIC RD12/0036/0009, PIE 15/00076, and CB/16/00228 (to J.M.P.). This research was cofinanced by FEDER fund

VAV2 signaling promotes regenerative proliferation in both cutaneous and head and neck squamous cell carcinoma

Regenerative proliferation capacity and poor differentiation are histological features usually linked to poor prognosis in head and neck squamous cell carcinoma (hnSCC). However, the pathways that regulate them remain ill-characterized. Here, we show that those traits can be triggered by the RHO GTPase activator VAV2 in keratinocytes present in the skin and oral mucosa. VAV2 is also required to maintain those traits in hnSCC patient-derived cells. This function, which is both catalysis- and RHO GTPase-dependent, is mediated by c-Myc- and YAP/TAZ-dependent transcriptomal programs associated with regenerative proliferation and cell undifferentiation, respectively. High levels of VAV2 transcripts and VAV2-regulated gene signatures are both associated with poor hnSCC patient prognosis. These results unveil a druggable pathway linked to the malignancy of specific SCC subtypes. The Rho signalling pathway is frequently activated in squamous carcinomas. Here, the authors find that the Rho GEF VAV2 is over expressed in both cutaneous and head and neck squamous cell carcinomas and that at the molecular level VAV2 promotes a pro-tumorigenic stem cell-like signalling programme

The Thyroid Hormone Receptors Modulate the Skin Response to Retinoids

[Background]: Retinoids play an important role in skin homeostasis and when administered topically cause skin hyperplasia, abnormal epidermal differentiation and inflammation. Thyroidal status in humans also influences skin morphology and function and we have recently shown that the thyroid hormone receptors (TRs) are required for a normal proliferative response to 12-O-tetradecanolyphorbol-13-acetate (TPA) in mice. [Methodology/Principal Findings]: We have compared the epidermal response of mice lacking the thyroid hormone receptor binding isoforms TRα1 and TRβ to retinoids and TPA. Reduced hyperplasia and a decreased number of proliferating cells in the basal layer in response to 9-cis-RA and TPA were found in the epidermis of TR-deficient mice. Nuclear levels of proteins important for cell proliferation were altered, and expression of keratins 5 and 6 was also reduced, concomitantly with the decreased number of epidermal cell layers. In control mice the retinoid (but not TPA) induced parakeratosis and diminished expression of keratin 10 and loricrin, markers of early and terminal epidermal differentiation, respectively. This reduction was more accentuated in the TR deficient animals, whereas they did not present parakeratosis. Therefore, TRs modulate both the proliferative response to retinoids and their inhibitory effects on skin differentiation. Reduced proliferation, which was reversed upon thyroxine treatment, was also found in hypothyroid mice, demonstrating that thyroid hormone binding to TRs is required for the normal response to retinoids. In addition, the mRNA levels of the pro-inflammatory cytokines TNFα and IL-6 and the chemotactic proteins S1008A and S1008B were significantly elevated in the skin of TR knock-out mice after TPA or 9-cis-RA treatment and immune cell infiltration was also enhanced. [Conclusions/significance]: Since retinoids are commonly used for the treatment of skin disorders, these results demonstrating that TRs regulate skin proliferation, differentiation and inflammation in response to these compounds could have not only physiological but also therapeutic implications.This work was supported by grants BFU2007-62402 and SAF2008-00121 from Ministerio de Ciencia e Innovación, RD06/0020/0036 and RD06/0020/0029 from the Fondo de Investigaciones Sanitarias and by the European Grant CRESCENDO (FP-018652).Peer reviewe