Claudin-6 enhances cell invasiveness through claudin-1 in AGS human adenocarcinoma gastric cancer cells.

Claudins participate in tissue barrier function. The loss of this barrier is associated to metalloproteases-related extracellular matrix and basal membranes degradation. Claudin-1 is a pro-MMP-2 activator and claudin-6 transfected AGS (AGS-Cld6) cells are highly invasive. Our aim was to determine if claudin-6 was direct or indirectly associated with MMP-2 activation and cell invasiveness. Cytofluorometry, cell fractioning, immunoprecipitation, gelatin-zymography, cell migration and invasiveness assays were performed, claudin-2, -6, -7 and -9 transfected AGS cells, anti-MMP-2, -9 and -14, anti-claudins specific antibodies and claudin-1 small interfering RNA were used. The results showed a significant (p<0.001) overexpression of claudin-1 in AGS-Cld6 cell membranes. A strong MMP-2 activity was identified in culture supernatants of AGS-Cld6. Claudin-1 co-localized with MMP-2 and MMP-14; interestingly a significant increase in cell membrane and cytosol MMP-14 expression was detected in AGS-Cld6 cells (p<0.05). Silencing of claudin-1 in AGS-Cld6 cells showed a 60% MMP-2 activity decrease in culture supernatants and a significant decrease (p<0.05) in cell migration and invasiveness. Our results suggest that claudin-6 induces MMP-2 activation through claudin-1 membrane expression, which in turn promotes cell migration and invasiveness.

[Distal biceps brachii rupture in a patient with COVID-19]. / Ruptura de bíceps braquial distal en paciente con COVID-19.

INTRODUCTION: distal biceps tendon injury commonly occurs in male patients between the fifth and sixth decade of life. The mechanism of the injury is an eccentric contraction with the elbow in flexion of 90 degrees. For its surgical treatment, several options have been described in the literature with different approaches, type of suture to be used and various methods of fixing the repair of the distal biceps tendon. The musculoskeletal clinical manifestations of COVID-19 are fatigue, myalgia, arthralgia, but the musculoskeletal effects of COVID-19 remain unclear. CASE REPORT: 46-year-old COVID-19 positive male patient with acute distal biceps tendon injury and secondary to minimal trauma, with no other risk factors. The patient was treated surgically following orthopedic and safety guidelines for the patient and medical staff due to the COVID-19 pandemic. The surgical procedure of the double tension slide (DTS) technique with a single incision in a reliable option and our case of a low morbidity, few complications and a good cosmetic option. CONCLUSION: the management of orthopedic pathologies in COVID-19 positive patients is increasing as well as the ethical and orthopedic implications of the management of these injuries and/or the delay of their care during the pandemic.

INTRODUCCIÓN: la lesión del tendón distal del bíceps se presenta comúnmente en pacientes masculinos entre la quinta y sexta década de la vida. El mecanismo de la lesión es una contracción excéntrica con el codo en flexión de 90o. Para su tratamiento quirúrgico, en la literatura se describen varias opciones con diferentes abordajes, tipo de sutura a utilizar y diversos métodos de fijación de la reparación del tendón distal de bíceps. Las manifestaciones clínicas musculoesqueléticas del COVID-19 son fatiga, mialgia, artralgia, pero los efectos musculoesqueléticos del COVID-19 continúan siendo poco claros. CASO CLÍNICO: paciente masculino de 46 años, COVID-19 positivo, con una lesión aguda del tendón distal del bíceps y secundaria a un trauma mínimo, sin otros factores de riesgo. El paciente fue tratado quirúrgicamente siguiendo las guías ortopédicas y de seguridad para el paciente y el personal médico debido a la pandemia COVID-19. El procedimiento quirúrgico de la técnica de double tension slide (DTS) con una sola incisión es una opción confiable y en nuestro caso de una baja morbilidad, con pocas complicaciones y una buena opción cosmética. CONCLUSIÓN: el manejo de patologías ortopédicas en pacientes COVID-19 positivos va en aumento, así como las implicaciones éticas y ortopédicas del manejo de estas lesiones y/o el retraso de su atención durante la pandemia.

Case report: Disease phenotype associated with simultaneous biallelic mutations in ABCA4 and USH2A due to uniparental disomy of chromosome 1.

Inherited retinal diseases (IRDs) represent a spectrum of clinically and genetically heterogeneous disorders. Our study describes an IRD patient carrying ABCA4 and USH2A pathogenic biallelic mutations as a result of paternal uniparental disomy (UPD) in chromosome 1. The proband is a 9-year-old girl born from non-consanguineous parents. Both parents were asymptomatic and denied family history of ocular disease. Clinical history and ophthalmologic examination of the proband were consistent with Stargardt disease. Whispered voice testing disclosed moderate hearing loss. Next-generation sequencing and Sanger sequencing identified pathogenic variants in ABCA4 (c.4926C>G and c.5044_5058del) and USH2A (c.2276G>T). All variants were present homozygously in DNA from the proband and heterozygously in DNA from the father. No variants were found in maternal DNA. Further analysis of single nucleotide polymorphisms confirmed paternal UPD of chromosome 1. This is the first known patient with confirmed UPD for two recessively mutated IRD genes. Our study expands on the genetic heterogeneity of IRDs and highlights the importance of UPD as a mechanism of autosomal recessive disease in non-consanguineous parents. Moreover, a long-term follow-up is essential for the identification of retinal features that may develop as a result of USH2A-related conditions.

Mammalian STAG3 is a cohesin specific to sister chromatid arms in meiosis I.

Cohesins, which have been characterized in budding yeast and Xenopus, are multisubunit protein complexes involved in sister chromatid cohesion. Regulation of the interactions among different cohesin subunits and the assembly/disassembly of the cohesin complex to chromatin are key steps in chromosome segregation. We previously characterized the mammalian STAG3 protein as a component of the synaptonemal complex that is specifically expressed in germinal cells, although its function in meiosis remains unknown. Here we show that STAG3 has a role in sister chromatid arm cohesion during mammalian meiosis I. Immunofluorescence results in prophase I cells suggest that STAG3 is a component of the axial/lateral element of the synaptonemal complex. In metaphase I, STAG3 is located at the interchromatid domain and is absent from the chiasma region. In late anaphase I and the later stages of meiosis, STAG3 is not detected. STAG3 interacts with the structural maintenance chromosome proteins SMC1 and SMC3, which have been reported to be subunits of the mitotic cohesin complex. We propose that STAG3 is a sister chromatid arm cohesin that is specific to mammalian meiosis I.

The cell cycle inhibitor p21 controls T-cell proliferation and sex-linked lupus development.

Here we show that the cell-cycle regulator p21 is involved in immune system function. T lymphocytes from p21-/- mice exhibit significant proliferative advantage over wild-type cells following prolonged stimulation, but not after primary activation. Consistent with this, p21-deficient mice accumulate abnormal amounts of CD4+ memory cells, and develop loss of tolerance towards nuclear antigens. Similar to human lupus, female p21-deficient mice develop antibodies against dsDNA, lymphadenopathy, and glomerulonephritis, leading to decreased viability. These data demonstrate a specialized role for p21 in the control of T-cell proliferation, tolerance to nuclear antigens, and female-prone lupus. These findings could be the basis for new therapeutic approaches to lupus.

[Hallux valgus mild and moderate; treatment by minimally invasive surgery and its follow-up to 2 years]. / Hallux valgus leve y moderado; tratamiento mediante cirugía de invasión mínima y su seguimiento a 2 años.

INTRODUCTION: The hallux valgus is a very frequent and complex orthopedic pathology. It involves the bone and soft tissue structures of the first toe. There are multiple techniques described for the alignment of the first toe. All technics aim to restore the normal angulation of the toe while using a stable osteotomy through a painless surgical procedure. The minimal invasive techniques have been growing in acceptance since the year 2000, as a viable surgical alternative to treat this pathology. MATERIAL AND METHODS: We included patients with a diagnostic of mild or moderate hallux valgus on whom a minimal invasive procedure was performed to correct the deformity of the first toe. We performed a distal Reverdin/Isham osteotomy on the first metatarsal and an akin osteotomy in the proximal phalanx, a lateral capsular release and a abductor tenotomy. These patients were followed for 24 months after their surgery. RESULTS: Our patients had an adequate correction angular correction, for a distal osteotomy. They had a good pain control, with an adequate mobility in the postoperative period. The patients presented an adequate personal satisfaction, 87% of them had good results. We found an important and statistically significant improvement in the Kitaoka scale. CONCLUSION: The minimal invasive technics for the correction of mild or moderated hallux valgus are a good alternative. Our patients are satisfied with the functional, and cosmetic results.

INTRODUCCIÓN: El hallux valgus es una de las patologías más frecuentes y complejas en la ortopedia. Afecta a los tejidos blandos y óseos del primer dedo. Se encuentran descritas múltiples técnicas para su corrección, todas con un último fin: lograr restaurar el ángulo fisiológico del primer dedo mediante una osteotomía estable y con el menor dolor postquirúrgico posible. Las técnicas de invasión mínima han venido ganando adeptos desde los años 2000 como una alternativa para el tratamiento de esta patología. MATERIAL Y MÉTODOS: Se incluyeron pacientes con diagnóstico de hallux valgus leve o moderado en los que se realizó un procedimiento mínimamente invasivo para corregir la deformidad del primer dedo del pie. Se realizó una osteotomía distal de Reverdin/Isham en el primer metatarsiano y una osteotomía de Akin en la falange proximal, una liberación capsular lateral y una tenotomía abductora. Estos casos fueron seguidos durante 24 meses después de su cirugía. RESULTADO: Nuestros pacientes presentaron una adecuada corrección de la sintomatología dolorosa, retorno a la movilidad articular prequirúrgica y una adecuada satisfacción personal con 87.3% de buenos resultados. Encontramos una mejoría importante en la escala de Kitaoka. Tenemos una adecuada corrección angular para una osteotomía distal. CONCLUSIONES: Las técnicas de invasión mínima para la corrección de hallux valgus moderado y leve son una adecuada herramienta. Nuestros pacientes se encuentran satisfechos con los resultados estéticos y funcionales.

Immune networks. Frequencies of antibody- and idiotype-producing B cell clones in various steady states.

In limiting dilution analysis, the absolute frequencies of lipopolysaccharide-reactive B cell precursors producing anti-trinitrophenyl antibodies or the MOPC460 idiotype were studied in BALB/c mice, either normal, or immunized with antigen (Ab1), the idiotype (Ab2), or a monoclonal anti-idiotype antibody (Ab3). Anti-idiotype immunity results in the suppression of the B cell precursors for the relevant idiotype, and anti-(anti-idiotype) immunity leads to a 10-fold increase in precursor B cell frequencies, with a comparatively lower increase in antibody-producing precursors. The findings can only be explained by variations in the composition of the B cell compartment in the various immune states.

Polarization of chemokine receptors to the leading edge during lymphocyte chemotaxis.

Leukocyte migration in response to cell attractant gradients or chemotaxis is a key phenomenon both in cell movement and in the inflammatory response. Chemokines are quite likely to be the key molecules directing migration of leukocytes that involve cell polarization with generation of specialized cell compartments. The precise mechanism of leukocyte chemoattraction is not known, however. In this study, we demonstrate that the CC chemokine receptors CCR2 and CCR5, but not cytokine receptors such as interleukin (IL)-2Ralpha, IL-2Rbeta, tumor necrosis factor receptor 1, or transforming growth factor betaR, are redistributed to a pole in T cells that are migrating in response to chemokines. Immunofluorescence and confocal microscopy studies show that the chemokine receptors concentrate at the leading edge of the cell on the flattened cell-substratum contact area, induced specifically by the signals that trigger cell polarization. The redistribution of chemokine receptors is blocked by pertussis toxin and is dependent on cell adhesion through integrin receptors, which mediate cell migration. Chemokine receptor expression on the leading edge of migrating polarized lymphocytes appears to act as a sensor mechanism for the directed migration of leukocytes through a chemoattractant gradient.

CC chemokine receptor (CCR)3/eotaxin is followed by CCR4/monocyte-derived chemokine in mediating pulmonary T helper lymphocyte type 2 recruitment after serial antigen challenge in vivo.

Isolated peripheral blood CD4 cells from allergic individuals express CC chemokine receptor (CCR)3 and CCR4 after expansion in vitro. In addition, human T helper type 2 (Th2) cells polarized in vitro selectively express CCR3 and CCR4 at certain stages of activation/differentiation and respond preferentially to the ligands eotaxin and monocyte-derived chemokine (MDC). However, controversy arises when the in vivo significance of this distinct expression is discussed. To address the functional role of CCR3/eotaxin and CCR4/MDC during the in vivo recruitment of Th2 cells, we have transferred effector Th cells into naive mice to induce allergic airway disease. Tracking of these cells after repeated antigen challenge has established that both CCR3/eotaxin and CCR4/MDC axes contribute to the recruitment of Th2 cells to the lung, demonstrating the in vivo relevance of the expression of these receptors on Th2 cells. We have shown that involvement of the CCR3/eotaxin pathway is confined to early stages of the response in vivo, whereas repeated antigen stimulation results in the predominant use of the CCR4/MDC pathway. We propose that effector Th2 cells respond to both CCR3/eotaxin and CCR4/MDC pathways initially, but that a progressive increase in CCR4-positive cells results in the predominance of the CCR4/MDC axis in the long-term recruitment of Th2 cells in vivo.

Interleukin 2 abrogates the nonresponsive state of T cells expressing a forbidden T cell receptor repertoire and induces autoimmune disease in neonatally thymectomized mice.

Under physiological conditions, the vast majority of T cells differentiate in the thymus, an organ that provides an optimal microenvironment for T cell maturation and shapes the T cell repertoire via positive and negative selection processes. In the present report, we demonstrate that neonatal thymectomy of CBA/H mice results in a diminution of T cells in peripheral lymphoid organs (spleen, lymph nodes), but is followed by a marked transient (12 wk) increase in Thy-1+ CD3+ cells in the peritoneal cavity. These cells exhibit predominantly a double-negative (CD4-CD8-) phenotype among which products of the T cell receptor (TCR) V beta 11 gene family (i.e., an I-E-reactive TCR normally deleted in I-E-bearing CBA/H mice) are selectively overexpressed. This observation suggests that, under athymic conditions, T cell differentiation and/or accumulation may occur in the peritoneal cavity. Intraperitoneal inoculation of an interleukin 2 (IL-2) vaccinia virus construct that releases high titers of human IL-2 in vivo induces conversion of these double-negative T cells to either CD4+ CD8- or CD4- CD8+ single positives, and allows in vitro stimulation of TCR V beta 11-bearing cells with a clonotypic anti-V beta antibody. Since IL-2 induces autoimmune manifestations (DNA autoantibodies, rheumatoid factors, and interstitial nephritis) in thymectomized CBA/H mice, but not in sham-treated littermates, this lymphokine is likely to enhance the autoaggressive function of T cells that bear forbidden, potentially autoreactive TCR gene products and that are normally deleted in the thymus.

Isolation and characterization of (gamma, delta) CD4+ T cell clones derived from human fetal liver cells.

Lymphocytes isolated from human fetal liver and expanded in vitro in IL-2-containing media reveal the existence of CD4+ gamma, delta T cells. These cells display differential features of double-negative and CD8+ gamma, delta T cells as well as of CD4+ alpha, beta T cells. Thus, they failed to lyse targets in lectin-mediated killing assays and to perform classical helper functions. These results add new information necessary for a better understanding of the physiological role of the gamma, delta T cells.

Transplanted long-term cultured pre-BI cells expressing calpastatin are resistant to B cell receptor-induced apoptosis.

Long-term cultured pre-B cells are able to differentiate into immunoglobulin (Ig)M-positive B cells (IgM(+) cells) when transplanted into severe combined immunodeficient (SCID) mice. Based on previous studies, here we report the development of a reconstitution assay in nonobese diabetic/SCID (NOD/SCID) mice using pre-B cells, which allows us to study the role of calpains (calcium-activated endopeptidases) during B cell development as well as in B cell clonal deletion. Using this model, we show that calpastatin (the natural inhibitor of calpains) inhibits B cell receptor-induced apoptosis in IgM(+) cells derived from transplanted mice. We thus hypothesize an important function for calpain in sculpting the B cell repertoire.

Distinct expression and function of the novel mouse chemokine monocyte chemotactic protein-5 in lung allergic inflammation.

We have cloned a novel mouse CC chemokine cDNA from the lung during an allergic inflammatory reaction. The protein encoded by this cDNA is chemotactic for eosinophils, monocytes, and lymphocytes in vitro and in vivo. Based on its similarities in sequence and function with other CC chemokines, we have named it mouse monocyte chemotactic protein-5 (mMCP-5). Under noninflammatory conditions, expression of mMCP-5 in the lymph nodes and thymus is constitutive and is generally restricted to stromal cells. Neutralization of mMCP-5 protein with specific antibodies during an allergic inflammatory reaction in vivo resulted in a reduction in the number of eosinophils that accumulated in the lung. Moreover, mMCP-5 mRNA expression in vivo is regulated differently from that of other major CC chemokines in the lung during the allergic reaction, including Eotaxin. The presence of lymphocytes is essential for expression of mMCP-5 by alveolar macrophages and smooth muscle cells in the lung, and the induction of mMCP-5 RNA occurs earlier than that of the eosinophil chemokine Eotaxin during allergic inflammation. In contrast to Eotaxin, mRNA for mMCP-5 can be produced by mast cells. From these results, we postulate that mMCP-5 plays a pivotal role during the early stages of allergic lung inflammation.

The coordinated action of CC chemokines in the lung orchestrates allergic inflammation and airway hyperresponsiveness.

The complex pathophysiology of lung allergic inflammation and bronchial hyperresponsiveness (BHR) that characterize asthma is achieved by the regulated accumulation and activation of different leukocyte subsets in the lung. The development and maintenance of these processes correlate with the coordinated production of chemokines. Here, we have assessed the role that different chemokines play in lung allergic inflammation and BHR by blocking their activities in vivo. Our results show that blockage of each one of these chemokines reduces both lung leukocyte infiltration and BHR in a substantially different way. Thus, eotaxin neutralization reduces specifically BHR and lung eosinophilia transiently after each antigen exposure. Monocyte chemoattractant protein (MCP)-5 neutralization abolishes BHR not by affecting the accumulation of inflammatory leukocytes in the airways, but rather by altering the trafficking of the eosinophils and other leukocytes through the lung interstitium. Neutralization of RANTES (regulated upon activation, normal T cell expressed and secreted) receptor(s) with a receptor antagonist decreases significantly lymphocyte and eosinophil infiltration as well as mRNA expression of eotaxin and RANTES. In contrast, neutralization of one of the ligands for RANTES receptors, macrophage-inflammatory protein 1alpha, reduces only slightly lung eosinophilia and BHR. Finally, MCP-1 neutralization diminishes drastically BHR and inflammation, and this correlates with a pronounced decrease in monocyte- and lymphocyte-derived inflammatory mediators. These results suggest that different chemokines activate different cellular and molecular pathways that in a coordinated fashion contribute to the complex pathophysiology of asthma, and that their individual blockage results in intervention at different levels of these processes.

Superovulatory response of zebu cows treated with pFSH in a single subcutaneous injection followed by an additional intramuscular sub-dose 48 h later.

The aim of this study was to evaluate whether an additional intramuscular (im) injection of pFSH would increase the embryo production in zebu cows superovulated with a single subcutaneous (sc) pFSH injection. Twenty-one Nelore cows were treated with a progesterone vaginal implant (Controlled Internal Drug Relased - CIDR B) and injected im with 2.5 mg estradiol benzoate. Four days later, cows were assigned randomly into three groups and superovulated with pFSH. Groups A and B received single sc injections of 400 and 320 IU, respectively; Group C received multiple im injections of 400 IU in decreasing doses at 12-h intervals over 4 days. In the morning (07:00 am) of day 3 after starting superovulation, cows received im 150 mcg cloprostenol and Group B was additionally injected im with 80 IU of pFSH. CIDR-B was withdrawn in the afternoon (07:00 pm). Cows were inseminated 48 and 62 h after the cloprostenol injection. Embryo collection and corpora lutea (CL) estimation were done 7 days after insemination. Alternation of treatments (crossover design) occurred at a 60-day interval. There was no significant difference (p > 0.05) of CL counts among treatments. The total (transferable and no transferable) number of recovered embryos from Group A (6.9 +/- 1.5) was not different from Group C (9.8 +/- 1.2), whereas Group B (5.7 +/- 1.5) was lower than Group C (p < 0.05). The number of transferable embryos from Groups A (2.4 +/- 0.7) and B (1.7 +/- 0.6) was lower (p < 0.05) than Group C (4.6 +/- 1.2). Lesser (p < 0.05) embryo production from Group B was related to lower recovery rate (46.4%), compared with Groups A (65.1%) and C (81.7%). It was concluded that an additional im subdose of pFSH, injected 48 h after a single subcutaneous (sc) dose of pFSH, does not improve the embryo production in zebu cows.

[99mTc-MAA peritoneal scintigraphy in pleuroperitoneal comunication in peritoneal dialysis patients]. / Gammagrafía peritoneal con 99mTc-MAA en las comunicaciones pleuroperitoneales en pacientes en diálisis peritoneal.

Peritoneal dialysis is a fully-contrasted alternative for the treatment of end-stage renal disease although it is not exempt of complications. Peritonitis and exit-site infections are among the most frequent complications found. Pleural effusion secondary to pleuroperitoneal communication (PPC) is a serious and uncommon complication in these patients. We present the case of a 50-year old man diagnosed of end-stage renal disease undergoing treatment with peritoneal dialysis who presented progressive dyspnea and right pleural effusion. The peritoneal scintigraphy with (99m)Tc-MAA makes it possible to confirm communication of intraperitoneal dialysis fluid to the pleural cavity.

[Anterior ankle impingement: follow-up in 52 cases]. / Pinzamiento anterior de tobillo: seguimiento de la evolución en 52 casos.

INTRODUCTION: The anterior ankle impingement is a common pathology. It is mostly seen in athletes. Pain in the anterior portion of the ankle and limitation in the ankle's dorsiflexion are the most common symptoms. These lesions are commonly preceded by an inversion movement most commonly during soccer. MATERIAL AND METHODS: This is a observational, descriptive, prospective and longitudinal study of 52 consecutive patients with anterior ankle impingement in whom an anterior ankle arthroscopy was perform. The objective is to know the clinical follow-up at least one year. We evaluated numeric pain scale, functional outcomes and personal satisfaction. RESULTS: Of the 52 patients, we had 36 males, and 16 females. Pain scale moved from 5.75 to 0.98 points. The AOFAS scale moved from 73.65 preoperative to 92.98 postoperatively the SFMCP scale went form 72.44 preoperative to 94.48 postop. 23 patients (44.23%) returned to there previous level of sport with in four to seven months form the intervention. CONCLUSIONS: Arthroscopic treatment of the anterior ankle impingement showed significant improvement to 12 months of follow-up. The return to sports activity at the same level prior to the injury was four to seven months.

INTRODUCCIÓN: El pinzamiento anterior de tobillo es una patología común. Se presenta con mayor frecuencia en deportistas, se caracteriza por dolor en la cara anterior acompañado de limitación funcional al realizar la dorsiflexión del tobillo. Se ha observado que la mayor parte de estas lesiones son generadas por un movimiento de inversión repetida y el deporte que más se ve involucrado es el fútbol. MATERIAL Y MÉTODOS: Se trata de un estudio con diseño observacional, descriptivo, prospectivo y longitudinal de 52 pacientes consecutivos con síntomas de pinzamiento anterior de tobillo a quienes se les realizó tratamiento quirúrgico artroscópico. Su objetivo es conocer la evolución clínica con un año de seguimiento mínimo, se evaluaron variables de EVA del dolor, escalas funcionales y nivel de satisfacción personal. RESULTADOS: Contamos con 52 pacientes, 36 pacientes masculinos y 16 femeninos. La valoración del dolor con EVA 5.75 pasó a 0.98; la valoración funcional mediante una escala AOFAS preoperatoria 73.65 puntos aumentó a 92.98 puntos y la escala SFMCP preoperatoria de 72.44 puntos subió a 95.48 puntos y 23 pacientes (44.23%) regresaron a realizar al mismo nivel previo a la lesión actividad deportiva dentro de cuatro a siete meses posteriores a la cirugía. CONCLUSIONES: El tratamiento artroscópico del pinzamiento anterior de tobillo mostró mejoría significativa a 12 meses de seguimiento. La reincorporación a la actividad deportiva al mismo nivel previo a la lesión fue de cuatro a siete meses.

[Identification by images of the patient with diabetic foot of the type of injuries that required or will require amputation]. / Identificación por imágenes del paciente con pie diabético del tipo de lesiones que requirieron o requerirán amputación.

INTRODUCTION: Diabetes is a chronic-degenerative disease that develops after pancreatic dysfunction. An estimated 422 million people in the world are currently diagnosed with diabetes. One of its most common complications is diabetic foot. It is estimated that about 15% of diabetic patients will have lower extremities ulcers. MATERIAL AND METHODS: It is an observational, descriptive, prospective and cross-sectional study. It aims to know what the initial injuries that triggered an amputation in a complicated diabetic foot. Patients were presented with clinical photographs with images typical of pathologies for recognition. RESULTS: A total of 50 patients were included between January 2017 and July 2019. Of these 78% (38) patients were male, 22% (11) female. 22 patients (44%) recognized as the onset of diabetic foot an ulcer, 13 with blisters (26%), 10 with hyperkeratosis (20%), 5 with hammer toes (10%). CONCLUSIONS: 96% of patients were able to identify at least one injury as a predisposing factor for the onset of their complicated diabetic foot. The presentation of clinical photographs proved to be a patient-accepted tool. By identifying their initial injury we can determine which injury and where, where, it gave rise to the complication that led them to amputation. This information can help to perform preventive measures to limit amputations in the pelvic limbs of diabetic patients.

INTRODUCCIÓN: La diabetes es una enfermedad crónico degenerativa que se desarrolla posterior a una disfunción del páncreas. Se estima que actualmente hay 422 millones de personas en el mundo que cuentan con el diagnóstico de diabetes. Una de sus complicaciones más frecuentes es el pie diabético. Se estima que alrededor de 15% de los pacientes diabéticos tendrán úlceras en las extremidades inferiores. MATERIAL Y MÉTODOS: Es un estudio observacional, descriptivo, prospectivo y transversal. Su objetivo es conocer cuáles son las lesiones iniciales que desencadenaron una amputación en un pie diabético complicado. A los pacientes se les mostraron fotografías clínicas con las imágenes típicas de las patologías para su reconocimiento. RESULTADOS: Se incluyó un total de 50 pacientes entre Enero de 2017 y Julio de 2019. De éstos, 78% (38) pacientes fueron masculinos, 22% (11) femeninos. 22 pacientes (44%) reconocieron el inicio del pie diabético con una úlcera, 13 con flictenas (26%), 10 con hiperqueratosis (20%), cinco con dedos en martillo (10%). CONCLUSIONES: 96% de los pacientes lograron identificar al menos una lesión como factor predisponente para la aparición de pie diabético complicado. La presentación de fotografías clínicas resultó ser una herramienta aceptada por los pacientes. Mediante la identificación de su lesión inicial podemos determinar qué lesión y en qué sitio dio origen a la complicación que los llevó a la amputación. Esta información puede contribuir a tomar medidas preventivas para limitar las amputaciones en los miembros pélvicos de los pacientes diabéticos.

Effect of the degree of oxidation of graphene oxide on As(III) adsorption.

The study of the interaction between graphene oxide (GO) and arsenic is of great relevance not only in the design of adsorbent materials to remove this contaminant but also in the understanding of its combined nanotoxicity. In this work, we show that As(III) adsorption, primarily H3AsO3, by graphene oxide is affected by its degree of oxidation. Three types of GO with C/O ratios between 1.35 and 1.98 were produced, resulting in important variations in the concentration of COH and COC functional groups. The less oxidized material reached a maximum As(III) adsorption capacity of 123 mg/g, whereas the GO with the highest degree of oxidation reached a value of 288 mg/g at pH 7, the highest reported in the literature. We also show that sulfates and carbonates present in water strongly inhibit As(III) adsorption. The interaction between graphene oxide and As(III) was also studied by Density Functional Theory (DFT) computer models showing that graphene oxide interacts with As(III) primarily through hydrogen bonds, having interaction energies with the hydroxyl and epoxide groups of 1508.6 and 1583.6 kJ/mol, respectively. Finally, cytotoxicity tests showed that the graphene oxide maintained cellular viability of 57% with 50 µg/ml, regardless of its degree of oxidation.