Biofilms as promoters of bacterial antibiotic resistance and tolerance

Multidrug resistant bacteria are a global threat for human and animal health. However, they are only part of the problem of antibiotic failure. Another bacterial strategy that contributes to their capacity to withstand antimicrobials is the formation of biofilms. Biofilms are associations of microorganisms embedded a self-produced extracellular matrix. They create particular environments that confer bacterial tolerance and resistance to antibiotics by different mechanisms that depend upon factors such as biofilm composition, architecture, the stage of biofilm development, and growth condi-tions. The biofilm structure hinders the penetration of antibiotics and may prevent the accumulation of bactericidal concentrations throughout the entire biofilm. In addition, gradients of dispersion of nutrients and oxygen within the biofilm generate different metabolic states of individual cells and favor the development of antibiotic tolerance and bacterial persistence. Furthermore, antimicrobial resistance may develop within biofilms through a variety of mechanisms. The expression of efflux pumps may be induced in various parts of the biofilm and the mutation frequency is induced, while the presence of extracellular DNA and the close contact between cells favor horizontal gene transfer. A deep understanding of the mechanisms by which biofilms cause tolerance/resistance to antibiotics helps to develop novel strategies to fight these infections

Effect of abutment angulation in the retention and durability of three overdenture attachment systems: An in vitro study

PURPOSE. This in vitro study investigated and compared the durability and retention of three types of attachments. MATERIALS AND METHODS. Three commercially available attachments were investigated: Clix (R), Dalbo-Plus (R) and Locator (R). In total, 72 samples of these attachments were placed in the acrylic resin forms and subjected to mechanical testing (5400 cycles of insertion and removal) over the respective ball or Locator abutments immersed in artificial saliva at pH 7 and 37 degrees C. The abutments were placed at angulations of 0 degrees, 10 degrees and 20 degrees. The retention force was recorded at the beginning and after 540, 1080, 2160, 3240, 4320 and 5400 insertion-removal cycles. RESULTS. The results revealed that there were significant differences in the average values of the insertion/removal force due to angulation (F ((2.48)) = 343619, P<.05) and the type of attachment (F ((7.48)) = 23.220, P<.05). CONCLUSION. Greater angulation of the abutments was found to influence the retention capacity of the attachments, and the fatigue test simulating 5 years of denture insertion and removal did not produce wear in the metal abutments.info:eu-repo/semantics/publishedVersio

Superficial radiotherapy as haemostatic treatment in breast cancer

Poster Session [EP-1661] Purpose or Objective Breast cancer is a common pathology in which o = 25% in tumor size and absence of bleeding was observed. Conclusion Surface radiotherapy is a treatment modality that should be taken into account in patients with breast cancer who present bleeding as a consequence of local tumor growth, given that this is a treatment comfortable for the patient, non invasive and increases the quality of patient’s life

Presión intraabdominal y empeoramiento de la función renal durante las descompensaciones de la insuficiencia cardiaca. Un informe preliminar del estudio PIA.

Antecedentes: El aumento de la presión intraabdominal (PIA) que tiene lugar durante la insuficiencia cardiaca aguda parece estar directamente relacionado con un empeoramiento de la función renal, lo que conduce a peores resultados clínicos. Nuestro objetivo fue analizar la relación entre la PIA y los determinantes de la función renal para la insuficiencia cardiaca aguda descompensada (ICAD) durante el ingreso en un pabellón de medicina interna convencional. Pacientes y métodos: Estudio descriptivo y prospectivo. Se incluyó a aquellos pacientes con una tasa de filtración glomerular > 30 mL/min/1,73 m2, dispuestos a participar en el estudio y que otorgaron su consentimiento informado. El protocolo (PI 15 0227) fue aprobado por el Comité de Ética de Aragón. Resultados: Presentamos los resultados de un análisis preliminar llevado a cabo con los primeros 28 pacientes incluidos en el estudio. Los pacientes se segregaron en 2 grupos según la mediana de la PIA, alta (PIA > 15 mmHg) y baja (PIA < 15 mmHg), medida durante las primeras 24 h tras el ingreso por ICAD. Cada grupo estuvo integrado por 14 pacientes. No hubo diferencias entre los grupos en cuanto a características clínicas de referencia, comorbilidades ni tratamiento. Los pacientes con PIA superior a los 15 mmHg presentaron una tasa de filtración glomerular basal significativamente baja (70,7 vs. 44,4 mL/min/1,73 m2 con p = 0,004; urea en sangre 36 vs. 83 mg/dL con p = 0,002; creatinina sérica 0,87 vs. 1,3 mg/dL con p = 0,004 y cistatina C 1,2 vs. 1,94 mg/dL con p = 0,002). Además, estos pacientes mostraron las concentraciones de ácido úrico más altas (5,7 vs. 8,0; p = 0,046), las de hemoglobina resultaron más bajas (11,7 vs. 10,5 g/L; p = 0,04) y la estancia hospitalaria más larga (6,5 vs. 9,6 días; p = 0,017). Conclusiones: El aumento de la PIA parece ser un hallazgo frecuente en pacientes ingresados por ICAD. Independientemente de la PIA, los pacientes comparten un perfil clínico similar, si bien el aumento de la PIA se asoció con un empeoramiento significativo de la función renal de referencia. Background: An increase in intraabdominal pressure (IAP) during acute heart failure, seems to be directly related to worsening renal function, which leads to worse clinical outcomes. We aimed to analyze the relationship between IAP and determinants of renal function during admission for acute decompensation of heart failure (ADHF) in a conventional Internal Medicine Ward. Patients and methods: Descriptive and prospective study. Patients admitted for ADHF with an estimated glomerular filtration rate > 30 mL/min/1.73 m2, willing to participate and who gave their informed consent were included. Ethics Committee of Aragon approved the protocol (PI 15 0227). Results: We hereby report the results of an interim analysis of the first 28 patients included. Patients were divided in 2 groups according to the median of IAP measured during the first 24 h after admission for ADHF, namely high IAP (IAP>15 mmHg) and low (IAP< 15 mmHg). Fourteen patients were included in each group. No differences were found in baseline clinical characteristics, comorbidities or treatment between both groups. Patients with IAP above 15 mmHg, showed a significant lower baseline estimated glomerular filtration rate (70.7 vs. 44.4 mL/min/1.73 m2 with p=0.004], blood urea 36 vs. 83 mg/dL with p=0.002]; serum creatinine 0.87 vs. 1.3 mg/dL with p=0.004 and cystatin C 1.2 vs. 1.94 mg/dL with p= 0.002. Additionally, these patients had higher uric acid (5.7 vs. 8.0, p=0.046), lower hemoglobin concentrations (11.7 vs. 10.5 g/L, p=0.04) and longer length of hospital stay (6.5 vs. 9.6 days, p=0.017). Conclusions: The increase in IAP seems to be a frequent finding in patients admitted for ADHF. Patients share similar clinical profile irrespective of IAP, although the increase in IAP is associated with a significant baseline impairment of renal function

Nivolumab en linfoma de Hodgkin recaído/refractario: experiencia en Aragón

PB-111 Introducción: En el linfoma de Hodgkin (LH) las alteraciones genéticas del cromosoma 9p24.1 de la célula de Reed-Sternberg, causan una sobreexpresión del ligando 1 de muerte programada (PDL-1), que conducen a una evasión del sistema inmune y resistencia terapéutica. Para pacientes refractarios primarios o que recaen después de un trasplante autólogo y de tratamiento con Brentuxumab, existen pocas posibilidades. Nivolumab es una opción para conseguir respuesta y poder realizar trasplante alogénico. Presentamos la experiencia de 4 casos clínicos de Aragón. Paciente y métodos: Caso 1: Varón de 69 años diagnosticado de LH celularidad mixta estadio IIIA en Junio de 2005. 1ª línea: ABVDx6 y radioterapia mediastínica con RC. 2ª línea: por recidiva cervical: Ifosfamida, Vinorelbina y Prednisona con RC. 3ª línea: afectación cervical y retoperitoneal: cisplatino, citarabina y dexametasona más radioterapia cervical con RC. 4ª línea: MOPPx4 y Rituximab Gemcitabina con RC. Autotrasplante en Noviembre de 2011 con RC. 5ª línea: por afectación cervical, retroperitoneal, esplénica e iliaco: Brentuximabx4 y por mala respuesta se añade Bendamustinax3 con RC. A los 4 meses recaída agresiva con amplia afectación ósea y esplénica. Se administra Nivolumab. Caso 2: Varón de 32 años con LH esclerosis nodular IIIB en 2015. Tratado en otro país con ABVDx6 con RC y recaída al año. Después BEACOPPx4, GEMOXx4 y DHAPx4 sin resultado. En nuestro país Brentuximabx4 con progresión. Se administra Nivolumab. Caso3: Varón de 56 años con LH esclerosis nodular IVsB, en Septiembre de 2017. 1ª línea: ABVDx3 y AVDx3 con refractariedad y neumonitis por Bleomicina.2ª línea:ESAHPx2 con persistencia y toxicidad. 3ª línea: Brentuximabx4 con RC, consolidando con Brentuximab- Bendamustinax4. Progresión posterior rápida. Se administra Nivolumab. Caso 4:varón de 32 años diagnosticado en Abril 2016 de LH depleción linfocítica IVB (ósea). 1ª línea:ABVDx6 con RC. Recaída Mayo 2018.2ª línea: ESHAPx2 con persistencia.3ª línea: Brentuximabx4 con progresión. Se administra Nivolumab. Resultados: En el caso 1 se consigue RC con ..

Catechol-O-Methyltransferase Expression and 2-Methoxyestradiol Affect Microtubule Dynamics and Modify Steroid Receptor Signaling in Leiomyoma Cells

CONTEXT: Development of optimal medicinal treatments of uterine leiomyomas represents a significant challenge. 2-Methoxyestradiol (2ME) is an endogenous estrogen metabolite formed by sequential action of CYP450s and catechol-O-methyltransferase (COMT). Our previous study demonstrated that 2ME is a potent antiproliferative, proapoptotic, antiangiogenic, and collagen synthesis inhibitor in human leiomyomas cells (huLM). OBJECTIVES: Our objectives were to investigate whether COMT expression, by the virtue of 2ME formation, affects the growth of huLM, and to explore the cellular and molecular mechanisms whereby COMT expression or treatment with 2ME affect these cells. RESULTS: Our data demonstrated that E(2)-induced proliferation was less pronounced in cells over-expressing COMT or treated with 2ME (500 nM). This effect on cell proliferation was associated with microtubules stabilization and diminution of estrogen receptor alpha (ERalpha) and progesterone receptor (PR) transcriptional activities, due to shifts in their subcellular localization and sequestration in the cytoplasm. In addition, COMT over expression or treatment with 2ME reduced the expression of hypoxia-inducible factor -1alpha (HIF-1 alpha) and the basal level as well as TNF-alpha-induced aromatase (CYP19) expression. CONCLUSIONS: COMT over expression or treatment with 2ME stabilize microtubules, ameliorates E(2)-induced proliferation, inhibits ERalpha and PR signaling, and reduces HIF-1 alpha and CYP19 expression in human uterine leiomyoma cells. Thus, microtubules are a candidate target for treatment of uterine leiomyomas. In addition, the naturally occurring microtubule-targeting agent 2ME represents a potential new therapeutic for uterine leiomyomas

Real-Time Imaging of HIF-1α Stabilization and Degradation

HIF-1α is overexpressed in many human cancers compared to normal tissues due to the interaction of a multiplicity of factors and pathways that reflect specific genetic alterations and extracellular stimuli. We developed two HIF-1α chimeric reporter systems, HIF-1α/FLuc and HIF-1α(ΔODDD)/FLuc, to investigate the tightly controlled level of HIF-1α protein in normal (NIH3T3 and HEK293) and glioma (U87) cells. These reporter systems provided an opportunity to investigate the degradation of HIF-1α in different cell lines, both in culture and in xenografts. Using immunofluorescence microscopy, we observed different patterns of subcellular localization of HIF-1α/FLuc fusion protein between normal cells and cancer cells; similar differences were observed for HIF-1α in non-transduced, wild-type cells. A dynamic cytoplasmic-nuclear exchange of the fusion protein and HIF-1α was observed in NIH3T3 and HEK293 cells under different conditions (normoxia, CoCl2 treatment and hypoxia). In contrast, U87 cells showed a more persistent nuclear localization pattern that was less affected by different growing conditions. Employing a kinetic model for protein degradation, we were able to distinguish two components of HIF-1α/FLuc protein degradation and quantify the half-life of HIF-1α fusion proteins. The rapid clearance component (t1/2 ∼4–6 min) was abolished by the hypoxia-mimetic CoCl2, MG132 treatment and deletion of ODD domain, and reflects the oxygen/VHL-dependent degradation pathway. The slow clearance component (t1/2 ∼200 min) is consistent with other unidentified non-oxygen/VHL-dependent degradation pathways. Overall, the continuous bioluminescence readout of HIF-1α/FLuc stabilization in vitro and in vivo will facilitate the development and validation of therapeutics that affect the stability and accumulation of HIF-1α

Mutations Associated with Acquired Resistance to PD-1 Blockade in Melanoma

BACKGROUND: Approximately 75% of objective responses to anti–programmed death 1 (PD-1) therapy in patients with melanoma are durable, lasting for years, but delayed relapses have been noted long after initial objective tumor regression despite continuous therapy. Mechanisms of immune escape in this context are unknown. METHODS: We analyzed biopsy samples from paired baseline and relapsing lesions in four patients with metastatic melanoma who had had an initial objective tumor regression in response to anti–PD-1 therapy (pembrolizumab) followed by disease progression months to years later. RESULTS: Whole-exome sequencing detected clonal selection and outgrowth of the acquired resistant tumors and, in two of the four patients, revealed resistance-associated loss-of-function mutations in the genes encoding interferon-receptor–associated Janus kinase 1 (JAK1) or Janus kinase 2 (JAK2), concurrent with deletion of the wild-type allele. A truncating mutation in the gene encoding the antigen-presenting protein beta-2-microglobulin (B2M) was identified in a third patient. JAK1 and JAK2 truncating mutations resulted in a lack of response to interferon gamma, including insensitivity to its antiproliferative effects on cancer cells. The B2M truncating mutation led to loss of surface expression of major histocompatibility complex class I. CONCLUSIONS: In this study, acquired resistance to PD-1 blockade immunotherapy in patients with melanoma was associated with defects in the pathways involved in interferon-receptor signaling and in antigen presentation. (Funded by the National Institutes of Health and others.