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1.
Eur J Gastroenterol Hepatol ; 36(1): 135-140, 2024 01 01.
Artículo en Inglés | MEDLINE | ID: mdl-37994620

RESUMEN

OBJECTIVES: Point shear-wave elastography (pSWE) alias acoustic radiation force impulse (ARFI) imaging is a well-established ultrasound-based technique for the non-invasive assessment of liver tissue stiffness. As cut-off values for liver cirrhosis cannot be transferred from one ultrasound system to another, this study aimed at determining cut-off values for the newly developed Siemens ACUSON Sequoia ultrasound system. METHODS: In a pilot study phase, two independent examiners conducted 10 pSWE measurements in an elasticity phantom and 32 healthy individuals for the determination of inter-examiner agreement. Afterwards, 22 cirrhotic patients and 57 patients with chronic liver disease undergoing liver biopsy underwent pSWE. Patient characteristics and stiffness values were compared for individuals with and without liver cirrhosis. Diagnostic accuracies of cut-off values for the diagnosis of liver cirrhosis were calculated using areas under the receiver operating characteristics analysis and Youden's index. In a subsequent validation study phase, these cut-off values were validated prospectively in 107 cirrhotic and 68 non-cirrhotic patients. RESULTS: Inter-examiner agreement was excellent for measurements in the elasticity phantom (intra-class correlation coefficient [ICC] = 0.998; P  < 0.001), and good for measurements in patients (ICC = 0.844; P  < 0.001). The best cut-off value for the diagnosis of liver cirrhosis was 1.405 m/s with an AUC of 0.872, a sensitivity of 88.2% and a specificity of 88.2% ( P  < 0.001). CONCLUSION: ARFI elastography using the Siemens ACUSON Sequoia showed a good inter-examiner agreement. The optimal cut-off value was lower than the cut-off values described for former generations of ultrasound devices. These preliminary results should be confirmed in larger patient collectives with histology as the reference standard.


Asunto(s)
Diagnóstico por Imagen de Elasticidad , Sequoia , Humanos , Diagnóstico por Imagen de Elasticidad/métodos , Proyectos Piloto , Cirrosis Hepática/complicaciones , Cirrosis Hepática/diagnóstico por imagen , Hígado/diagnóstico por imagen , Hígado/patología
2.
Nat Commun ; 12(1): 3733, 2021 Jun 18.
Artículo en Inglés | MEDLINE | ID: mdl-34145226

RESUMEN

Graphene integrated photonics provides several advantages over conventional Si photonics. Single layer graphene (SLG) enables fast, broadband, and energy-efficient electro-optic modulators, optical switches and photodetectors (GPDs), and is compatible with any optical waveguide. The last major barrier to SLG-based optical receivers lies in the current GPDs' low responsivity when compared to conventional PDs. Here we overcome this by integrating a photo-thermoelectric GPD with a Si microring resonator. Under critical coupling, we achieve >90% light absorption in a ~6 µm SLG channel along a Si waveguide. Cavity-enhanced light-matter interactions cause carriers in SLG to reach ~400 K for an input power ~0.6 mW, resulting in a voltage responsivity ~90 V/W, with a receiver sensitivity enabling our GPDs to operate at a 10-9 bit-error rate, on par with mature semiconductor technology, but with a natural generation of a voltage, rather than a current, thus removing the need for transimpedance amplification, with a reduction of energy-per-bit, cost, and foot-print.

3.
Eur Cell Mater ; 41: 558-575, 2021 05 22.
Artículo en Inglés | MEDLINE | ID: mdl-34021906

RESUMEN

Embryonic muscle forces are necessary for normal vertebral development and spinal curvature, but their involvement in intervertebral disc (IVD) development remains unclear. The aim of the current study was to determine how muscle contractions affect (1) notochord involution and vertebral segmentation, and (2) IVD development including the mechanical properties and morphology, as well as collagen fibre alignment in the annulus fibrosus. Muscular dysgenesis (mdg) mice were harvested at three prenatal stages: at Theiler Stage (TS)22 when notochord involution starts, at TS24 when involution is complete, and at TS27 when the IVD is formed. Vertebral and IVD development were characterised using histology, immunofluorescence, and indentation testing. The results revealed that notochord involution and vertebral segmentation occurred independently of muscle contractions between TS22 and TS24. However, in the absence of muscle contractions, we found vertebral fusion in the cervical region at TS27, along with (i) a displacement of the nucleus pulposus towards the dorsal side, (ii) a disruption of the structural arrangement of collagen in the annulus fibrosus, and (iii) an increase in viscous behaviour of the annulus fibrosus. These findings emphasise the important role of mechanical forces during IVD development, and demonstrate a critical role of muscle loading during development to enable proper annulus fibrosus formation. They further suggest a need for mechanical loading in the creation of fibre-reinforced tissue engineering replacement IVDs as a therapy for IVD degeneration.


Asunto(s)
Disco Intervertebral/fisiología , Músculos/fisiología , Notocorda/fisiología , Animales , Anillo Fibroso/metabolismo , Anillo Fibroso/fisiología , Colágeno/metabolismo , Matriz Extracelular/metabolismo , Matriz Extracelular/fisiología , Femenino , Disco Intervertebral/metabolismo , Degeneración del Disco Intervertebral/metabolismo , Degeneración del Disco Intervertebral/fisiopatología , Masculino , Ratones , Ratones Endogámicos C57BL , Músculos/metabolismo , Notocorda/metabolismo , Núcleo Pulposo/metabolismo , Núcleo Pulposo/fisiología
4.
Int J Colorectal Dis ; 35(7): 1221-1230, 2020 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-32307587

RESUMEN

PURPOSE: Anastomotic leakage constitutes a dreaded complication after colorectal surgery, leading to increased morbidity and mortality as well as prolonged hospitalization. Most leakages become clinically apparent about 8 days after surgery; however, early detection is quintessential to reduce complications and to improve patients' outcome. We therefore investigated the significance of specific protein expression profiles as putative biomarkers, indicating anastomotic leakage. METHODS: In this single-center prospective cohort study serum and peritoneal fluid samples-from routinely intraoperatively inserted drainages-of colorectal cancer patients were collected 3 days after colorectal resection. Twenty patients without anastomotic leakage and 18 patients with an anastomotic leakage and without other complications were included. Protein expression of seven inflammatory markers in serum and peritoneal fluid was assessed by multiplex ELISA and correlated with patients' clinical data. RESULTS: Monocyte chemoattractant protein 2 (CCL8/MCP-2), leukemia-inhibiting factor (LIF), and epithelial-derived neutrophil-activating protein (CXCL5/ENA-78) were significantly elevated in peritoneal fluid but not in serum samples from patients subsequently developing anastomotic leakage after colorectal surgery. No expressional differences could be found between grade B and grade C anastomotic leakages. CONCLUSION: Measurement 3 days after surgery revealed altered protein expression patterns of the inflammatory markers CCL8/MCP2, LIF, and CXCL5/ENA-78 in peritoneal fluid from patients developing anastomotic leakage after colorectal surgery. Further studies with a larger patient cohort with inclusion of different variables are needed to evaluate their potential as predictive biomarkers for anastomotic leakage.


Asunto(s)
Fuga Anastomótica , Neoplasias Colorrectales , Anastomosis Quirúrgica , Fuga Anastomótica/diagnóstico , Fuga Anastomótica/etiología , Biomarcadores , Quimiocina CCL8 , Quimiocina CXCL5 , Neoplasias Colorrectales/cirugía , Detección Precoz del Cáncer , Humanos , Factor Inhibidor de Leucemia , Estudios Prospectivos
5.
J Eur Acad Dermatol Venereol ; 33(7): 1281-1289, 2019 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-30811675

RESUMEN

BACKGROUND: Risk factors for primary non-melanoma skin cancer (NMSC) in organ transplant recipients (OTR) have been well described. Data for subsequent NMSC and dynamics in their occurrence in OTR are limited. OBJECTIVE: To study long-term risks of primary and subsequent NMSC and associated risk factors in OTR. METHODS: A retrospective single-centre cohort study analysing medical records from a dermato-oncological specialty clinic. RESULTS: Of 464 OTR 110 (23.7%) developed at least one, 73 (15.7%) two and 51 (11%) three NMSC during a median follow-up of 9.6 years. Cumulative incidences at 5, 10 and 15 years were 14.7%, 23.5% and 34.5% for the first and 75.8%, 86.5% and 93.3% for the second. Median time-to-diagnosis declined from 22 years (95% CI 19-25) to 2 years (1-3) and about 1 year (0-2) for the first, second and third NMSC. Risk for subsequent NMSC only partially related to risk factors for the primary NMSC. Histologic type of the first NMSC predicted subtype and time-to-diagnosis of the subsequent NMSC. CONCLUSIONS: A first post-transplant NMSC, particularly a SCC, confers a high risk for subsequent NMSC arising with accelerated dynamics. Risk-adapted dermato-oncologic surveillance is advisable for all OTR.


Asunto(s)
Carcinoma Basocelular/epidemiología , Carcinoma de Células Escamosas/epidemiología , Recurrencia Local de Neoplasia/epidemiología , Neoplasias Primarias Secundarias/epidemiología , Trasplante de Órganos , Neoplasias Cutáneas/epidemiología , Adulto , Carcinoma Basocelular/patología , Carcinoma de Células Escamosas/patología , Femenino , Alemania/epidemiología , Humanos , Incidencia , Masculino , Persona de Mediana Edad , Recurrencia Local de Neoplasia/patología , Neoplasias Primarias Secundarias/patología , Periodo Posoperatorio , Estudios Retrospectivos , Factores de Riesgo , Neoplasias Cutáneas/patología , Factores de Tiempo , Adulto Joven
6.
J Ophthalmic Inflamm Infect ; 8(1): 12, 2018 Aug 23.
Artículo en Inglés | MEDLINE | ID: mdl-30141181

RESUMEN

BACKGROUND: B cell depleting therapy is widely used for lymphoproliferative diseases and immune-mediated disorders, including mucous membrane pemphigoid. The latter is an autoimmune blistering disease affecting predominantly the mucosae potentially associated with devastating complications. METHODS: A 71-year-old patient with severe mucous membrane pemphigoid involving ocular, oral pharyngeal and laryngeal involvement is described. To control the disease, the patient was given rituximab therapy in combination with oral corticosteroids. He subsequently experienced an epithelial herpes simplex virus keratitis in one eye and 3 months later in his fellow eye. Topical treatment with ganciclovir resulted in prompt recovery. RESULTS: For the first time, a correlation between rituximab and bilateral epithelial herpes simplex virus keratitis is described. CONCLUSIONS: Although rituximab is a promising biologic agent for the treatment of autoimmune diseases, it bears the risk of reactivation of viral infections, including the onset of herpes simplex virus keratitis.

7.
Eur J Neurol ; 24(1): 53-57, 2017 01.
Artículo en Inglés | MEDLINE | ID: mdl-27647674

RESUMEN

BACKGROUND AND PURPOSE: To determine the rate of peri-interventional silent brain infarcts after left atrial appendage occlusion (LAAO). METHODS: In this prospective, uncontrolled single-center pilot study, consecutive patients with atrial fibrillation undergoing LAAO between July 2013 and January 2016 were included. The Amplatzer Cardiac Plug, WATCHMAN or Amulet device was used. A neurological examination and cranial magnetic resonance imaging (MRI) were performed within 48 h before and after the procedure. MRI was evaluated for new diffusion-weighted imaging (DWI) hyperintensities, cerebral microbleeds (CMBs) and white-matter lesions (WMLs). RESULTS: Left atrial appendage occlusion was performed in 21 patients (mean age, 73.2 ± 9.5 years). Main reasons for LAAO were previous intracerebral hemorrhage (n = 11) and major systemic bleeding (n = 6). No clinically overt stroke occurred peri-interventionally. After the intervention, one patient had a small cerebellar hyperintensity on DWI (4.8%; 95% confidence interval, 0.0-14.3) that was not present on the MRI 1 day before the procedure. Among 11 patients with available MRI just before LAAO, there were no significant changes in the number of CMBs and the severity of WMLs after LAAO. CONCLUSIONS: This study of peri-interventional MRI in LAAO suggests a low rate of silent peri-procedural infarcts in this elderly population. Confirmation in larger studies is needed.


Asunto(s)
Apéndice Atrial , Infarto Cerebral/epidemiología , Infarto Cerebral/etiología , Oclusión Terapéutica/efectos adversos , Anciano , Anciano de 80 o más Años , Fibrilación Atrial/complicaciones , Fibrilación Atrial/terapia , Hemorragia Cerebral/epidemiología , Hemorragia Cerebral/etiología , Imagen de Difusión por Resonancia Magnética , Femenino , Humanos , Masculino , Persona de Mediana Edad , Examen Neurológico , Proyectos Piloto , Estudios Prospectivos , Accidente Cerebrovascular/epidemiología , Accidente Cerebrovascular/etiología , Oclusión Terapéutica/estadística & datos numéricos , Resultado del Tratamiento , Sustancia Blanca/diagnóstico por imagen , Sustancia Blanca/patología
8.
Ann Rheum Dis ; 76(5): 802-810, 2017 May.
Artículo en Inglés | MEDLINE | ID: mdl-28007756

RESUMEN

The European League Against Rheumatism (EULAR) and the European Federation of National Associations of Orthopaedics and Traumatology (EFORT) have recognised the importance of optimal acute care for the patients aged 50 years and over with a recent fragility fracture and the prevention of subsequent fractures in high-risk patients, which can be facilitated by close collaboration between orthopaedic surgeons and rheumatologists or other metabolic bone experts. Therefore, the aim was to establish for the first time collaborative recommendations for these patients. According to the EULAR standard operating procedures for the elaboration and implementation of evidence-based recommendations, 7 rheumatologists, a geriatrician and 10 orthopaedic surgeons met twice under the leadership of 2 convenors, a senior advisor, a clinical epidemiologist and 3 research fellows. After defining the content and procedures of the task force, 10 research questions were formulated, a comprehensive and systematic literature search was performed and the results were presented to the entire committee. 10 recommendations were formulated based on evidence from the literature and after discussion and consensus building in the group. The recommendations included appropriate medical and surgical perioperative care, which requires, especially in the elderly, a multidisciplinary approach including orthogeriatric care. A coordinator should setup a process for the systematic investigations for future fracture risk in all elderly patients with a recent fracture. High-risk patients should have appropriate non-pharmacological and pharmacological treatment to decrease the risk of subsequent fracture.


Asunto(s)
Fracturas Osteoporóticas/terapia , Prevención Secundaria , Anciano , Anciano de 80 o más Años , Conservadores de la Densidad Ósea/uso terapéutico , Geriatría , Humanos , Persona de Mediana Edad , Planificación de Atención al Paciente , Grupo de Atención al Paciente , Educación del Paciente como Asunto , Atención Perioperativa , Medición de Riesgo
9.
Opt Express ; 24(15): 17041-9, 2016 Jul 25.
Artículo en Inglés | MEDLINE | ID: mdl-27464155

RESUMEN

We present the design simulation and characterization of a quantum cascade detector operating at 4.3µm wavelength. Array integration and packaging processes were investigated. The device operates in the 4.3µm CO2 absorption region and consists of 64 pixels. The detector is designed fully compatible to standard processing and material growth methods for scalability to large pixel counts. The detector design is optimized for a high device resistance at elevated temperatures. A QCD simulation model was enhanced for resistance and responsivity optimization. The substrate illuminated pixels utilize a two dimensional Au diffraction grating to couple the light to the active region. A single pixel responsivity of 16mA/W at room temperature with a specific detectivity D* of 5⋅107 cmHz/W was measured.

10.
J Cancer Res Clin Oncol ; 141(12): 2229-40, 2015 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-26253629

RESUMEN

PURPOSE: Adjuvant endocrine therapy (ET) is indicated in patients with steroid hormone receptor (HR)-positive breast cancer. The aim of this study was to evaluate the quality of HR determination and adjuvant endocrine treatment of breast cancer patients in a large cohort of more than 7000 women by analyzing data from a population-based regional cancer registry. METHODS: Data from the Clinical Cancer Registry Regensburg (Bavaria, Germany) were analyzed. Female patients with primary, nonmetastatic invasive breast cancer who were diagnosed between 2000 and 2012 (n = 7421) were included. HR-status was available in 97.4 % (n = 7229) of the patients. This data set (n = 7229) was used for subsequent statistical analyses. RESULTS: Since 2009, almost a complete rate of 99.6 % of analyzed HR-status was achieved. In sum, 85.8 % of the patients (n = 6199) were HR-positive, whereas 14.2 % (n = 1030) were HR-negative. Overall, 85.3 % (n = 5285) of HR-positive patients received ET either alone or in combination with chemotherapy (CHT) and/or trastuzumab. The majority of premenopausal patients received CHT plus ET (716 patients, 52.3 %). In postmenopausal patients, the most frequent systemic therapy was ET alone (2670 patients, 55.3 %). Best overall survival (OS) was found in HER2-/HR-positive patients receiving CHT plus ET plus trastuzumab (7-year OS rate of 97.2 % in premenopausal patients versus 86.9 % in postmenopausal patients). Premenopausal patients had a reduced benefit from additional CHT than postmenopausal patients. Premenopausal patients receiving only ET had a 7-year OS rate of 95.3 % compared to 92.7 % of patients receiving CHT plus ET. In contrast, postmenopausal patients treated with CHT plus ET had a 7-year OS rate of 84.0 % in comparison with those patients receiving only ET with a 7-year OS rate of 81.7 %. CONCLUSIONS: Analysis of HR in patients with early breast cancer achieved a very high quality in recent years. The vast majority of HR-positive patients received ET, and this guideline-adherent use improved OS. Inverse effects of the CHT plus ET combination in premenopausal versus postmenopausal patients and a still existing minority of patients not receiving guideline-adherent treatment should be further investigated in future studies.


Asunto(s)
Inhibidores de la Aromatasa/uso terapéutico , Neoplasias de la Mama/tratamiento farmacológico , Carcinoma Ductal de Mama/tratamiento farmacológico , Carcinoma Lobular/tratamiento farmacológico , Sistema Endocrino/efectos de los fármacos , Receptores de Estrógenos/metabolismo , Receptores de Progesterona/metabolismo , Adulto , Anciano , Anciano de 80 o más Años , Biomarcadores de Tumor/metabolismo , Neoplasias de la Mama/mortalidad , Neoplasias de la Mama/patología , Carcinoma Ductal de Mama/mortalidad , Carcinoma Ductal de Mama/patología , Carcinoma Lobular/mortalidad , Carcinoma Lobular/patología , Estudios de Casos y Controles , Quimioterapia Adyuvante , Femenino , Estudios de Seguimiento , Alemania , Humanos , Técnicas para Inmunoenzimas , Persona de Mediana Edad , Clasificación del Tumor , Invasividad Neoplásica , Estadificación de Neoplasias , Posmenopausia , Premenopausia , Pronóstico , Receptor ErbB-2/metabolismo , Sistema de Registros , Tasa de Supervivencia , Adulto Joven
12.
Orthopade ; 43(3): 256-64, 2014 Mar.
Artículo en Alemán | MEDLINE | ID: mdl-24604157

RESUMEN

BACKGROUND: Rehabilitation of athletes following surgical interventions for shoulder injuries is of utmost importance for recovery and return to sport. OBJECTIVES: The aim was to determine adequate concepts for rehabilitation following shoulder surgery in athletes. METHODS: A selective literature search was carried out in PubMed and a review of the available concepts is given taking personal experiences as well as national and international recommendations into consideration. RESULTS: This article presents the basic principles of functional rehabilitation, the kinetic chain and the different phases in rehabilitation. Specific rehabilitation concepts and return to sport strategies following traumatic dislocation, superior labrum anterior to posterior (SLAP) lesions and rotator cuff tears are presented. There is little high-level scientific evidence available for the treatment of these patients and most concepts are based on clinical experience and expert opinion. CONCLUSION: Rehabilitation of athletes with shoulder injuries requires a broad consensus strategy with respect to the next steps. Individual concepts for rehabilitation should take surgical and patient-specific criteria into consideration. Further research is urgently required to develop evidence-based recommendations.


Asunto(s)
Traumatismos en Atletas/rehabilitación , Complicaciones Posoperatorias/rehabilitación , Lesiones del Hombro , Traumatismos en Atletas/fisiopatología , Traumatismos en Atletas/cirugía , Rendimiento Atlético/fisiología , Fenómenos Biomecánicos , Humanos , Inestabilidad de la Articulación/fisiopatología , Inestabilidad de la Articulación/rehabilitación , Inestabilidad de la Articulación/cirugía , Modalidades de Fisioterapia , Complicaciones Posoperatorias/fisiopatología , Equilibrio Postural/fisiología , Pronóstico , Recuperación de la Función , Manguito de los Rotadores/fisiopatología , Manguito de los Rotadores/cirugía , Lesiones del Manguito de los Rotadores , Hombro/fisiopatología , Hombro/cirugía , Luxación del Hombro/fisiopatología , Luxación del Hombro/rehabilitación , Luxación del Hombro/cirugía
15.
Acta Biomater ; 9(6): 6876-84, 2013 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-23415749

RESUMEN

Adipose-derived mesenchymal stem cells (adMSCs) exhibit a high angiogenic activity. Accordingly, their incorporation into tissue constructs represents a promising vascularization strategy in tissue engineering. In the present study, we analyzed whether the efficacy of this approach can be improved by seeding adMSCs as three-dimensional spheroids onto porous scaffolds. Green fluorescent protein (GFP)-positive adMSCs expressing CD13, CD73, CD90 and CD117 were isolated from C57BL/6-TgN(ACTB-EGFP)1Osb/J mice for the generation of spheroids using the liquid overlay technique. Porous polyurethane scaffolds were seeded with these spheroids or a comparable number of individual adMSCs and implanted into the dorsal skinfold chamber of C57BL/6 wild-type mice. The vascularization of the implants was analyzed and compared to non-seeded scaffolds by means of intravital fluorescence microscopy and immunohistochemistry. The adMSC spheroids exhibited a homogeneous diameter of ~270µm and could easily be incorporated into the scaffolds by dynamic seeding. After implantation, they induced a strong angiogenic host tissue response, resulting in an improved scaffold vascularization with a significantly higher functional microvessel density when compared to non-seeded scaffolds and scaffolds seeded with individual adMSCs. Immunohistochemical analyses revealed that a high fraction of ~40% of all microvessels within the center of spheroid-seeded scaffolds developed from GFP-positive adMSCs. These vessels inosculated with ingrowing GFP-negative vessels of the host. This indicates that adMSC spheroids serve as individual vascularization units, promoting the simultaneous development of new microvascular networks at different locations inside implanted tissue constructs. Thus, adMSC spheroids may be used to increase the efficacy of MSC-based vascularization strategies in future tissue engineering applications.


Asunto(s)
Adipocitos/citología , Vasos Sanguíneos/citología , Vasos Sanguíneos/crecimiento & desarrollo , Células Madre Mesenquimatosas/citología , Células Madre Mesenquimatosas/fisiología , Neovascularización Fisiológica/fisiología , Andamios del Tejido , Adipocitos/fisiología , Animales , Diferenciación Celular , Células Cultivadas , Diseño de Equipo , Análisis de Falla de Equipo , Ensayo de Materiales , Ratones , Ratones Endogámicos C57BL , Ratones Transgénicos , Poliuretanos/química , Porosidad , Esferoides Celulares/citología , Esferoides Celulares/fisiología , Ingeniería de Tejidos/instrumentación
16.
Eur Cell Mater ; 24: 266-77, 2012 Sep 24.
Artículo en Inglés | MEDLINE | ID: mdl-23007911

RESUMEN

In tissue engineering, the generation of tissue constructs comprising preformed microvessels is a promising strategy to guarantee their adequate vascularisation after implantation. Herein, we analysed whether this may be achieved by seeding porous scaffolds with adipose tissue-derived microvascular fragments. Green fluorescent protein (GFP)-positive microvascular fragments were isolated by enzymatic digestion from epididymal fat pads of male C57BL/6-TgN(ACTB-EGFP)1Osb/J mice. Nano-size hydroxyapatite particles/poly(ester-urethane) scaffolds were seeded with these fragments and implanted into the dorsal skinfold chamber of C57BL/6 wild-type mice to study inosculation and vascularisation of the implants by means of intravital fluorescence microscopy, histology and immunohistochemistry over 2 weeks. Empty scaffolds served as controls. Vital microvascular fragments could be isolated from adipose tissue and seeded onto the scaffolds under dynamic pressure conditions. In the dorsal skinfold chamber, the fragments survived and exhibited a high angiogenic activity, resulting in the formation of GFP-positive microvascular networks within the implants. These networks developed interconnections to the host microvasculature, resulting in a significantly increased functional microvessel density at day 10 and 14 after implantation when compared to controls. Immunohistochemical analyses of vessel-seeded scaffolds revealed that >90 % of the microvessels in the implants' centre and ~60 % of microvessels in the surrounding host tissue were GFP-positive. This indicates that the scaffolds primarily vascularised by external inosculation. These novel findings demonstrate that the vascularisation of implanted porous scaffolds can be improved by incorporation of microvascular fragments. Accordingly, this approach may markedly contribute to the success of future tissue engineering applications in clinical practice.


Asunto(s)
Tejido Adiposo/irrigación sanguínea , Regeneración Tisular Dirigida , Microvasos/crecimiento & desarrollo , Andamios del Tejido/química , Implantes Absorbibles , Tejido Adiposo/química , Animales , Masculino , Ratones , Ratones Endogámicos C57BL
17.
J. Public Health Africa (Online) ; 2(2): 102-107, 2011.
Artículo en Inglés | AIM (África) | ID: biblio-1263214

RESUMEN

Experience suggests that the incorporation of gender approaches into family planning (FP) and reproductive health (RH) programs may increase their impact and sustainability; but further work is needed to examine the interactions between gender norms and family planning and to incorporate this understanding into behavior change communication (BCC) in specific social contexts. We conducted open-ended; in-depth interviews with 30 young currently married men; 30 young married women and 12 older people who influenced FP decisions. Six focus group interviews were also conducted. The interviews focused on the role of gender norms in reproductive decision-making and contraceptive use among young married men and women in Tanzania. The findings suggest that gender factors; such as men's dominance in decision-making do function as barriers to the use of modern contraceptives; but that fear of side effects; by both men and women; may be even more important deterrents. Results from this research will inform the development of BCC interventions to be tested in a subsequent intervention study in which gender factors and poor information about contraceptive methods will be addressed


Asunto(s)
Toma de Decisiones , Servicios de Planificación Familiar , Identidad de Género , Investigación Cualitativa
18.
Eur Cell Mater ; 20: 356-66, 2010 Dec 10.
Artículo en Inglés | MEDLINE | ID: mdl-21154242

RESUMEN

The engineering of preformed microvessels offers the promising opportunity to rapidly vascularise implanted tissue constructs by the process of inosculation. Herein, we analyzed whether this process may further be accelerated by cultivation of prevascularised tissue constructs in Matrigel before implantation. Nano-size hydroxyapatite particles/poly(ester-urethane) scaffolds were implanted into the flank of FVB/N-TgN (Tie2/GFP) 287 Sato mice to allow the ingrowth of a granulation tissue with green fluorescent protein (GFP)-positive blood vessels. After harvesting, these prevascularised constructs were then transferred into dorsal skinfold chambers of FVB/N recipient mice to study the process of inosculation. The constructs were implanted directly after embedding in Matrigel or after 3 days of cultivation in the extracellular matrix. Matrigel-free constructs served as control. Cultivation in Matrigel resulted in the outgrowth of CD31/GFP-positive vascular sprouts. Vascularisation of these constructs was markedly improved when compared to the other two groups, as indicated by a significantly elevated functional microvessel density between days 6 to 14 after implantation into the dorsal skinfold chamber. This was associated with an increased number of GFP-positive blood vessels growing into the surrounding host tissue. Thus, the blood supply to prevascularised tissue constructs can be accelerated by their pre-cultivation in an angiogenic extracellular matrix, promoting external inosculation of the preformed microvascular networks with the host microvasculature.


Asunto(s)
Matriz Extracelular/trasplante , Microvasos/fisiología , Neovascularización Fisiológica , Tejido Subcutáneo/irrigación sanguínea , Animales , Colágeno , Combinación de Medicamentos , Durapatita , Hemodinámica , Implantes Experimentales , Laminina , Ratones , Poliésteres , Poliuretanos , Proteoglicanos , Andamios del Tejido
19.
Gut ; 58(10): 1399-409, 2009 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-19528037

RESUMEN

BACKGROUND: Although histone deacetylase inhibitors (HDACi) are promising cancer therapeutics regulating proliferation, differentiation and apoptosis, molecular pathways engaged by specific HDAC isoenzymes in cancer are ill defined. RESULTS: In this study we demonstrate that HDAC2 is highly expressed in pancreatic ductal adenocarcinoma (PDAC), especially in undifferentiated tumours. We show that HDAC2, but not HDAC1, confers resistance towards the topoisomerase II inhibitor etoposide in PDAC cells. Correspondingly, the class I selective HDACi valproic acid (VPA) synergises with etoposide to induce apoptosis of PDAC cells. Transcriptome profiling of HDAC2-depleted PDAC cells revealed upregulation of the BH3-only protein NOXA. We show that the epigenetically silenced NOXA gene locus is opened after HDAC2 depletion and that NOXA upregulation is sufficient to sensitise PDAC cells towards etoposide-induced apoptosis. CONCLUSIONS: In summary, our data characterise a novel molecular mechanism that links the epigenetic regulator HDAC2 to the regulation of the pro-apoptotic BH3-only protein NOXA in PDAC. Targeting HDAC2 will therefore be a promising strategy to overcome therapeutic resistance of PDAC against chemotherapeutics that induce DNA damage.


Asunto(s)
Carcinoma Ductal Pancreático/metabolismo , Histona Desacetilasas/fisiología , Proteínas de Neoplasias/fisiología , Neoplasias Pancreáticas/metabolismo , Proteínas Proto-Oncogénicas c-bcl-2/metabolismo , Proteínas Represoras/fisiología , Antineoplásicos Fitogénicos/farmacología , Carcinoma Ductal Pancreático/genética , Línea Celular Tumoral , Daño del ADN/genética , Resistencia a Antineoplásicos/genética , Inhibidores Enzimáticos/farmacología , Etopósido/farmacología , Perfilación de la Expresión Génica , Silenciador del Gen/fisiología , Histona Desacetilasa 2 , Histona Desacetilasas/genética , Humanos , Proteínas de Neoplasias/genética , Proteínas de Neoplasias/metabolismo , Neoplasias Pancreáticas/genética , Proteínas Proto-Oncogénicas c-bcl-2/genética , Proteínas Represoras/genética , Ácido Valproico/farmacología
20.
Phys Rev Lett ; 97(5): 050602, 2006 Aug 04.
Artículo en Inglés | MEDLINE | ID: mdl-17026090

RESUMEN

Using fluorescence spectroscopy we directly measure entropy production of a single two-level system realized experimentally as an optically driven defect center in diamond. We exploit a recent suggestion to define entropy on the level of a single stochastic trajectory [Seifert, Phys. Rev. Lett. 95, 040602 (2005)10.1103/PhysRevLett.95.040602]. Entropy production can then be split into one of the system itself and one of the surrounding medium. We demonstrate that the total entropy production obeys various exact relations for finite time trajectories.

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