RESUMEN
This consensus paper summarizes the expert consensus and recommendations of the working group "Heart and Kidney" of the German Cardiac Society (DGK) and the German Society of Nephrology (DGfN) on contrast medium-induced acute kidney injury. Potentially nephrotoxic contrast agents containing iodine are frequently used in interventional medicine and for computer tomography diagnostics. Acute kidney injury occurs in approximately 8-17% of patients exposed to contrast media. The risk factors and underlying pathophysiology are discussed and recommendations for the prophylaxis and treatment of contrast medium-induced acute nephropathy are presented.
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Lesión Renal Aguda/inducido químicamente , Medios de Contraste/toxicidad , Riñón/metabolismo , Nefrología/normas , Guías de Práctica Clínica como Asunto/normas , Lesión Renal Aguda/diagnóstico , Lesión Renal Aguda/prevención & control , Consenso , Medios de Contraste/administración & dosificación , Humanos , Factores de Riesgo , Sociedades MédicasRESUMEN
OBJECTIVE: To identify factors associated with short-term, intermediate and long-term outcome in patients with infective endocarditis (IE) and the need for treatment on intensive care unit (ICU). DESIGN AND SETTING: Retrospective analysis and long-term follow-up by questionnaire in the two medical ICUs of our university hospital. PATIENTS: We conducted a retrospective analysis of all consecutive patients with IE and need for ICU treatment in our department between 2002 and 2009. All patients fulfilled the modified Duke criteria for definite diagnosis of IE. MEASUREMENTS AND MAIN RESULTS: Data of 216 patients (aged 62 ± 14 years, 31 % female) were analyzed, 15.7 % of whom had prosthetic valve endocarditis. Infectious agent (IA) was identified in 74 % and surgery was performed in 57 %. 56 patients (24.9 %) died on ICU, 9 patients were sent to palliative care units and died several days later. During follow-up, another 44 patients died. Multivariate Cox-regression analysis identified the following independent risk factors: High initial SAPS II for 30d-, multiple organ failure and high maximum SAPS II for 100d- and high maximum leukocyte count for long-term mortality. Surgical intervention during ICU was an independent predictor of a better 30d outcome. CONCLUSIONS: In contrast to general IE populations, IA and the type of infected impaired valve are not main predictors of survival in critically ill IE-patients. Biomarker of acute infection and markers for severity of illness (scores and organ failure) are independent risk factors for mortality. The surgical clearance of infected valve, device or abscesses is an independent predictor of 30d outcome.
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Endocarditis/epidemiología , Unidades de Cuidados Intensivos , Adolescente , Adulto , Anciano , Anciano de 80 o más Años , Endocarditis/mortalidad , Femenino , Estudios de Seguimiento , Humanos , Masculino , Persona de Mediana Edad , Estudios Retrospectivos , Factores de Riesgo , Encuestas y Cuestionarios , Análisis de Supervivencia , Resultado del Tratamiento , Adulto JovenRESUMEN
We present a new method for the distinct specific chemical stimulation of single cells and small cell clusters within their natural environment. By single-drop release of chemical agents with droplets in size of typical cell diameters (d <30 µm) on-demand micro gradients can be generated for the specific manipulation of single cells. A single channel and a double channel agent release cartridge with integrated fluidic structures and integrated agent reservoirs are shown, tested, and compared in this publication. The single channel setup features a fluidic structure fabricated by anisotropic etching of silicon. To allow for simultaneous release of different agents even though maintaining the same device size, the second type comprises a double channel fluidic structure, fabricated by photolithographic patterning of TMMF. Dispensed droplet volumes are V = 15 pl and V = 10 pl for the silicon and the TMMF based setups, respectively. Utilizing the agent release cartridges, the application in biological assays was demonstrated by hormone-stimulated premature bud formation in Physcomitrella patens and the individual staining of one single L 929 cell within a confluent grown cell culture.
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Sistemas de Liberación de Medicamentos/instrumentación , Técnicas Analíticas Microfluídicas/instrumentación , Análisis de la Célula Individual/instrumentación , Bryopsida/citología , Bryopsida/efectos de los fármacos , Citocininas/farmacologíaRESUMEN
Biliary anastomotic strictures after liver transplantation are a major source of morbidity and graft failure; however, repeated endoscopic therapy has shown variable long-term success rates. Thus the aim of this prospective case series was to evaluate the safety and efficacy of using paclitaxel-eluting balloons in 13 patients requiring treatment for symptomatic anastomotic strictures following liver transplantation. Sustained clinical success-defined as no need for further endoscopic intervention for at least 6 months - was achieved in 12â/13 patients (92â%). One, two, and three interventions were required in 9 (69â%), 1, and 2 patients, respectively (mean number of sessions was 1.46). Mean (± SD) bilirubin level dropped from 6.8 (± 4.1) mg/dL to 1.4 (± 0.9) mg/dL. These promising results justify carrying out a randomized comparative trial to confirm this innovative approach.
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Colestasis/terapia , Trasplante de Hígado/efectos adversos , Paclitaxel/uso terapéutico , Stents , Adulto , Anastomosis Quirúrgica/efectos adversos , Anastomosis Quirúrgica/métodos , Colangiopancreatografia Retrógrada Endoscópica/métodos , Colestasis/etiología , Estudios de Cohortes , Constricción Patológica/diagnóstico por imagen , Constricción Patológica/etiología , Constricción Patológica/terapia , Dilatación/instrumentación , Dilatación/métodos , Femenino , Alemania , Humanos , Trasplante de Hígado/métodos , Masculino , Persona de Mediana Edad , Complicaciones Posoperatorias/fisiopatología , Complicaciones Posoperatorias/terapia , Pronóstico , Estudios Prospectivos , Medición de Riesgo , Resultado del TratamientoRESUMEN
Success of human myocardial tissue engineering for cardiac repair has been limited by adverse effects of scaffold materials, necrosis at the tissue core, and poor survival after transplantation due to ischemic injury. Here, we report the development of scaffold-free prevascularized human heart tissue that survives in vivo transplantation and integrates with the host coronary circulation. Human embryonic stem cells (hESCs) were differentiated to cardiomyocytes by using activin A and BMP-4 and then placed into suspension on a rotating orbital shaker to create human cardiac tissue patches. Optimization of patch culture medium significantly increased cardiomyocyte viability in patch centers. These patches, composed only of enriched cardiomyocytes, did not survive to form significant grafts after implantation in vivo. To test the hypothesis that ischemic injury after transplantation would be attenuated by accelerated angiogenesis, we created "second-generation," prevascularized, and entirely human patches from cardiomyocytes, endothelial cells (both human umbilical vein and hESC-derived endothelial cells), and fibroblasts. Functionally, vascularized patches actively contracted, could be electrically paced, and exhibited passive mechanics more similar to myocardium than patches comprising only cardiomyocytes. Implantation of these patches resulted in 10-fold larger cell grafts compared with patches composed only of cardiomyocytes. Moreover, the preformed human microvessels anastomosed with the rat host coronary circulation and delivered blood to the grafts. Thus, inclusion of vascular and stromal elements enhanced the in vitro performance of engineered human myocardium and markedly improved viability after transplantation. These studies demonstrate the importance of including vascular and stromal elements when designing human tissues for regenerative therapies.
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Miocitos Cardíacos/trasplante , Trasplante de Células Madre/métodos , Animales , Diferenciación Celular , Células Madre Embrionarias/citología , Células Madre Embrionarias/trasplante , Femenino , Humanos , Miocardio/citología , Miocitos Cardíacos/citología , Ratas , Ratas Sprague-Dawley , Ingeniería de Tejidos/métodos , Andamios del TejidoRESUMEN
Guidelines on opioid therapy for patients with chronic non-tumor pain should support pain relief, prevent iatrogenic suffering, collateral health damage and legal restrictions on the availability of opioid analgesics. A total of six North American and two European committees recently developed guidelines which differ from the previous ones by being based on many more randomized controlled trials. In anticipation of lower analgesic effects than are to be expected from solely consensus-based guidelines, they recommended a more thorough control of individual therapeutic opioid trials than before. Drafting recommendations for a preferably individual efficacy prognosis is a further objective of the guidelines. This article will discuss if previous and current recommendations of opioid guidelines meet these requirements.
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Analgésicos Opioides/uso terapéutico , Neoplasias/complicaciones , Dolor/tratamiento farmacológico , Dolor/etiología , Enfermedad Aguda , Analgésicos Opioides/administración & dosificación , Consenso , Medicina Basada en la Evidencia , Guías como Asunto , Humanos , Medicina de Precisión , Ensayos Clínicos Controlados Aleatorios como AsuntoRESUMEN
The hypertensive emergency situation is characterized by an acute-mostly life-threatening-blood pressure derailment with the risk of acute end organ damage. It is an acute manifestation of arterial hypertension, which manifests in a variety of symptoms. The etiology is in most cases long-term (chronic) hypertension as a result of low compliance or inadequate antihypertensive therapy. It can also occur as a first manifestation of arterial hypertension. It requires timely antihypertensive drug therapy, which should be initiated in an intensive or intermediate care unit. The choice of antihypertensive therapy regimen should be based on the underlying end organ damage. Fast-acting, easily controllable and intravenously administered substances should be preferred. The most commonly used substances (groups) are urapidil, nitroglycerin, beta blockers and short-acting calcium channel blockers. With a few exceptions, a deliberate, rapid reduction in blood pressure of no more than 20-25% of the initial value is sufficient for extracerebral causes. A subsequent systolic blood pressure target of 160/100â¯mmâ¯Hg should be aimed for within the next 2-6â¯h. An overly rapid drop in blood pressure can lead to reduced blood flow to the central nervous system due to changes in autoregulation. Exceptions to this rule are acute aortic dissection and flash pulmonary edema-in these cases, prompt blood pressure normalization should be achieved. The initial acute therapy should be followed by a more detailed investigation of the cause and a long-term therapy setting based on this.
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Hipertensión , Administración del Tratamiento Farmacológico , Antagonistas Adrenérgicos beta , Antihipertensivos/efectos adversos , Presión Sanguínea , Humanos , Hipertensión/tratamiento farmacológicoRESUMEN
BACKGROUND AND AIMS: The prevalence of lower extremity artery disease (LEAD) is increasing worldwide and sex-related differences are a current matter of debate. METHODS: We analysed claims data on unselected patients with in-patient treatment for LEAD with intermittent claudication (IC; Rutherford grade 1-3) from 01.01.2014 to 31.12.2015. Data files included diagnostic and procedural information from two years before index, and a five-year follow-up. RESULTS: Our analysis comprised 42,197 IC patients, thereof 28,520 (68%) male. Male patients were younger (median: 66.4 years vs. 72.6 years) but presented with higher frequency of cardiovascular risk factors such as diabetes (40% female vs. 46% male), atrial fibrillation (13% vs. 17%), chronic coronary syndrome (41% vs. 53%), chronic heart failure (23% vs. 27%), or chronic kidney disease (29% vs. 32%; all p < 0.001; age adjusted). Revascularisation applied in 80% of patients, thereof endovascular approach predominantly in female and surgery in male patients. Concomitant pharmacotherapy with statins (74% at 2 years) and platelet inhibitors (75% respectively) were long lasting below guideline recommendation, under-use being more pronounced in women. Two years after index, one-third of IC patients had subsequent revascularisation, one-quarter progressed to chronic limb threatening ischemia (CLTI), and 2% underwent amputation. Male sex was an independent risk factor for long-term mortality (female HR 0.75; 95%-CI 0.72-0.79; p < 0.001) and CLTI (female HR 0.89; 95%-CI 0.86-0.92; p < 0.001) during follow-up. CONCLUSIONS: The majority of in-patient treated patients for IC are male, presenting with worse cardiovascular risk profiles. In view of a general under-supply with statins and platelet inhibitors, women received somewhat less often preventive medication. Despite low LEAD stages at index, serious prognosis was observed in the long term. Particularly male patients were at high risk for all-cause mortality and the combined endpoint CLTI and death.
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Procedimientos Endovasculares , Enfermedad Arterial Periférica , Anciano , Amputación Quirúrgica , Femenino , Humanos , Claudicación Intermitente/diagnóstico , Claudicación Intermitente/epidemiología , Claudicación Intermitente/terapia , Isquemia , Extremidad Inferior , Masculino , Enfermedad Arterial Periférica/diagnóstico , Enfermedad Arterial Periférica/epidemiología , Enfermedad Arterial Periférica/terapia , Factores de Riesgo , Resultado del TratamientoRESUMEN
Routine well-child visits, implemented as a means of secondary prevention and covered by health insurance, lead to early identification of disorders and abnormalities in child development."Guiding principles for children" (by the G-BA) have determined the content of the eleven examinations, ranging from U1 immediately after birth to J1 in adolescence; eight of them take place within the first four years of age. Since cases of child maltreatment, neglect, or abuse became public in 2007, almost all German federal states have established mandatory examination and notification processes in the new child welfare surveillance programs. First results in the German federal states (six of which are exemplarily illustrated) point out that mandatory requirements have collectively increased the frequency of medical check-ups in children, especially starting from four years of age and most significantly in families with social disadvantages (young/single parents, immigrant background, uneducated or socially disadvantaged families), which have so far been difficult to reach. Subsequently, provision of primary prevention (vaccinations and health promotion advice) by pediatricians has also increased. As a sole instrument for the complete identification of threats for children's welfare, however, systems inviting and reminding parents about check-ups are only of limited benefit.
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Maltrato a los Niños/diagnóstico , Maltrato a los Niños/prevención & control , Protección a la Infancia , Examen Físico/estadística & datos numéricos , Examen Físico/normas , Adolescente , Niño , Maltrato a los Niños/legislación & jurisprudencia , Femenino , Alemania/epidemiología , Humanos , Relaciones Interinstitucionales , MasculinoRESUMEN
There is strong interaction between heart and kidneys in human beings. Both organs work together in many regulation mechanisms. Thus, heart failure leads in many cases to renal failure due to hemodynamic or hormonal feed-back mechanisms. Vice versa, chronic kidney disease turned out as a major and independent cardiovascular risk factor. Patients who suffer from both heart disease and chronic kidney disease are threatened from a very high morbidity and mortality. Moreover, the number of affected patients has doubled every 8-10 years--a dramatic trend which is ongoing. In many patients suffering from heart and chronic kidney disease, an under-use of cardiologic diagnostics as well as therapies has to be observed due to fears about adverse effects, which further enhances their worse prognosis.
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Cardiopatías/diagnóstico , Cardiopatías/terapia , Fallo Renal Crónico/diagnóstico , Fallo Renal Crónico/terapia , Cardiopatías/complicaciones , Humanos , Fallo Renal Crónico/etiologíaRESUMEN
Skeletal myoblasts form grafts of mature muscle in injured hearts, and these grafts contract when exogenously stimulated. It is not known, however, whether cardiac muscle can form electromechanical junctions with skeletal muscle and induce its synchronous contraction. Here, we report that undifferentiated rat skeletal myoblasts expressed N-cadherin and connexin43, major adhesion and gap junction proteins of the intercalated disk, yet both proteins were markedly downregulated after differentiation into myo-tubes. Similarly, differentiated skeletal muscle grafts in injured hearts had no detectable N-cadherin or connexin43; hence, electromechanical coupling did not occur after in vivo grafting. In contrast, when neonatal or adult cardiomyocytes were cocultured with skeletal muscle, approximately 10% of the skeletal myotubes contracted in synchrony with adjacent cardiomyocytes. Isoproterenol increased myotube contraction rates by 25% in coculture without affecting myotubes in monoculture, indicating the cardiomyocytes were the pacemakers. The gap junction inhibitor heptanol aborted myotube contractions but left spontaneous contractions of individual cardiomyocytes intact, suggesting myotubes were activated via gap junctions. Confocal microscopy revealed the expression of cadherin and connexin43 at junctions between myotubes and neonatal or adult cardiomyocytes in vitro. After microinjection, myotubes transferred dye to neonatal cardiomyocytes via gap junctions. Calcium imaging revealed synchronous calcium transients in cardiomyocytes and myotubes. Thus, cardiomyocytes can form electromechanical junctions with some skeletal myotubes in coculture and induce their synchronous contraction via gap junctions. Although the mechanism remains to be determined, if similar junctions could be induced in vivo, they might be sufficient to make skeletal muscle grafts beat synchronously with host myocardium.
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Músculo Esquelético/metabolismo , Infarto del Miocardio/fisiopatología , Miocardio/metabolismo , Cicatrización de Heridas/fisiología , Animales , Cadherinas/metabolismo , Calcio/metabolismo , Adhesión Celular/fisiología , Células Cultivadas , Conexina 43/metabolismo , Técnica del Anticuerpo Fluorescente , Uniones Comunicantes/metabolismo , Histocitoquímica , Microscopía Fluorescente , Contracción Muscular , Miocardio/patología , Ratas , Ratas Endogámicas F344 , TrasplantesRESUMEN
The German Society for the Study of Pain (DGSS) commissioned a meta-analytic review of the evidence on the long-term effects of opioids, non-opioid analgesics and cognitive- behavioral procedures for chronic non-cancer pain. A multidisciplinary expert panel was established to review the evidence and formulate recommendations as far as possible on the basis of means, standard deviations and group sizes from randomized controlled trials. Effect size estimates of analgesic effects (SMDs, WMDs) from studies were below clinical significance, whenever the reported data permitted evaluation and nearly equal for all the investigated medical therapies and pain syndromes. Therefore, the LONTS guidelines focus on the prevention of adverse effects and misuse and a multidisciplinary approach for the treatment of chronic pain is strongly recommended. Principles of opioid prescription and on the management of risks associated with the long-term use of opioids are described.
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Analgésicos Opioides/administración & dosificación , Dolor Intratable/tratamiento farmacológico , Analgésicos Opioides/efectos adversos , Antiinflamatorios no Esteroideos/administración & dosificación , Antiinflamatorios no Esteroideos/efectos adversos , Terapia Cognitivo-Conductual , Terapia Combinada , Alemania , Humanos , Cuidados a Largo Plazo , Neoplasias/fisiopatología , Dimensión del Dolor/efectos de los fármacos , Grupo de Atención al Paciente , Resultado del TratamientoRESUMEN
Local activation of the components of the renin angiotensin system in the heart is regarded as an important modulator of cardiac phenotype and function; however, little is known about their presence, regulation, and potential activation in the human heart. To investigate the gene expression of major angiotensin-II-forming enzymes in left ventricles of normal (n = 9) and failing human hearts (n = 20), we established a competitive RNA-polymerase chain reaction (PCR) for mRNA quantification of angiotensin-I converting enzyme (ACE) and human heart chymase. For each gene, competitor RNA targets with small internal deletions were used as internal standards to quantify the original number of transcripts and to control reverse transcription and PCR. In PCR, each target and the corresponding competitor were amplified by competing for the same primer oligonucleotides. The variability of ACE RNA-PCR was 11% indicating a high reproducibility of this method. In addition, ACE mRNA levels obtained by competitive RNA-PCR correlated favorably with traditional slot blot hybridization (r = 0.69, n = 10; P < 0.05). Compared with nonfailing hearts, the number of ACE transcripts referred to 100 ng of total RNA was increased threefold in patients with chronic heart failure (4.2 +/- 2.5 vs. 12.8 +/- 6 x 10(5); P < 0.0005). In contrast, no significant difference was found in chymase gene expression between normal and failing hearts. Thus, the expression of the cardiac ACE but not of human heart chymase is upregulated in failing human heart indicating an activation of the cardiac renin-angiotensin system in patients with advanced heart failure.
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Regulación Enzimológica de la Expresión Génica , Insuficiencia Cardíaca/enzimología , Miocardio/enzimología , Peptidil-Dipeptidasa A/genética , Reacción en Cadena de la Polimerasa , Adulto , Secuencia de Bases , Quimasas , Femenino , Humanos , Masculino , Persona de Mediana Edad , Datos de Secuencia Molecular , ARN Mensajero/análisis , Serina Endopeptidasas/genéticaRESUMEN
The negative correlation between coronary heart disease and plasma levels of HDL has been attributed to the ability of HDL to take up cellular cholesterol. The HDL3-induced removal of cellular cholesterol was reported to be impaired in fibroblasts from patients with familial HDL deficiency (Tangier disease, TD). In addition, we have recently shown that HDL3 stimulates the hydrolysis of phosphatidylcholine (PC) in cholesterol-loaded fibroblasts. To investigate whether this cell signaling pathway is involved in cholesterol efflux mechanisms, we compared the HDL3-induced PC hydrolysis in normal fibroblasts and in fibroblasts from a TD kindred, in whom the HDL3- and apolipoprotein A-I (apo A-I)-induced mobilization of cellular cholesterol was found to be reduced by 50%. The HDL3-induced formation of phosphatidic acid (PA) via PC-specific phospholipase D (PC-PLD) was markedly reduced by 60-80% in these cells, whereas the formation of diacylglycerol (DG) via PC-specific phospholipase C (PC-PLC) was two- to threefold enhanced. Defective regulation of PC-PLC and PC-PLD was similarly observed in response to apo A-I and endothelin, but not in response to the receptor-independent stimulation of PC hydrolysis by PMA. A Tangier-like PA and DG formation pattern could be induced in normal cells after preincubation with pertussis toxin, suggesting the involvement of a G-protein. The impaired mobilization of radiolabeled cellular cholesterol in TD cells could completely be overcome by increasing the PA levels in the presence of the PA phosphohydrolase inhibitor propranolol. Conversely, the inhibition of PA formation in the presence of 0.3% butanol as well as the inhibition of DG formation in the presence of the PC-PLC inhibitor D 609 reduced the mobilization of cellular cholesterol both in normal and in TD cells. Our data indicate that the coordinate formation of PA and DG via PC-PLD and PC-PLC is essential for efficient cholesterol efflux. The molecular defect in this TD kindred appears to affect an upstream effector of protein kinase C responsible for the G-protein-dependent regulation of PC-specific phospholipases.
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Fosfatidilcolinas/metabolismo , Fosfolipasa D/genética , Fosfolipasa D/fisiología , Transducción de Señal/genética , Transducción de Señal/fisiología , Enfermedad de Tangier/genética , Enfermedad de Tangier/metabolismo , Fosfolipasas de Tipo C/genética , Fosfolipasas de Tipo C/fisiología , Apolipoproteína A-I/metabolismo , Apolipoproteína A-I/farmacología , Hidrocarburos Aromáticos con Puentes/farmacología , Butanoles/farmacología , Células Cultivadas , Diglicéridos/metabolismo , Endotelinas/farmacología , Femenino , Fibroblastos/metabolismo , Proteínas de Unión al GTP/fisiología , Humanos , Lipoproteínas HDL/análisis , Lipoproteínas HDL/metabolismo , Masculino , Persona de Mediana Edad , Norbornanos , Linaje , Ácidos Fosfatidicos/metabolismo , Inhibidores de Fosfodiesterasa/farmacología , Fosfolipasa D/metabolismo , Propranolol/farmacología , Tiocarbamatos , Tionas/farmacología , Fosfolipasas de Tipo C/metabolismoRESUMEN
A mathematical approach developed to correct depth profiles of wet-chemically modified polymer films obtained by confocal Raman microscopy is presented which takes into account scattered contributions originated from a diffraction-limited laser focal volume. It is demonstrated that the problem can be described using a linear Fredholm integral equation of the first kind which correlates apparent and true Raman intensities with the depth resolution curve of the instrument. The calculations of the corrected depth profiles show that considerable differences between apparent and corrected depth profiles exist at the surface, especially when profiles with strong concentration gradients are dealt with or an instrument with poor depth resolution is used. Degrees of modification at the surface obtained by calculation of the corrected depth profiles are compared with those measured by FTIR-ATR and show an excellent concordance.
RESUMEN
The vision of multianalyte point-of-care diagnostics (POCT) is a handheld device that every patient can use easily for continuous monitoring of, for example, drug efficiency in the treatment of chronic diseases. Technologies are needed to realise this vision. Some are described here in the prototyping and industrial production of a disposable chip for the Micro-Tele-BioChip (muTBC) platform. muTBC is a technology platform that can be customised to meet specific requirements in drug safety and POCT.
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Miniaturización , Monitoreo Fisiológico/instrumentación , Quimioterapia , Alemania , Humanos , Sistemas de Atención de Punto , Resultado del TratamientoRESUMEN
BACKGROUND: Cardiomyocyte grafting augments myocyte numbers in the heart. We investigated (1) how developmental stage influences graft survival; (2) whether acutely necrotic or healing cardiac lesions support grafts; and (3) the differentiation and integration of cardiomyocyte grafts in injured hearts. METHODS AND RESULTS: Cardiomyocytes from fetal, neonatal, or adult inbred rats were grafted into normal myocardium, acutely cryoinjured myocardium, or granulation tissue (6 days after injury). Adult cardiomyocytes did not survive under any conditions. In contrast, fetal and neonatal cardiomyocytes formed viable grafts under all conditions. Time-course studies with neonatal cardiomyocytes showed that the grafts recapitulated many aspects of normal development. The adherens junction protein N-cadherin was distributed circumferentially at day 1 but began to organize into intercalated disk-like structures by day 6. The gap junction protein connexin43 followed a similar but delayed pattern relative to N-cadherin. From 2 to 8 weeks, there was progressive hypertrophy and the formation of mature intercalated disks. In some hearts, graft cells formed adherens and gap junctions with host cardiomyocytes, suggesting electromechanical coupling. More commonly, however, grafts were separated from the host myocardium by scar tissue. Gap and adherens junctions formed between neonatal and adult cardiomyocytes in coculture, as evidenced by dye transfer and localization of cadherin and connexin43 at intercellular junctions. CONCLUSIONS: Grafted fetal and neonatal cardiomyocytes form new, mature myocardium with the capacity to couple with injured host myocardium. Optimal repair, however, may require reducing the isolation of the graft by the intervening scar tissue.
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Diferenciación Celular/fisiología , Trasplante de Células , Tejido de Granulación/cirugía , Lesiones Cardíacas/cirugía , Miocardio/citología , Envejecimiento/fisiología , Animales , Animales Recién Nacidos/anatomía & histología , Cadherinas/metabolismo , Comunicación Celular/fisiología , División Celular/fisiología , Supervivencia Celular/fisiología , Frío , Conexina 43/metabolismo , Electrofisiología , Feto/citología , Masculino , Miocardio/metabolismo , Ratas , Ratas Endogámicas F344 , Valores de ReferenciaRESUMEN
OBJECTIVE: The cardiac sarcolemmal Na+/Ca(2+)-exchanger (NCX) plays an important role in the maintenance of the myocardial Ca2+ homeostasis which is altered in cardiac hypertrophy and failure. The aim of the present study was to investigate whether alpha-adrenergic stimulation known to induce cardiac hypertrophy might be involved in the regulation of the sarcolemmal NCX. METHODS: Adult rat ventricular cardiocytes (ARC) were isolated from male Sprague-Dawley rats. Phenylephrine, an alpha-adrenergic agonist, was used as hypertrophic agent. NCX expression was measured by competitive RT-PCR and Western blot analysis. RESULTS: alpha-Adrenergic stimulation of ARC with 10 microM phenylephrine for 24 h resulted in a significant increase of the NCX mRNA (2.5-fold) and the NCX protein level (1.8-fold). The changes on the expression level were blocked by the alpha 1-adrenoceptor antagonist prazosin. CONCLUSIONS: The data demonstrate that the NCX expression level is up-regulated by the activation of the alpha-adrenergic signal transduction pathway. The increased NCX mRNA level induced by alpha-adrenergic stimulation appeared to be translated into increased NCX protein level.
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Agonistas alfa-Adrenérgicos/farmacología , Miocardio/metabolismo , Fenilefrina/farmacología , Sarcolema/metabolismo , Intercambiador de Sodio-Calcio/efectos de los fármacos , Antagonistas Adrenérgicos alfa/farmacología , Animales , Western Blotting , Células Cultivadas , Masculino , Reacción en Cadena de la Polimerasa , Prazosina/farmacología , ARN Mensajero/análisis , Ratas , Ratas Sprague-Dawley , Intercambiador de Sodio-Calcio/genética , Estimulación QuímicaRESUMEN
OBJECTIVE: The aim of the present study was to investigate the functional activity and expression of the sarcolemmal Na+/Ca2+-exchanger in the failing human heart. METHODS: Left ventricular samples were taken from eleven patients with end-stage heart failure and six organ donors (normal controls). The Na+/Ca2+-exchanger activity was assessed by measuring Na+ gradient-induced 45Ca2+ transport into sarcolemmal vesicles of quantitatively collected crude membrane preparations. The abundance of the Na+/Ca2+-exchanger protein was determined by Western blot analysis using a specific antiserum and the results were normalized to myocyte specific beta-myosin heavy chain protein content. RESULTS: In membrane preparations of failing human hearts, both the Na+ gradient-induced 45Ca2+ transport activity and the level of immunoreactive Na+/Ca2+-exchanger protein were increased (P < 0.01) by 87% and 160% compared to controls, respectively. CONCLUSIONS: In human end-stage heart failure the increased sarcolemmal Na+/Ca2+-exchanger activity appears to be due to an elevated expression of this protein. An increase in the expression and activity of the Na+/Ca2+-exchanger in the failing human heart may be of important functional significance: while a resulting increase in Ca2+ extrusion across the sarcolemma may limit diastolic Ca2+ overload, a corresponding influx of Na+ may be associated with membrane depolarization and enhanced arrhythmogenesis if the Na+/Ca2+-exchanger operates primarily in the forward mode.
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Insuficiencia Cardíaca/metabolismo , Miocardio/metabolismo , ATPasa Intercambiadora de Sodio-Potasio/metabolismo , Adulto , Western Blotting , Calcio/metabolismo , Cardiomiopatía Dilatada/complicaciones , Cardiomiopatía Dilatada/metabolismo , Enfermedad Coronaria/complicaciones , Enfermedad Coronaria/metabolismo , Técnicas de Cultivo , Femenino , Insuficiencia Cardíaca/etiología , Humanos , Masculino , Persona de Mediana Edad , Sarcolema/metabolismo , Sodio/metabolismoRESUMEN
OBJECTIVE: c-FLIP is a natural homologue of caspase 8, and may antagonize activation of death pathways mediated by FADD. c-FLIP is highly expressed in the heart, and a recent report suggests that c-FLIP may protect against certain types of myocyte death. The present study was designed to define the expression patterns of c-FLIP in the heart. METHODS: The expression pattern of c-FLIP in end-stage human hearts, and rat cardiomyocyte grafting models was analyzed by in situ hybridization, immunohistochemistry and TUNEL assay. In addition, to determine whether Fas-dependent pathway is active in cardiomyocytes in vitro, we examined whether activated monocytes can kill neonatal cardiomyocytes in a co-culture system. RESULTS: c-FLIP mRNA and protein were abundantly expressed in normal cardiomyocytes from failing human heart. In animal models, c-FLIP protein was absent in TUNEL-positive grafted cardiomyocytes. Double staining demonstrated that c-FLIP-positive cells rarely had fragmented DNA, while TUNEL-positive cells rarely contained c-FLIP. Finally, activated monocytes induced death of neonatal rat cardiomyocytes via the Fas/FasL system. CONCLUSIONS: Loss of c-FLIP expression correlates with cardiomyocyte cell death. We hypothesize that diminished c-FLIP expression may predispose cardiomyocytes to apoptotic death.