RESUMEN
Valvular heart disease is a common comorbidity in patients with impaired renal function, especially in those with end-stage renal disease undergoing dialysis. Sclerosis and calcification of the heart valves and the valve ring are particularly relevant in the etiology of the diseases. These typically occur at the aortic and mitral valves and can lead to both insufficiency and stenosis of the affected valve. In the current guidelines of the European Society for Cardiology published in 2017, surgical treatment remains the standard of care for most forms of severe valvular heart disease; however, the presence of chronic kidney disease impairs clinical outcomes and is associated with higher mortality rates when compared to patients with preserved renal function. Catheter-based treatment options have emerged as an effective and safe alternative for patients >75 years and/or with increased surgical risk. Consequently, in patients with appropriate anatomy and elevated risk, interventional treatment options should also be discussed in the heart team.
Asunto(s)
Válvula Aórtica/cirugía , Enfermedades de las Válvulas Cardíacas/cirugía , Implantación de Prótesis de Válvulas Cardíacas , Insuficiencia Renal Crónica/complicaciones , Reemplazo de la Válvula Aórtica Transcatéter , Válvula Aórtica/fisiopatología , Cardiología , Enfermedades de las Válvulas Cardíacas/etiología , Humanos , Válvula Mitral , Insuficiencia de la Válvula Mitral/fisiopatología , Resultado del Tratamiento , Insuficiencia de la Válvula Tricúspide , Disfunción Ventricular Izquierda/fisiopatologíaRESUMEN
There is a close physiological relationship between the kidneys and the heart. Cardiovascular diseases are the most prevalent cause of death in patients with chronic kidney disease (CKD), whereas CKD may directly accelerate the progression of cardiovascular diseases and is considered to be a cardiovascular risk factor. In patients with mild CKD, i.e. an estimated glomerular filtration rate (eGFR) >60â¯ml/min/1.73â¯m2, treatment of coronary artery disease and chronic heart failure is not essentially different from patients with preserved renal function; however, as most pivotal trials have systematically excluded patients with advanced renal failure, many treatment recommendations in this patient group are based on observational studies, post hoc subgroup analyses and meta-analyses or pathophysiological considerations, which are not supported by controlled studies. Therefore, prospective randomized studies on the management of heart failure and coronary artery disease are needed, which should specifically focus on the growing number of patients with advanced renal functional impairment.
Asunto(s)
Enfermedades Cardiovasculares , Fallo Renal Crónico , Revascularización Miocárdica , Insuficiencia Renal Crónica , Insuficiencia Renal , Enfermedades Cardiovasculares/complicaciones , Enfermedades Cardiovasculares/cirugía , Tasa de Filtración Glomerular , Humanos , Estudios Prospectivos , Insuficiencia Renal Crónica/complicacionesRESUMEN
A standardized medication plan (MP) was recently enacted into German law (§ 31a SGB V). The purpose of our study was to assess if patients with chronic diseases requiring polymedication understand the standardized MP and can transfer the given information into practice. 100 patients who took at least five medicines regularly were prospectively included in a cross-sectional study: 50 patients with the primary diagnosis chronic heart failure (CHF), and 50 with diabetes mellitus type 2 (DMT2). We performed a structured test-scenario studying the handling of a provided MP then evaluated the execution of the information on the MP by filling pill boxes and requested patients' opinion. An established weighted scoring system, the "Evaluation Tool to test the handling of the Medication Plan" (ET-MP) was applied to quantitate the ability of the patients to handle the MP. In addition, signs of depression, cognitive function and self-care behavior in chronic heart failure were characterized using the PHQ-9, Mini-Cog, and G9-EHFScB-9 questionnaires, respectively. The understanding of the MP was poor and irrespective of the underlying primary diagnosis. Only 32% of all patients were able to handle the MP without difficulties (ET-MP score >90%), the median ET-MP score was 83 [(IQR) 50-98]. Comprehension of the MP was better in patients aged <70 years compared to ≥70 years (p<0.01). Patients ≥10 years of education achieved higher ET-MP results than patients with <10 years of education (p<0.01). Patients with signs of cognitive impairment exhibited significantly lower ET-MP scores than patients without cognitive impairment (p<0.001). There were no significant correlations of the ET-MP score with number of daily medications, living situation, sex, the Charlson Comorbidity Index, the PHQ-9 score, and use of a dosing aid or possession of a medication list.
Asunto(s)
Cognición , Comprensión , Diabetes Mellitus Tipo 2/tratamiento farmacológico , Insuficiencia Cardíaca/tratamiento farmacológico , Factores de Edad , Anciano , Enfermedad Crónica , Disfunción Cognitiva/epidemiología , Estudios Transversales , Depresión/epidemiología , Diabetes Mellitus Tipo 2/psicología , Escolaridad , Femenino , Alemania , Insuficiencia Cardíaca/psicología , Humanos , Masculino , Persona de Mediana Edad , Polifarmacia , Estudios Prospectivos , Autocuidado/estadística & datos numéricos , Encuestas y CuestionariosRESUMEN
BACKGROUND: Disparity in health status and healthcare outcomes is widespread and well known. This holds true for Indigenous peoples in many settings including Australia and Hawaii. While multi-factorial, there is increasing evidence of health practitioner contribution to this disparity. This research explored senior medical students' clinical decision-making processes. METHODS: A qualitative study was conducted in 2014 with 30 final year medical students from The University of Melbourne, Australia, and The John Burns Medical School, Hawaii, USA. Each student responded to questions about a paper-based case, first in writing and elaborated further in an interview. Half the students were given a case of a patient whose ethnicity was not declared; the other half considered the patient who was Native Hawaiian or Australian Aboriginal. A systematic thematic analysis of the interview transcripts was conducted. RESULTS: The study detected subtle biases in students' ways of talking about the Indigenous person and their anticipation of interacting with her as a patient. Four main themes emerged from the interview transcripts: the patient as a person; constructions of the person as patient; patient-student/doctor interactions; and the value of various education settings. There was a strong commitment to the patient's agenda and to the element of trust in the doctor-patient interaction. CONCLUSION: These findings will help to advance medical curricula so that institutions graduate physicians who are increasingly able to contribute to equitable outcomes for all patients in their care. The study also draws attention to subtle biases based on ethnicity that may be currently at play in physicians' practices.
Asunto(s)
Toma de Decisiones Clínicas , Educación Médica/ética , Etnicidad , Servicios de Salud del Indígena/ética , Disparidades en Atención de Salud , Prejuicio/etnología , Estudiantes de Medicina/psicología , Adulto , Educación Médica/métodos , Femenino , Disparidades en el Estado de Salud , Humanos , Masculino , Nativos de Hawái y Otras Islas del Pacífico/etnología , Investigación Cualitativa , Adulto JovenRESUMEN
Chronic heart failure is one of the most common chronic diseases worldwide with increasing prevalence and incidence. Due to the high morbidity and mortality a standardized and evidence-based therapy is essential. The present article gives an overview of the innovations from 2014 based on the current guidelines of the European Society of Cardiology. First, improvements of established medication regimens regarding beta blockers, mineralocorticoid receptor antagonists and treatment options for heart rate reduction and disease management programs will be explained. Second, new pharmacological developments, such as the new substance class of angiotensin receptor blockers and neprilysin inhibitors (ARNI), will be presented. Finally, new insights into common comorbidities of chronic heart failure patients, such as atrial fibrillation and hyperkalemia will be discussed.
Asunto(s)
Antagonistas Adrenérgicos beta/administración & dosificación , Antagonistas de Receptores de Angiotensina/administración & dosificación , Cardiología/normas , Cardiopatías/tratamiento farmacológico , Antagonistas de Receptores de Mineralocorticoides/administración & dosificación , Guías de Práctica Clínica como Asunto , Cardiotónicos/administración & dosificación , Enfermedad Crónica , Europa (Continente) , Medicina Basada en la Evidencia , Alemania , Cardiopatías/diagnóstico , Humanos , Neprilisina/antagonistas & inhibidores , Resultado del TratamientoRESUMEN
Hypertension is the most common chronic cardiovascular disease with increasing prevalence all over the world. Despite the availability of many effective antihypertensive drugs, blood pressure control to target values remains low. In the pathophysiology of therapy resistant hypertension, increased activity of the sympathetic nervous system with an imbalance between sympathetic and parasympathetic activity has been identified as a main contributor to the development and maintenance of hypertension. Catheter-based denervation of the renal sympathetic nerves has been described as reducing blood pressure and decreasing sympathetic activity in patients with resistant hypertension. Supplementary beneficial effects on common cardiovascular comorbidities, such as diabetes type 2, have been reported. The present review aims to give an overview about percutaneous renal denervation for treatment of hypertension and potential new therapeutic options to improve glycemic control.
Asunto(s)
Glucemia/metabolismo , Presión Sanguínea , Complicaciones de la Diabetes/fisiopatología , Hipertensión/fisiopatología , Hipertensión/cirugía , Riñón/inervación , Simpatectomía/métodos , Complicaciones de la Diabetes/cirugía , Humanos , Hipertensión/etiología , Riñón/cirugía , Resultado del TratamientoRESUMEN
The assessment of valvular pathologies in multiple valvular heart disease by echocardiography remains challenging. Data on echocardiographic assessment-especially in patients with combined aortic and mitral regurgitation-are rare in the literature. The proposed integrative approach using semi-quantitative parameters to grade the severity of regurgitation often yields inconsistent findings and results in misinterpretation. Therefore, this proposal aims to focus on a practical systematic echocardiographic analysis to understand the pathophysiology and hemodynamics in patients with combined aortic and mitral regurgitation. The quantitative approach of grading the regurgitant severity of each compound might be helpful in elucidating the scenario in combined aortic and mitral regurgitation. To this end, both the individual regurgitant fraction of each valve and the total regurgitant fraction of both valves must be determined. This work also outlines the methodological issues and limitations of the quantitative approach by echocardiography. Finally, we present a proposal that enables verifiable assessment of regurgitant fractions. The overall interpretation of echocardiographic results includes the symptomatology of patients with combined aortic and mitral regurgitation and the individual treatment options with respect to their individual risk. In summary, a reproducible, verifiable, and transparent in-depth echocardiographic investigation might ensure consistent hemodynamic plausibility of the quantitative results in patients with combined aortic and mitral regurgitation.
Asunto(s)
Insuficiencia de la Válvula Aórtica , Insuficiencia de la Válvula Mitral , Humanos , Insuficiencia de la Válvula Mitral/diagnóstico , Insuficiencia de la Válvula Mitral/etiología , Insuficiencia de la Válvula Aórtica/diagnóstico , Ecocardiografía/métodos , HemodinámicaRESUMEN
Currently, the term "heart failure with preserved left ventricular ejection fraction (HFpEF)" is based on echocardiographic parameters and clinical symptoms combined with elevated or normal levels of natriuretic peptides. Thus, "HFpEF" as a diagnosis subsumes multiple pathophysiological entities making a uniform management plan for "HFpEF" impossible. Therefore, a more specific characterization of the underlying cardiac pathologies in patients with preserved ejection fraction and symptoms of heart failure is mandatory. The present proposal seeks to offer practical support by a standardized echocardiographic workflow to characterize specific diagnostic entities associated with "HFpEF". It focuses on morphological and functional cardiac phenotypes characterized by echocardiography in patients with normal or preserved left ventricular ejection fraction (LVEF). The proposal discusses methodological issues to clarify why and when echocardiography is helpful to improve the diagnosis. Thus, the proposal addresses a systematic echocardiographic approach using a feasible algorithm with weighting criteria for interpretation of echocardiographic parameters related to patients with preserved ejection fraction and symptoms of heart failure. The authors consciously do not use the diagnosis "HFpEF" to avoid misunderstandings. Central illustration: Scheme illustrating the characteristic echocardiographic phenotypes and their combinations in patients with "HFpEF" symptoms with respect to the respective cardiac pathology and pathophysiology as well as the underlying typical disease.
Asunto(s)
Insuficiencia Cardíaca , Función Ventricular Izquierda , Humanos , Volumen Sistólico/fisiología , Función Ventricular Izquierda/fisiología , Insuficiencia Cardíaca/diagnóstico por imagen , Insuficiencia Cardíaca/complicaciones , Ecocardiografía/métodosRESUMEN
PURPOSE: Interocular brightness differences such as those caused by asymmetrical cataract have been found to have a minimal effect on interocular brightness matches. In the present study, the measured binocular visual response to interocular differences in retinal illuminance was measured over time. METHODS: Interocular differences in retinal illuminance of magnitudes 0.3, 0.6, and 0.9 log units were induced using neutral density (ND) filters under two conditions: (1) naturally mobile pupils and (2) with fixed artificial pupils (3 mm). Interocular brightness differences were quantified by measuring interocular brightness matches using the simultaneous interocular brightness sense test every 15 minutes over a 2-hour period in eight visually normal subjects. RESULTS: Initial interocular brightness matches were as predicted by the induced interocular differences in retinal illuminance (P > 0.05). A significant reduction in the interocular difference in brightness was observed over time (P < 0.01). These reductions in the interocular difference in brightness over time followed a logarithmic progression reaching asymptotic values equal to the reciprocal of the square root of the interocular retinal illuminance ratio. This value is equal to the midpoint of the induced interocular difference in retinal illuminance at time 0 and that found without the introduction of the ND filters. Binocular visual adaptation to interocular brightness differences occurred with both mobile and fixed pupils. CONCLUSIONS: Visual adaptation occurs in response to interocular brightness differences induced by asymmetrical ND filters. The level of visual adaptation can be predicted by Fechner's Paradox and is independent of interocular differences in pupil diameter.
Asunto(s)
Adaptación Ocular/fisiología , Luz , Retina/efectos de la radiación , Visión Binocular/fisiología , Adulto , Humanos , Agudeza Visual/fisiología , Percepción Visual/fisiologíaRESUMEN
The activities of diamine and polyamine oxidases, two enzymes of polyamine catabolism, were studied in hyperplastic growth of rat small intestine induced by phytohaemagglutinin. This growth, evaluated by the elongation of Lieberkühn's crypts, was more extensive in the proximal than in the distal parts of the gut. The activity of diamine oxidase was significantly reduced in the proximal (70%), medial (45%) and the distal (25%) parts. The activity of polyamine oxidase was doubled. The concentrations of putrescine, cadaverine and spermidine were significantly elevated in the three intestinal parts studied, whereas those of histamine and spermine were unchanged. It appears that changes in the activities of diamine and polyamine oxidases may contribute to the increased putrescine content, which is necessary to maintain active polyamine turnover for sustaining growth of the gut.
Asunto(s)
Amina Oxidasa (conteniendo Cobre)/metabolismo , Intestino Delgado/citología , Oxidorreductasas actuantes sobre Donantes de Grupo CH-NH/metabolismo , Animales , División Celular/efectos de los fármacos , Diaminas/metabolismo , Hipertrofia/enzimología , Intestino Delgado/enzimología , Fitohemaglutininas/farmacología , Poliaminas/metabolismo , Ratas , Poliamino OxidasaRESUMEN
ACCESSIBLE SUMMARY: Studies have indicated that individuals who are homeless access hospital emergency departments more frequently and may have different needs than individuals who are housed. Successful interventions have been developed and tested to reduce discharge to homelessness for psychiatric inpatients but have not been similarly tested for discharge from emergency departments. This study was developed to provide baseline data on this issue to inform future emergency department interventions. Findings from the current study suggest that discharge from emergency departments to homelessness happens frequently in London, Canada. Participants are unlikely to spontaneously disclose their housing/homelessness issue when first entering the emergency department, which may result in services that do not adequately meet their complex needs. Screening for housing issues is necessary within emergency departments and psychiatric crisis teams as housing issues may be a reason for accessing care or contribute to the presenting condition. Nurses are in an ideal position to evaluate housing needs among emergency department patients. Services outside of the emergency department are also needed to address housing issues, particularly outside of regular office hours. ABSTRACT: Individuals who have mental health issues and are homeless or in housing crisis have been found to access emergency departments more frequently than individuals with stable housing. While emergency departments primarily focus on medical issues, homeless individuals may require psychosocial support as well. This study examined issues around housing crises and emergency department use for individuals with mental illness in Canada. Collecting baseline data about these issues is important to inform subsequent interventions. Administrative data from a hospital emergency department and psychiatric crisis service were collected, and five individuals accessing the emergency department for psychiatric reasons were interviewed. Results indicated that individuals with an identified housing crisis accessed the emergency department 930 times in 6 months. None of the interview participants identified housing as the primary reason for accessing the emergency department, but all noted that housing was a contributing stressor. Future research is needed to examine ways in which discharge to homelessness from emergency departments can be avoided and identify alternative services to address housing concerns, particularly for individuals with mental illness. Crisis service and emergency department staff, especially nurses, can play an important role in screening for housing issues and connecting individuals to outside services.
Asunto(s)
Servicio de Urgencia en Hospital/estadística & datos numéricos , Vivienda/estadística & datos numéricos , Personas con Mala Vivienda/estadística & datos numéricos , Alta del Paciente/estadística & datos numéricos , Adulto , Femenino , Humanos , Masculino , OntarioRESUMEN
We describe the pro-inflammatory and cytotoxic effects of nitric oxide in vivo in human skin. Nitrite and ascorbic acid were mixed on the skin of 12 normal volunteers, three times daily, to release nitric oxide. Exposure to nitric oxide was varied by randomizing the concentration of nitrite and duration of application. Nitric oxide treated skin showed significant increases in cells expressing CD3, CD4, CD8, CD68, neutrophil elastase, ICAM-1, VCAM-1, nitrosotyrosine, p53, and apoptotic cells compared with skin treated with ascorbic acid alone. There was no significant increase in mast cells. Following application of nitric oxide there were significantly fewer CD1a positive Langerhans cells in the epidermis. These appeared to lose dendritic morphology and migrate from the epidermis. There was no significant difference in staining for Ki-67, a marker related to proliferating cell nuclear antigen, between active and control skin but staining was greater after exposure to higher dose nitric oxide than the low dose. Apoptosis, cytotoxicity, and p53 staining were relatively greater after 48 h exposure than after 24 h. These results suggest that nitric oxide is pro-inflammatory and is toxic to DNA, leading to the accumulation of p53 and subsequent apoptosis. High-dose nitric oxide paradoxically led to a smaller increase in macrophages and T cells than low dose suggesting an immunosuppressive effect of higher levels.
Asunto(s)
Apoptosis/efectos de los fármacos , Inflamación/inducido químicamente , Óxido Nítrico/farmacología , Piel/efectos de los fármacos , División Celular/efectos de los fármacos , Relación Dosis-Respuesta a Droga , Humanos , Inmunohistoquímica , Molécula 1 de Adhesión Intercelular/biosíntesis , Queratinocitos/efectos de los fármacos , Piel/patología , Proteína p53 Supresora de Tumor/análisis , Molécula 1 de Adhesión Celular Vascular/biosíntesisRESUMEN
Experiments were designed to investigate whether orally consumed tomato lectin could resist the digestive process and function as a lectin within the alimentary canal. Rats fed on a tomato lectin-rich diet passed faeces containing serologically detectable tomato lectin, and the lectin could be shown by immunoperoxidase staining bound to intestinal villi. Moreover, radioactivity was mainly recovered from the alimentary canal 3h after 125I-labelled tomato lectin administration with only traces in the circulation or internal organs. Radioactivity absorbed into the human circulation after consumption of 125I-labelled tomato lectin was also less than that expected for a digestable protein.
Asunto(s)
Sistema Digestivo/metabolismo , Mucosa Intestinal/metabolismo , Lectinas/metabolismo , Administración Oral , Animales , Sitios de Unión , Dieta , Humanos , Técnicas para Inmunoenzimas , Absorción Intestinal , Lectinas de Plantas , Ratas , Distribución Tisular , VerdurasRESUMEN
The expression of CYP1B1 has been identified in breast cancer using the reverse transcriptase-polymerase chain reaction and immunoblotting. CYP1B1 mRNA was expressed in the majority of breast tumours and immunoblotting of breast tumours identified a single protein band of molecular weight 60 kDa corresponding to the predicted molecular weight of human CYP1B1. This is the first study to identify CYP1B1 expression in a tumour where it may represent a previously unknown pathway for the metabolism of oestradiol and chemotherapeutic drugs.
Asunto(s)
Hidrocarburo de Aril Hidroxilasas , Neoplasias de la Mama/enzimología , Sistema Enzimático del Citocromo P-450/biosíntesis , Adulto , Anciano , Anciano de 80 o más Años , Secuencia de Bases , Neoplasias de la Mama/patología , Citocromo P-450 CYP1B1 , Sistema Enzimático del Citocromo P-450/genética , Cartilla de ADN , Femenino , Humanos , Immunoblotting , Persona de Mediana Edad , Datos de Secuencia Molecular , Reacción en Cadena de la Polimerasa , ARN Mensajero/metabolismo , Transcripción GenéticaRESUMEN
The increments in plasma zinc concentrations after an oral dose of elemental zinc (50 mg) as the sulphate were used to assess the intestinal absorption of the metal in 11 patients with dermatitis herpetiformis (DH) before starting a gluten-free diet, 12 patients with newly diagnosed celiac disease (CD), 10 patients known to have CD, and 15 healthy volunteers. The areas under the plasma zinc increment curve plotted against time were determined for 3 (AUC3) and 6 (AUC6) h. The AUC3 in healthy volunteers was 401 +/- 48 mumol 1(-1) 3 h (mean +/- SD); it was reduced in newly diagnosed CD 187 +/- 76 mumol 1(-1) 3 h (p less than 0.001), and in dermatitis herpetiformis 206 +/- 87 mumol 1(-1) 3 h (p less than 0.01); but it was normal in the known CD 396 +/- 204 mumol 1(-1) 3 h, the wide variation reflecting the variable compliance with a previously instituted gluten-free diet. The AUC6 was similarly affected, healthy volunteers 700 +/- 111 mumol 1(-1) 6 h, new CD 380 +/- 169 mumol 1(-1) 6 h (p less than 0.01); dermatitis herpetiformis 471 +/- 107 mumol 1(-1) 6 h (p less than 0.01); known CD 725 +/- 380 mumol 1(-1) 6 h. The AUC3 was more consistently abnormal than conventional tests of small intestinal function. In a prospective study the AUC3 and AUC6 improved and reflected compliance with a gluten-free diet.
Asunto(s)
Enfermedad Celíaca/sangre , Dermatitis Herpetiforme/sangre , Zinc/sangre , Adolescente , Adulto , Anciano , Enfermedad Celíaca/dietoterapia , Enfermedad Celíaca/fisiopatología , Dermatitis Herpetiforme/dietoterapia , Dermatitis Herpetiforme/fisiopatología , Femenino , Glútenes/administración & dosificación , Humanos , Absorción Intestinal , Intestino Delgado/patología , Intestino Delgado/fisiopatología , Masculino , Persona de Mediana EdadRESUMEN
We developed a method for histochemical demonstration of a wide range of enzymes in freeze-substituted glycol methacrylate-embedded tissue. Tissue specimens were freeze-substituted in acetone and then embedded at low temperature in glycol methacrylate resin. All enzymes studied (oxidoreductases, hydrolases) were readily demonstrated. The enzymes displayed high activity and were accurately localized without diffusion when tissue sections were incubated in aqueous media, addition of colloid stabilizers to the incubating media not being required. Freeze-substitution combined with low-temperature glycol methacrylate embedding permits the demonstration of a wide range of enzymes with accurate enzyme localization, maintenance of enzyme activity, and excellent tissue morphology.
Asunto(s)
Acrilatos , Enzimas/análisis , Liofilización , Histocitoquímica/métodos , Metacrilatos , Animales , Femenino , Hidrolasas/análisis , Yeyuno/enzimología , Riñón/enzimología , Hígado/enzimología , Ratones , Oxidorreductasas/análisis , Bazo/enzimologíaRESUMEN
We have developed a new fluorescence method for the histochemical localization of alkaline phosphatase activity. Calcium phosphate deposited at the sites of alkaline phosphatase activity in a Gomori-type reaction are identified by calcium binding fluorochromes. The calcium binding fluorochromes calcein, calcein blue, and xylenol orange were investigated, with each fluorochrome being included in the alkaline phosphatase incubating medium and used in a single-step procedure. Alkaline phosphatase activity was studied in freeze-substituted, resin-embedded human liver and jejunal biopsies, and each fluorochrome produced intense fluorescence of different colors at sites of alkaline phosphatase activity. Calcein, calcein blue, and xylenol orange produced green, blue, and red fluorescence, respectively. Sites of enzyme activity were accurately localized without evidence of diffusion, and there was an absence of non-enzyme-catalyzed binding of any of the fluorochromes to tissue. This fluorescence method, which is particularly suited to investigating the localization and distribution of the activity of different enzymes in the same section, was used to investigate the distribution and co-localization of alkaline phosphatase and aminopeptidase M in human liver and jejunum.
Asunto(s)
Fosfatasa Alcalina/análisis , Fluorescencia , Histocitoquímica/métodos , Aminopeptidasas/análisis , Biopsia , Antígenos CD13 , Colorantes Fluorescentes , Humanos , Yeyuno/enzimología , Yeyuno/patología , Hígado/enzimología , Hígado/patologíaRESUMEN
We developed a new method for the histochemical demonstration of peroxidase. This method, which has a novel reaction mechanism, is based on the oxidation of phenol by peroxidase and coupling of this reaction to the reduction of a tetrazolium salt, with the deposition of an insoluble formazan at sites of enzyme activity. This new method was compared with an established diaminobenzidine (DAB) technique for peroxidase histochemistry and immunohistochemistry. Although both methods identified peroxidase activity in myeloid cells of bone marrow biopsy specimens, there was no interference from red cell pseudoperoxidase activity with the phenol-tetrazolium method, in contrast to the diaminobenzidine method. The detection of cytokeratin using an indirect immunoperoxidase technique was compared with both methods for demonstrating peroxidase activity. The phenol-tetrazolium method gave results similar to that obtained with DAB and appeared to be at least as sensitive as DAB in detecting low amounts of antigen. In addition, the production of a formazan as the final reaction product means that the phenol-tetrazolium method is ideally suited for quantitative peroxidase histochemistry. Therefore, the phenol-tetrazolium method represents a useful alternative method to DAB and for certain applications offers significant advantages over DAB.
Asunto(s)
Técnicas para Inmunoenzimas , Sales de Tetrazolio , Médula Ósea/metabolismo , Células de la Médula Ósea , Colon/citología , Colon/metabolismo , Células Epiteliales , Epitelio/metabolismo , Humanos , Queratinas/metabolismo , Fenoles , p-DimetilaminoazobencenoRESUMEN
We describe a method for enzyme histochemical demonstration of NADH dehydrogenase in cold (4 degrees C)-processed resin-embedded tissue. The effects on NADH dehydrogenase activity of processing tissue through a variety of dehydrating agents and embedding in three different acrylic resins were evaluated. The optimal procedure to maintain NADH dehydrogenase activity used a short (3-hr) fixation in 1% paraformaldehyde solution, followed by dehydration in acetone and embedding in glycol methacrylate resin. Embedding of tissue in resin combined preservation and accurate localization of NADH dehydrogenase activity with good tissue morphology. Blocks of the resin-embedded tissue could be stored at room temperature for at least 6 months without loss of NADH dehydrogenase activity.
Asunto(s)
Reductasas del Citocromo/metabolismo , Histocitoquímica/métodos , NADH Deshidrogenasa/metabolismo , Animales , Fijadores , Ratones , Resinas de Plantas , Conservación de TejidoRESUMEN
We have developed a method for histochemical demonstration of a wide range of enzymes in freeze-dried, resin-embedded tissue. Freeze-dried tissue specimens were embedded without fixation at low temperature (4 degrees C or -20 degrees C) in glycol methacrylate resin or LR Gold resin. Enzyme activity was optimally preserved by embedding the freeze-dried tissue in glycol methacrylate resin. All enzymes studied (oxidoreductases, esterases, peptidases, and phosphatases), except for glucose-6-phosphatase, were readily demonstrated. The enzymes displayed high activity and were accurately localized without diffusion when tissue sections were incubated in aqueous media, addition of colloid stabilizers to the incubating media not being required. Freeze-drying combined with low-temperature resin embedding permits the demonstration of a wide range of enzymes with accurate enzyme localization, high enzyme activity, and excellent tissue morphology.