RESUMO
This study presents a fractional calculus model as a generalized kinetic model for estimating the maximum methane yield and degradation kinetics in biomethane potential (BMP) assays, a key analytical method in anaerobic digestion research and application. The fractional model outperformed common first-order kinetic models by yielding superior data fitting and properly managing substrate heterogeneity. The fractional model showed robust performance in mono-digestion, co-digestion and pre-treatment BMP assays with or without presence of large tailing or sigmoidal patterns in the BMP curve. The main advantage of the fractional model over other models is its ability to capture the complexities of the methane production process without losing model accuracy. Assessment of the mathematical model revealed that for fractional orders greater than 0.8 the Mittag-Leffler sequence could be transformed into a more computationally efficient exponential function.
Assuntos
Metano , Modelos Teóricos , Anaerobiose , Reatores BiológicosRESUMO
Spain has become one of the most active countries in donation after controlled cardiac death, using normothermic abdominal perfusion with ECMO in more than 50% of all donors - a situation contributed to by the creation of mobile teams to support hospitals lacking this technology. The donation process must be respectful of the wishes and values of the patients and their relatives, especially if there is pre mortem manipulation, and the absence of cerebral perfusion should be guaranteed. The liver is the most benefited organ by reducing biliary complications as well as the loss of grafts. In renal transplantation, the technique could contribute to reduce the incidence of delayed graft function. In addition, the procedure is compatible with surgical rapid recovery in hypothermia when there is also lung donation. The future lies in the consolidation of cardiac donation by extending normothermic perfusion to the thoracic cavity.
Assuntos
Oxigenação por Membrana Extracorpórea , Morte , Humanos , Preservação de Órgãos , Perfusão , EspanhaRESUMO
Spain has become one of the most active countries in donation after controlled cardiac death, using normothermic abdominal perfusion with ECMO in more than 50% of all donors - a situation contributed to by the creation of mobile teams to support hospitals lacking this technology. The donation process must be respectful of the wishes and values of the patients and their relatives, especially if there is pre mortem manipulation, and the absence of cerebral perfusion should be guaranteed. The liver is the most benefited organ by reducing biliary complications as well as the loss of grafts. In renal transplantation, the technique could contribute to reduce the incidence of delayed graft function. In addition, the procedure is compatible with surgical rapid recovery in hypothermia when there is also lung donation. The future lies in the consolidation of cardiac donation by extending normothermic perfusion to the thoracic cavity.
RESUMO
Polycystic kidney disease is a complex clinical entity which comprises a group of genetic diseases that leads to renal cyst development. We evaluated the most suitable housekeeping genes for microRNA expression by RT-qPCR analyses of kidney tissues in Pkd1-deficient mouse models from a panel of five candidates genes (miR-20a, miR-25, miR-26a, miR-191 and U6) and 3 target genes (miR-17, miR-21 and let-7a) using samples from kidneys of cystic mice (Pkd1flox/flox:Nestincre, CY), non-cystic controls (Pkd1flox/flox, NC), Pkd1-haploinsufficient (Pkd1+/-, HT), wild-type controls (Pkd1+/+, WT), severely cystic mice (Pkd1V/V, SC), wild-type controls (CO). The stability of the candidate genes was investigated using NormFinder, GeNorm, BestKeeper, DataAssist, and RefFinder software packages and the comparative ΔCt method. The analyses identified miR-26a as the most stable housekeeping gene for all kidney samples, miR-20a for CY and NC, miR-20a and miR-26a for HT and WT, and miR-25 and miR-26a for SC and CO. Expression of miR-21 was upregulated in SC compared to CO and trends of miR-21 upregulation and let-7a downregulation in CY and HT compared to its control kidneys, when normalized by different combinations of miR-20a, miR-25 and miR-26a. Our findings established miR-20a, miR-25, and miR-26a as the best housekeeping genes for miRNA expression analyses by RT-qPCR in kidney tissues of Pkd1-deficient mouse models.
Assuntos
Perfilação da Expressão Gênica , Genes Essenciais/genética , Rim/metabolismo , MicroRNAs/genética , Proteína Quinase C/deficiência , Animais , Haploinsuficiência , Camundongos , Proteína Quinase C/genéticaRESUMO
The use of extracorporeal membrane oxygenation systems has increased significantly in recent years; given this reality, the Spanish Society of Critical Intensive Care Medicine and Coronary Units (SEMICYUC) has decided to draw up a series of recommendations that serve as a framework for the use of this technique in intensive care units. The three most frequent areas of extracorporeal membrane oxygenation systems use in our setting are: as a cardiocirculatory support, as a respiratory support and for the maintenance of the abdominal organs in donors. The SEMICYUC appointed a series of experts belonging to the three working groups involved (Cardiological Intensive Care and CPR, Acute Respiratory Failure and Transplant work group) that, after reviewing the existing literature until March 2018, developed a series of recommendations. These recommendations were posted on the SEMICYUC website to receive suggestions from the intensivists and finally approved by the Scientific Committee of the Society. The recommendations, based on current knowledge, are about which patients may be candidates for the technique, when to start it and the necessary infrastructure conditions of the hospital centers or, the conditions for transfer to centers with experience. Although from a physiopathological point of view, there are clear arguments for the use of extracorporeal membrane oxygenation systems, the current scientific evidence is weak, so studies are needed that define more precisely which patients benefit most from the technique and when they should start.
Assuntos
Cuidados Críticos/métodos , Cuidados Críticos/normas , Oxigenação por Membrana Extracorpórea , Humanos , Unidades de Terapia IntensivaRESUMO
INTRODUCTION: The association between headache clinical parameters and other health-related and neuro-physiological outcomes is controversial. AIM: To investigate the association between headache frequency, duration and intensity with cranio-cervical pressure sensitivity considering the interaction of health-related and physical outcomes. PATIENTS AND METHODS: Seventy-two individuals with tension type headache were included. A 1-month diary was used to assess headache frequency, duration and intensity. Pressure pain thresholds (PPT) and peri-cranial tenderness to palpation, health-related quality of life (Short Form-36), disability, depression, and cervical range of motion were the outcomes. All outcomes were introduced into hierarchic logistic regression models to assess potential associations. RESULTS: Several associations between headache frequency and duration, but not intensity, with the remaining variables were found. Regression analysis showed that PPT over the temporalis muscle, bodily pain, age and physical role explained the 22.3% of the headache frequency, whereas general health, PPT over the upper trapezius and headache frequency explained 20% of headache duration (p < 0.001). CONCLUSIONS: This study found that headache frequency and duration, but not headache intensity, were associated with neurophysiological outcomes, e.g., cranio-cervical pressure sensitivity, and bodily pain in tension type headache. Other variables including age, physical role and general health were also associated with headache frequency and duration.
TITLE: Asociacion de la frecuencia y duracion, pero no la intensidad, de la cefalea con la hipersensibilidad mecanica y la salud en pacientes con cefalea de tension.Introduccion. La asociacion entre las variables clinicas de la cefalea y otras variables neurofisiologicas o de salud es controvertida. Objetivo. Determinar la asociacion de la frecuencia, duracion e intensidad del dolor con la sensibilidad mecanica craneocervical, considerando el efecto de otras variables de salud y fisicas. Pacientes y metodos. Se incluyeron 72 pacientes con cefalea de tension. Se mantuvo un diario mensual para determinar la frecuencia, duracion e intensidad del dolor. Se calcularon los umbrales de dolor a la presion (UDP) y la sensibilidad a la palpacion sobre la region craneocervical, calidad de vida (Short Form-36), discapacidad, depresion y movilidad cervical. Se introdujeron todas las variables en modelos de regresion logistica jerarquica para determinar las interacciones. Resultados. Se encontraron correlaciones entre la frecuencia y duracion de la cefalea, pero no la intensidad, con el resto de variables. El analisis de regresion mostro que la combinacion del UDP sobre el temporal, dolor corporal, edad y rol fisico explicaba el 22,3% de la varianza de la frecuencia, mientras que la combinacion de salud general, UDP sobre el trapecio superior y frecuencia del dolor explicaba el 20% de la varianza de la duracion (p < 0,001). Conclusiones. Este estudio ha encontrado que la frecuencia y la duracion de la cefalea, pero no la intensidad, se encuentran asociadas con variables neurofisiologicas, como el UDP sobre el cuello/cabeza o la percepcion de dolor generalizado en la cefalea tensional. Otras variables, como la edad, el rol fisico y la salud general tambien mostraron una asociacion con la frecuencia y la duracion de la cefalea.
Assuntos
Cefaleia do Tipo Tensional/diagnóstico , Cefaleia do Tipo Tensional/fisiopatologia , Fenômenos Biomecânicos , Feminino , Humanos , Pessoa de Meia-Idade , Limiar da Dor , Pressão , Fatores de TempoRESUMO
OBJECTIVE: To examine the associations between function, quality of life, personality, cognitive and psychological outcomes with fatigue in patients with MS. METHODS: One hundred and eight patients (54% women) with definite MS participated. MS-related fatigue was assessed with the Fatigue Impact Scale (FIS). Demographic and clinical data (weight, height, medication and history of pain), specific disease outcomes (Functional Assessment of Multiple Sclerosis/FAMS), general disease outcomes (Beck Depression Inventory/BDI-II, and Short-Form Health Survey 36/SF-36) and personality (NEO Five-Factor Inventory/NEOFFI) were assessed. Correlation and regression analyses were performed to determine associations between variables. RESULTS: A significant positive correlation existed between the FIS and EDSS (r=0.190; P<0.05). Significant negative correlations between the FIS with specific disease (FAMS mobility: r=-0.333, P<0.01; FAMS symptoms: r=-0.443, P<0.01; FAMS emotional well-being: r=-0.412, P<0.01; FAMS general contentment: r=-0.325, P<. 01; and, FAMS thinking/fatigue: r=-0.706, P<0.01); general disease (all domains SF36: -0.508Assuntos
Fadiga/etiologia
, Fadiga/psicologia
, Esclerose Múltipla/complicações
, Esclerose Múltipla/psicologia
, Qualidade de Vida/psicologia
, Adulto
, Cognição
, Feminino
, Humanos
, Masculino
, Pessoa de Meia-Idade
, Testes Neuropsicológicos
, Personalidade
, Análise de Regressão
RESUMO
Arrhythmogenic right ventricular cardiomyopathy (ARVC) is an important cause of malignant arrhythmia and sudden death particularly in young people. Although it is considered a desmosomal disease, mutations in non-desmosomal genes have also been identified. We report on a family where a mutation in LDB3 is associated with this condition. The index case and first and second degree relatives underwent a complete clinical evaluation: physical examination, electrocardiography (ECG), signal-averaged ECG, 2D echocardiogram, cardiac magnetic resonance and 24-h monitoring. After ruling out mutations in the five desmosomal genes, genetic testing by means of Next Generation Sequencing was carried out on the proband. A heterozygous missense mutation in LDB3 c.1051A>G was identified. This result was confirmed by subsequent Sanger DNA sequencing. Another six carriers were identified amongst her relatives. Three subjects fulfilled the criteria for a definitive diagnosis of ARVC and one reached a borderline diagnosis. In conclusion, this is the first family with ARVC where a mutation in LDB3 is associated with ARVC. Next generation sequencing arises as a particular useful tool to point to new causative genes in ARVC.
Assuntos
Proteínas Adaptadoras de Transdução de Sinal/genética , Arritmias Cardíacas/genética , Displasia Arritmogênica Ventricular Direita/genética , Proteínas com Domínio LIM/genética , Adolescente , Adulto , Displasia Arritmogênica Ventricular Direita/diagnóstico , Bloqueio de Ramo/diagnóstico , Bloqueio de Ramo/genética , Desmossomos/genética , Eletrocardiografia , Família , Feminino , Estudos de Associação Genética , Testes Genéticos , Sequenciamento de Nucleotídeos em Larga Escala , Humanos , Masculino , Pessoa de Meia-Idade , Mutação de Sentido Incorreto/genética , LinhagemRESUMO
OBJECTIVE: To present our experience with the implementation of a donation protocol following controlled cardiac death (Maastricht type III donation). DESIGN: A retrospective descriptive and observational study was made. SETTING: Intensive Care Unit of a third-level university hospital. PATIENTS: Eight patients in an irreversible state, in which withdrawal of all life support had been agreed, were evaluated as potential donors. INTERVENTIONS: Application of the adopted protocol. VARIABLES OF INTEREST: Clinical data of donors, evaluation of a donation protocol following cardiac death, warm ischemia times, and short-term outcome of the recipients. RESULTS: Eight patients were evaluated. In one case donation was not possible because no cardiac arrest developed in the 120 minutes after extubation. The 7 remaining patients were effective kidney donors. Warm ischemia times were less than 23 minutes in all cases. Although 7 of the 14 recipients suffered delayed graft function, all of them achieved good renal function. CONCLUSION: Donation after cardiac death in patients in an overwhelming and irreversible state represents a potential source of donors not previously considered in this country. The prior development of a consensus-based protocol can help increase the number of organs in combination with those obtained after brain death. In our experience, the results of kidney transplants obtained from donors after cardiac death are good, and the success of these types of protocols could be extended to other organs such as the liver and lungs.
Assuntos
Morte , Obtenção de Tecidos e Órgãos/classificação , Obtenção de Tecidos e Órgãos/normas , Idoso , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Guias de Prática Clínica como Assunto , Estudos RetrospectivosRESUMO
During the early stages of gastrulation in Drosophila embryo, the epithelial cells composing the single tissue layer of the egg undergo large strains and displacements. These movements have been usually modelled by decomposing the total deformation gradient in an (imposed or strain/stress dependent) active part and a passive response. Although the influence of the chemical and genetic activity in the mechanical response of the cell has been experimentally observed, the effects of the mechanical deformation on the latter have been far less studied, and much less modelled. Here, we propose a model that couples morphogen transport and the cell mechanics during embryogenesis. A diffusion-reaction equation is introduced as an additional mechanical regulator of morphogenesis. Consequently, the active deformations are not directly imposed in the analytical formulation, but they rather depend on the morphogen concentration, which is introduced as a new variable. In this study, we show that strain patterns similar to those observed during biological experiments can be reproduced by properly combining the two phenomena. In addition, we use a novel technique to parameterise the embryo geometry by solving two Laplace problems with specific boundary conditions. We apply the method to two morphogenetic movements: ventral furrow invagination and germ band extension. The matching between our results and the observed experimental deformations confirms that diffusion-reaction of morphogens can actually be controlling large morphogenetic movements.
Assuntos
Drosophila/embriologia , Desenvolvimento Embrionário , Modelos Biológicos , Animais , Fenômenos Biomecânicos , MorfogêneseRESUMO
BACKGROUND: The clinical analyses of free-ranging New World primates are extremely limited. The aim of this study was to obtain baseline data of blood chemistry and hematological values of free-ranging Alouatta pigra. METHOD: 17 males and 17 females were captured. We collected blood from the caudal tail vein; conventional techniques were used to analyze the samples RESULTS: Hemoglobin, hematocrit, and erythrocytes were significantly higher in males than in females. In relation to biochemical blood values, albumin/globulin ratio, cholesterol, triglycerides, calcium, phosphorus, magnesium, and iron were significantly higher in males than in females, while creatinine was significantly higher in females than in males. CONCLUSIONS: In general, measured parameters are similar to those of other primates and will be used as reference values for futures studies.
Assuntos
Alouatta/sangue , Espécies em Perigo de Extinção , Animais , Contagem de Células Sanguíneas , Feminino , Masculino , México , Valores de ReferênciaRESUMO
We present the case of a 63-year-old woman with a short patent ductus arteriosus and aneurysmal pulmonary arteries who was treated by placement of a stent-graft. The technique proved simple and safe. Further research is required to improve the design of stent-grafts and their release system for use of this technique in adult patients with this disorder.
Assuntos
Implante de Prótese Vascular/métodos , Permeabilidade do Canal Arterial/cirurgia , Stents , Angiografia , Feminino , Humanos , Pessoa de Meia-Idade , Tomografia Computadorizada por Raios XRESUMO
We report the case of a 29-year-old man with hemoptysis. The patient came to the emergency department, where a laboratory test and chest radiograph were reported as normal. The following day the patient again had hemoptysis, though less than previously. He reported no chest pain, dyspnea, fever, catarrh, changes in urine or feces, contact with patients with bacillus disease or constitutional symptoms. Doppler ultrasound of the chest showed right basal parenchymatous condensation containing a vessel with arterial flow (in the opposite direction to the aortic flow) compatible with an aberrant vessel, possibly a sequestration, leaving the aorta above the celiac trunk. Because of the findings of the chest echogram and magnetic resonance study, thoracoabdominal computed tomography angiography was undertaken; this showed right basal condensation and an anomalous vessel originating 1 cm above the celiac trunk, supplying the right lower lobe. An aortic and pulmonary arteriogram via an arterial and right femoral vein approach confirmed the findings. The patient was treated successfully with percutaneous embolization with coils. The relevant literature is reviewed.
Assuntos
Embolização Terapêutica/métodos , Hemoptise/terapia , Artéria Pulmonar/anormalidades , Adulto , Angiografia , Broncoscopia , Diagnóstico Diferencial , Hemoptise/diagnóstico , Humanos , Imageamento por Ressonância Magnética , Masculino , Tomografia Computadorizada por Raios X , Ultrassonografia DopplerRESUMO
The aim of this paper is to analyze the influence and differential weight of some specific psychological variables on adolescent antisocial behavior. A sample of 1,851 adolescents (49.92 % men and 50.08 % women) from the Autonomous Community of Madrid was assessed. Several stepwise regression analyses were conducted, considering three different age groups (14-15, 16 and 17-18 years), with the criterion variables and the results showed that the main psychological risk factors associated with antisocial behavior were variables linked to sensation seeking construct (impulsiveness, disinhibition, excitement seeking, etc.), while the protective factors identified were variables such as empathy and religious practices. The age groups were considered, keeping a design of optimum prevention programs with psychological character in mind.
Assuntos
Transtorno da Personalidade Antissocial/prevenção & controle , Transtorno da Personalidade Antissocial/psicologia , Adolescente , Transtorno da Personalidade Antissocial/diagnóstico , Comportamento Exploratório , Feminino , Humanos , Masculino , Psicologia , Análise de Regressão , Fatores de Risco , Inquéritos e QuestionáriosRESUMO
BACKGROUND: Advanced age, major orthopedic surgery, neoplastic disease, prolonged operations, varicose veins, immobilization, estrogen-containing medications, and obesity are known risk factors for the development of postoperative thromboembolic complications. Perioperative heparin is useful for reducing the incidence of deep venous thrombosis (DVT), but it is associated with a discrete bleeding rate. The purpose of this study was to determine the incidence of clinically evident DVT in morbidly obese patients after laparoscopic Roux-en-Y gastric bypass when a pneumatic compression hose is used as the only prophylaxis against DVT instead of anticoagulants. METHODS: From April 2000 to April 2003, 380 patients underwent laparoscopic Roux-en-Y gastric bypass for morbid obesity by one surgeon (R.H.C.). Prospectively, each patient was clinically evaluated for the presence of DVT during the postoperative period. Calf-length pneumatic compression stockings were placed before the procedure began, and remained in place until the patient was ambulatory. Ambulation was encouraged on the evening of the operation. No pharmacologic anticoagulant was used as a prophylaxis against DVT. RESULTS: Of the 380 patients, 346 were women and 34 were men with a mean age of 39.3 +/- 9.4 years (range, 14-65 years). The mean weight of these patients was 299.5 +/- 53.6 lb (range, 188-483 lb), and their mean body mass index was 48.5 +/- 6.6 (range, 36-70). The mean operative time was 103. 3 +/- 24.3 min (range, 62-227 min), and mean American Society of Anesthesiology (ASA) score was 2.6. Nine patients had clinical evidence of severe, chronic venous disease preoperatively. One patient (0.26%) experienced a clinically evident DVT limited to the popliteal vein on duplex ultrasonography. The clot resolved completely, as evidenced by follow-up duplex ultrasonography after 2 weeks of subcutaneously injected fractionated heparin. No clinically evident pulmonary thromboembolism occurred in this study group. CONCLUSIONS: The incidence of clinically evident DVT after laparoscopic Roux-en-Y gastric bypass is low when the procedure is accomplished with a relatively short operative time, with the initiation of calf-length pneumatic compression hose before the induction of anesthesia, and with routine early ambulation. No form of heparin anticoagulation is mandatory when these conditions can be met.
Assuntos
Bandagens , Derivação Gástrica/métodos , Laparoscopia/métodos , Complicações Pós-Operatórias/epidemiologia , Trombose Venosa/epidemiologia , Adolescente , Adulto , Idoso , Anastomose em-Y de Roux/métodos , Suscetibilidade a Doenças , Feminino , Humanos , Incidência , Masculino , Pessoa de Meia-Idade , Obesidade Mórbida/complicações , Obesidade Mórbida/cirurgia , Complicações Pós-Operatórias/etiologia , Complicações Pós-Operatórias/prevenção & controle , Estudos Prospectivos , Resultado do Tratamento , Trombose Venosa/etiologia , Trombose Venosa/prevenção & controleAssuntos
Citrobacter freundii , Infecções por Enterobacteriaceae/transmissão , Síndrome do Desconforto Respiratório do Recém-Nascido/microbiologia , Antibacterianos/uso terapêutico , Ciprofloxacina/uso terapêutico , Infecções por Enterobacteriaceae/tratamento farmacológico , Humanos , Recém-Nascido , Transmissão Vertical de Doenças Infecciosas , Síndrome do Desconforto Respiratório do Recém-Nascido/tratamento farmacológicoRESUMO
A 5-week-old-infant presented to hospital following the acute onset of non-bilious vomiting with clinical and acid-base features suggestive of pyloric stenosis. A chest radiograph obtained because of intercurrent infection unexpectedly revealed a left-sided congenital diaphragmatic hernia. A barium meal demonstrated the presence of an intrathoracic gastric volvulus, requiring urgent surgical management. We discuss the presentation and management of this rare surgical cause of non-bilious vomiting in infancy.
Assuntos
Hérnia Diafragmática/diagnóstico , Estenose Pilórica/diagnóstico , Volvo Gástrico/diagnóstico , Abdome Agudo/diagnóstico , Diagnóstico Diferencial , Procedimentos Cirúrgicos do Sistema Digestório , Seguimentos , Hérnia Diafragmática/cirurgia , Hérnias Diafragmáticas Congênitas , Humanos , Recém-Nascido , Masculino , Estenose Pilórica/diagnóstico por imagem , Radiografia , Medição de Risco , Volvo Gástrico/diagnóstico por imagem , Volvo Gástrico/cirurgia , Resultado do TratamentoRESUMO
The administration of adenosine during atrial tachycardia usually terminates the arrhythmia or induces AV block and makes the diagnosis clear. We present a patient with atrial tachycardia in which the administration of adenosine induced a transient atrial fibrillation (AF). A continuous transition between both arrhythmias was observed and the original tachycardia persisted after the termination of the AF. This proarrhythmic effect may be due to the adenosine-mediated shortening of the atrial refractory periods, which produces a decreased wavelength of the reentry circuits and the potential coexistence of several wave-fronts in the atria, favoring the development of AF. The recognition of this uncommon effect is important, since the repeated administration of increasing doses of adenosine may induce sustained AF.
Assuntos
Adenosina/efeitos adversos , Antiarrítmicos/efeitos adversos , Fibrilação Atrial/induzido quimicamente , Taquicardia Supraventricular/tratamento farmacológico , Adenosina/uso terapêutico , Amiodarona/uso terapêutico , Antiarrítmicos/uso terapêutico , Fibrilação Atrial/etiologia , Fibrilação Atrial/fisiopatologia , Eletrocardiografia , Feminino , Humanos , Pessoa de Meia-Idade , Taquicardia Supraventricular/complicações , Complexos Ventriculares Prematuros/etiologiaRESUMO
We previously published study results stating that the early rat fetal liver contains a high frequency of T/dendritic cells (DCs), but rarely T/NK bipotent common progenitors. Now, by using xenogenic rat/SCID mouse fetal thymic organ cultures, we extend these observations to the thymus, in which conflicting data have been published in human and mouse. On the one hand, enriched adult intrathymic CD45+CD2- triple negative for CD8, CD4, and CD3 Ag cell progenitors, which contained both rearranged TCRbeta chain and pre-Talpha chain transcripts, completely lacked NKR-P1A expressing cells, and upon limiting dilution conditions, generated T- and T/DC-containing lobes, but no T/NK or NK ones were found. On the other hand, the CD45+CD2- triple negative for CD8, CD4, and CD3 Ags cell population obtained from 15- and 16-day-old fetal rat thymus can be divided into NKR-P1A- and NKR-P1A(low) cell subpopulations that differ in several aspects. Both cell subsets expressed pre-TCRalpha chain transcripts, but only the former contained fully rearranged TCRbeta chain transcripts. Upon limiting dilution, T cell-committed progenitors were only found in the NKR-P1A- cell population, whereas NK-committed progenitors were present in the NKR-P1A(low) population. More importantly, bipotential T/NK progenitors were very rare and were found only in the NKR-P1A(low) cell population, whereas bipotential T/DC progenitors, only previously suggested in the adult mouse thymus, were observed frequently in the NKR-P1A-CD2- cell subpopulation. Our results demonstrate, therefore, that a common intrathymic T/DC intermediate represents the main T cell developmental pathway in rat thymus.
Assuntos
Células Dendríticas/imunologia , Células Matadoras Naturais/imunologia , Lectinas Tipo C , Linfócitos T/imunologia , Timo/embriologia , Timo/imunologia , Animais , Antígenos de Superfície/análise , Antígenos CD2/análise , Linhagem da Célula , Células Cultivadas , Imunofenotipagem , Antígenos Comuns de Leucócito/análise , Camundongos , Camundongos SCID , Subfamília B de Receptores Semelhantes a Lectina de Células NK , RNA Mensageiro/biossíntese , Ratos , Ratos Wistar , Receptores de Antígenos de Linfócitos T alfa-beta/biossíntese , Receptores de Antígenos de Linfócitos T alfa-beta/genética , Células-Tronco/classificação , Células-Tronco/imunologiaRESUMO
INTRODUCTION AND OBJECTIVES: The induction of ventricular arrhythmias by appropriate antibradycardia ventricular pacing in patients with implantable cardioverter defibrillators has been reported in only a few cases. The aim of this study was to assess the incidence, characteristics and management of these episodes. METHODS: The follow-up records of 180 patients with implantable cardioverter defibrillators with intracardiac electrogram storage were reviewed. Pacing induced episodes were defined as those occurring immediately after an appropriate paced stimulus in a patient with sporadic paced beats. We assessed the number and type of episodes, mode of onset, therapy administered and the efficacy of different prevention measures. RESULTS: Pacing induced episodes were found in 9 patients (5%). Seven received device administered therapy which was effective in all cases. One to 95 episodes were observed per patient, of which 138 were monomorphic ventricular tachycardias and 20 polymorphic ventricular tachycardia/ventricular fibrillation episodes. All were induced by a paced ventricular beat after a post-extrasystolic pause or after long RR intervals during atrial fibrillation. Pacing induced arrhythmias were prevented by changing the pacing rate or hysteresis in 3 out of 6 patients and by decreasing the stimulus energy in 3 out of 3. Antibradycardia pacing function was disabled in 4 patients. CONCLUSIONS: Ventricular arrhythmias induced by appropriate antibradycardia ventricular pacing are relatively common in patients with implantable cardioverter defibrillators. Effective prevention can be achieved in most cases by changing the pacing rate or the pacing stimulus energy, however in selected cases the antibradycardia function may be disabled.