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1.
BMC Cardiovasc Disord ; 21(1): 81, 2021 02 09.
Artículo en Inglés | MEDLINE | ID: mdl-33563223

RESUMEN

BACKGROUND: Myocardial iron overload in patients with thalassemia major (TM) is one of the most important complications. The purpose of the study was to identify advanced echocardiography parameters for early identification of myocardial dysfunction during follow-up of patients with TM. METHODS: Forty TM patients who were 41 ± 5 years old were included in the study and divided into two groups according to cardiac magnetic resonance T2* results (Group 1: Τ2* > 25 ms, Group 2: Τ2* ≤ 25 ms). Liver T2* parameters were also measured. Conventional and deformational echocardiographic parameters were measured at baseline and approximately 2 years later. RESULTS: Thirty-two patients had Τ2* = 34 ± 4 ms (Group 1), and 8 had Τ2* = 17 ± 9 ms (Group 2). Blood consumption was 185 ± 60 and 199 ± 37 ml/kg/yr (p = 0.64), and liver T2* was 4 ± 5 and 17 ± 21 ms (p = 0.01) in Groups 1 and 2, respectively. At baseline, Group 1 had better left ventricular global longitudinal strain (GLS) (- 22 ± 3 vs. - 18 ± 5, p = 0.01) and similar left ventricular ejection fraction (LVEF) (62 ± 5% vs. 58 ± 10%, p = 0.086) than Group 2. At the 28 ± 11-month follow-up, LVEF, GLS, and T2* values in Group 1 (63 ± 3%, - 21 ± 3%, 34 ± 4 ms) and Group 2 (56 ± 11%, - 17 ± 4%, 17 ± 9 ms) did not change significantly compared to their corresponding baseline values. In 8 patients from Group 1, a worsening (> 15%) in LS (p = 0.001) was detected during follow-up, with a marginal reduction in LVEF. CONCLUSIONS: GLS seems to be an efficient echocardiographic parameter for detecting hemochromatosis-related cardiac dysfunction earlier than LVEF. It also seems to be affected by other factors (free radical oxygen, immunogenetic mechanisms or viral infections) in a minority of patients, underscoring the multifactorial etiology of cardiomyopathy.


Asunto(s)
Transfusión Sanguínea , Hemocromatosis/etiología , Volumen Sistólico , Disfunción Ventricular Izquierda/etiología , Función Ventricular Izquierda , Talasemia beta/terapia , Adulto , Ecocardiografía Doppler , Femenino , Hemocromatosis/diagnóstico , Humanos , Imagen por Resonancia Magnética , Masculino , Persona de Mediana Edad , Estudios Retrospectivos , Factores de Riesgo , Factores de Tiempo , Resultado del Tratamiento , Disfunción Ventricular Izquierda/diagnóstico por imagen , Disfunción Ventricular Izquierda/fisiopatología , Talasemia beta/diagnóstico
2.
Heart Fail Rev ; 25(6): 927-935, 2020 11.
Artículo en Inglés | MEDLINE | ID: mdl-31641978

RESUMEN

Congestion is one of the most prominent characteristics of patients presented with decompensated heart failure and it implies unfavorable prognosis for the heart failure patient. Neurohumoral and immuno-inflammatory activation secondary to cardiac dysfunction constitute the pivotal mechanisms driving the heart failure syndrome that results in progressive fluid accumulation. In addition, fluid redistribution between different vascular compartments in human body guided from sympathetic activity constitutes another mechanism for heart failure decompensation. Ultrasound applied in the form of echocardiography provides invaluable data for the assessment of intracardiac filling pressures. The type of renal venous flow can provide the degree of renal congestion and probably insight into the pathophysiology of the decompensation of heart failure. Assessment of lung congestion in the patient with heart failure can be accomplished by lung ultrasonography. Additionally, clinical studies on the role of ultrasound in the management and prognosis of the congested patient are reviewed. Special heart failure population supported with left ventricular assist devices and extracorporeal membrane oxygenation support constitute an area where ultrasound guidance of fluid management has gained important role.


Asunto(s)
Manejo de la Enfermedad , Insuficiencia Cardíaca/terapia , Ventrículos Cardíacos/diagnóstico por imagen , Ultrasonografía/métodos , Función Ventricular Izquierda/fisiología , Insuficiencia Cardíaca/diagnóstico , Insuficiencia Cardíaca/fisiopatología , Ventrículos Cardíacos/fisiopatología , Humanos
3.
J Thromb Thrombolysis ; 46(4): 516-520, 2018 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-30088118

RESUMEN

Pulmonary hypertension (PH), a serious disorder with a high morbidity and mortality rate, is known to occur in a number of unrelated systemic diseases. ß-Thalassaemia, among other haematological disorders, develop PH which is not an infrequent finding and worsens the prognosis. Haemolysis, iron overload and hypercoagulable state are among the main pathogenetic mechanisms. Haemoglobinopathies and congenital haemolytic anaemia constitute a unique patients population more predisposed to developing chronic thromboembolic pulmonary hypertension (CTEPH). Although pulmonary endarterectomy is accepted as the best treatment for CTEPH, surgery in these patients poses significant practical challenges given the distinct nature of the disease. As drug therapy is not expected to offer relief from the mechanical obstructions of pulmonary arteries and the use of specific pulmonary arterial hypertension drugs is not established in thalassaemia patients, the novel technique of balloon pulmonary angioplasty (BPA) may emerge as a new therapeutic option for patients with inoperable CTEPH and thalassaemia. We are reporting the case of a thalassaemic patient with a history of splenectomy suffering from progressive severe pulmonary hypertension related to chronic thromboembolic disease, who was successfully treated by BPA with substantial improvement.


Asunto(s)
Angioplastia de Balón , Hipertensión Pulmonar/cirugía , Arteria Pulmonar/cirugía , Talasemia/terapia , Tromboembolia/fisiopatología , Enfermedad Crónica , Humanos , Resultado del Tratamiento
4.
BMC Cardiovasc Disord ; 14: 78, 2014 Jun 23.
Artículo en Inglés | MEDLINE | ID: mdl-24958250

RESUMEN

BACKGROUND: Electronic cigarettes have been developed and marketed in recent years as smoking substitutes. However, no studies have evaluated their effects on the cardiovascular system. The purpose of this study was to examine the immediate effects of electronic cigarette use on left ventricular (LV) function, compared to the well-documented acute adverse effects of smoking. METHODS: Echocardiographic examinations were performed in 36 healthy heavy smokers (SM, age 36 ± 5 years) before and after smoking 1 cigarette and in 40 electronic cigarette users (ECIG, age 35 ± 5 years) before and after using the device with "medium-strength" nicotine concentration (11 mg/ml) for 7 minutes. Mitral flow diastolic velocities (E, A), their ratio (E/A), deceleration time (DT), isovolumetric relaxation time (IVRT) and corrected-to-heart rate IVRT (IVRTc) were measured. Mitral annulus systolic (Sm), and diastolic (Em, Am) velocities were estimated. Myocardial performance index was calculated from Doppler flow (MPI) and tissue Doppler (MPIt). Longitudinal deformation measurements of global strain (GS), systolic (SRs) and diastolic (SRe, SRa) strain rate were also performed. RESULTS: Baseline measurements were similar in both groups. In SM, IVRT and IVRTc were prolonged, Em and SRe were decreased, and both MPI and MPIt were elevated after smoking. In ECIG, no differences were observed after device use. Comparing after-use measurements, ECIG had higher Em (P = 0.032) and SRe (P = 0.022), and lower IVRTc (P = 0.011), MPI (P = 0.001) and MPIt (P = 0.019). The observed differences were significant even after adjusting for changes in heart rate and blood pressure. CONCLUSIONS: Although acute smoking causes a delay in myocardial relaxation, electronic cigarette use has no immediate effects. Electronic cigarettes' role in tobacco harm reduction should be studied intensively in order to determine whether switching to electronic cigarette use may have long-term beneficial effects on smokers' health. TRIAL REGISTRATION: Current Controlled Trials ISRCTN16974547.


Asunto(s)
Sistemas Electrónicos de Liberación de Nicotina , Nicotina/administración & dosificación , Agonistas Nicotínicos/administración & dosificación , Cese del Hábito de Fumar/métodos , Prevención del Hábito de Fumar , Tabaquismo/tratamiento farmacológico , Función Ventricular Izquierda/efectos de los fármacos , Administración por Inhalación , Adulto , Presión Sanguínea/efectos de los fármacos , Ecocardiografía Doppler , Sistemas Electrónicos de Liberación de Nicotina/efectos adversos , Femenino , Frecuencia Cardíaca/efectos de los fármacos , Humanos , Masculino , Válvula Mitral/efectos de los fármacos , Válvula Mitral/fisiopatología , Nicotina/efectos adversos , Agonistas Nicotínicos/efectos adversos , Factores de Riesgo , Fumar/efectos adversos , Fumar/fisiopatología , Factores de Tiempo , Tabaquismo/diagnóstico , Tabaquismo/fisiopatología
5.
J Clin Invest ; 111(6): 869-76, 2003 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-12639993

RESUMEN

In human disease and experimental animal models, depressed Ca(2+) handling in failing cardiomyocytes is widely attributed to impaired sarcoplasmic reticulum (SR) function. In mice, disruption of the PLN gene encoding phospholamban (PLN) or expression of dominant-negative PLN mutants enhances SR and cardiac function, but effects of PLN mutations in humans are unknown. Here, a T116G point mutation, substituting a termination codon for Leu-39 (L39stop), was identified in two families with hereditary heart failure. The heterozygous individuals exhibited hypertrophy without diminished contractile performance. Strikingly, both individuals homozygous for L39stop developed dilated cardiomyopathy and heart failure, requiring cardiac transplantation at ages 16 and 27. An over 50% reduction in PLN mRNA and no detectable PLN protein were noted in one explanted heart. The expression of recombinant PLN-L39stop in human embryonic kidney (HEK) 293 cells and adult rat cardiomyocytes showed no PLN inhibition of SR Ca(2+)-ATPase and the virtual absence of stable PLN expression; where PLN was expressed, it was misrouted to the cytosol or plasma membrane. These findings describe a naturally-occurring loss-of-function human PLN mutation (PLN null). In contrast to reported benefits of PLN ablation in mouse heart failure, humans lacking PLN develop lethal dilated cardiomyopathy.


Asunto(s)
Proteínas de Unión al Calcio/genética , Cardiomiopatía Dilatada/genética , Modelos Animales de Enfermedad , Mutación , Animales , Calcio/metabolismo , Proteínas de Unión al Calcio/fisiología , Cardiomiopatía Dilatada/etiología , Línea Celular , Insuficiencia Cardíaca/etiología , Humanos , Masculino , Ratones , Linaje , Ratas , Ratas Sprague-Dawley , Retículo Sarcoplasmático/metabolismo , Especificidad de la Especie
6.
Sci Rep ; 5: 13506, 2015 Sep 04.
Artículo en Inglés | MEDLINE | ID: mdl-26336999

RESUMEN

This Article contains a typographical error in the Methods section under the subheading "Materials and clinical procedure". "The results of the two tests after excluding the question on cigarette and EC consumption were also reported (as FTCD-modified and CDS-modified, Table 1)." should read: "The results of the two tests after excluding the question on cigarette and EC consumption were also reported (as FTCD-modified and CDS-modified, Table 2)."

7.
Sci Rep ; 5: 11269, 2015 Jun 17.
Artículo en Inglés | MEDLINE | ID: mdl-26082330

RESUMEN

Electronic cigarettes (ECs) are nicotine delivery devices that are proposed as tobacco harm reduction products to smokers. Nicotine delivery from ECs is potentially important in their efficacy as smoking substitutes. Herein, nicotine delivery from using a new-generation EC device (variable-wattage, set at 9 W) was evaluated, comparing experienced (vapers) with naïve users (smokers). Twenty-four vapers and 23 smokers participated to the study. They were asked to obtain 10 puffs in 5 minutes and then use the EC ad lib for 60 more minutes (total duration of use: 65 minutes). An 18 mg/mL nicotine-containing liquid was used. Blood samples were obtained at baseline, 5-minutes and every 15 minutes thereafter, while number of puffs and average puff duration were recorded. Although at baseline both groups had similar plasma nicotine levels, smokers consistently exhibited lower levels at all time-periods; at 5-minutes the levels were lower by 46%, while during the subsequent period they were lower by 43% (at 65-minutes) to 54% (at 20-minutes). Both groups took similar number of puffs, but smokers had average puff duration of 2.3 s compared to 3.5 s in vapers. Even in vapers, plasma nicotine levels at 5 minutes were lower than those observed after smoking 1 tobacco cigarette.


Asunto(s)
Sistemas Electrónicos de Liberación de Nicotina , Nicotina/metabolismo , Adsorción , Adulto , Femenino , Humanos , Masculino , Nicotina/sangre , Fumar , Tabaquismo
8.
Int J Environ Res Public Health ; 11(4): 4356-73, 2014 Apr 22.
Artículo en Inglés | MEDLINE | ID: mdl-24758891

RESUMEN

BACKGROUND: Electronic cigarette (EC) use has grown exponentially over the past few years. The purpose of this survey was to assess the characteristics and experiences of a large sample of EC users and examine the differences between those who partially and completely substituted smoking with EC use. METHODS: A questionnaire was prepared, translated into 10 different languages and uploaded in an online survey tool. EC users were asked to participate irrespective of their current smoking status. Participants were divided according to their smoking status at the time of participation in two subgroups: former smokers and current smokers. RESULTS: In total, 19,414 participants were included in the analysis, with 88 of them (0.5%) reported not being smokers at the time of EC use initiation. Complete substitution of smoking was reported by 81.0% of participants (former smokers) while current smokers had reduced smoking consumption from 20 to 4 cigarettes per day. They were using ECs for a median of 10 months. They initiated EC use with a median of 18 mg/mL nicotine-concentration liquids; 21.5% used higher than 20 mg/mL. Only 3.5% of participants were using 0-nicotine liquids at the time of the survey. Former smokers were highly dependent (Fagerström Test for Cigarette Dependence = 7) and were heavier smokers (21 cigarettes per day when smoking) compared to current smokers. The most important reasons for initiating EC use for both subgroups was to reduce the harm associated with smoking and to reduce exposure of family members to second-hand smoking. Most considered ECs as less harmful than tobacco cigarettes, while 11.0% considered them absolutely harmless. Side effects were reported by more than half of the participants (59.8%), with the most common being sore/dry mouth and throat; side effects were mild and in most cases were subsequently resolved (partially or completely). Participants experienced significant benefits in physical status and improvements in pre-existing disease conditions (including respiratory disease such as asthma and chronic obstructive lung disease). Being former smoker was independently associated with positive effects in health and improvements in disease conditions. CONCLUSIONS: The results of this worldwide survey of dedicated users indicate that ECs are mostly used to avoid the harm associated with smoking. They can be effective even in highly-dependent smokers and are used as long-term substitutes for smoking. High levels of nicotine are used at initiation; subsequently, users try to reduce nicotine consumption, with only a small minority using non-nicotine liquids. Side effects are minor and health benefits are substantial, especially for those who completely substitute smoking with EC use. Further population and interventional studies are warranted.


Asunto(s)
Equipos y Suministros Eléctricos , Productos de Tabaco , Dispositivos para Dejar de Fumar Tabaco/estadística & datos numéricos , Adulto , Humanos , Masculino , Persona de Mediana Edad , Percepción , Fumar/psicología , Cese del Hábito de Fumar/métodos , Cese del Hábito de Fumar/psicología , Cese del Hábito de Fumar/estadística & datos numéricos , Encuestas y Cuestionarios , Productos de Tabaco/efectos adversos , Tabaquismo/psicología
9.
Subst Abuse ; 7: 139-46, 2013.
Artículo en Inglés | MEDLINE | ID: mdl-24049448

RESUMEN

BACKGROUND: Electronic cigarettes (ECs) are alternative-to-smoking nicotine delivery devices; consumers (commonly called vapers) use them in order to reduce or completely substitute smoking. The European Commission has released a proposal for a new Tobacco Product Directive that might reduce availability of nicotine-containing products, including ECs. In this study, the EC use patterns in subjects who have completely substituted smoking with EC use were examined by personal interviews. The study focused on nicotine levels used in order to achieve smoking cessation, reported benefits, associated side effects, and estimation of EC dependence compared with smoking. METHODS: Participants were 111 subjects who had completely substituted smoking with EC use for at least 1 month. Smoking abstinence was validated by measuring blood carboxyhemoglobin levels. Nicotine levels at initiation of EC use, at time of smoking cessation, and at time of interview were recorded. Dependence potential was assessed by asking the first question of the Fagerström Test for Cigarette Dependence (time until smoking the first cigarette and until first use of EC in the morning) and questions about perceived past dependence on tobacco cigarettes and present dependence on EC. RESULTS: Forty-two percent of participants reported quitting smoking during the first month of EC use. Liquids with nicotine concentration >15 mg/mL were used by 74% of users at initiation of EC use, while 16.2% had to increase the initial nicotine levels in order to achieve complete smoking abstinence. Seventy-two participants (64.9%) reported that from the time of smoking cessation to the time of the interview (8 months median duration of EC use) they reduced the nicotine concentration they were consuming; however, only 12% of the total sample was using ≤5 mg/mL nicotine concentration at the time of the interview. Side effects were mild and temporary. The vast majority of participants reported better exercise capacity and improved olfactory and gustatory senses. Perceived EC dependenct was significantly lower compared to smoking. CONCLUSIONS: Nicotine levels appear to play an important role in achieving and maintaining smoking cessation in the group of motivated subjects studied. High nicotine-containing liquids were used while few mild and temporary side effects were reported. Proposals about regulation should consider the pragmatic use patterns of ECs, especially in consumers who have completely substituted smoking.

10.
Int J Environ Res Public Health ; 10(6): 2500-14, 2013 Jun 18.
Artículo en Inglés | MEDLINE | ID: mdl-23778060

RESUMEN

BACKGROUND: Although millions of people are using electronic cigarettes (ECs) and research on this topic has intensified in recent years, the pattern of EC use has not been systematically studied. Additionally, no comparative measure of exposure and nicotine delivery between EC and tobacco cigarette or nicotine replacement therapy (NRTs) has been established. This is important, especially in the context of the proposal for a new Tobacco Product Directive issued by the European Commission. METHODS: A second generation EC device, consisting of a higher capacity battery and tank atomiser design compared to smaller cigarette-like batteries and cartomizers, and a 9 mg/mL nicotine-concentration liquid were used in this study. Eighty subjects were recruited; 45 experienced EC users and 35 smokers. EC users were video-recorded when using the device (ECIG group), while smokers were recorded when smoking (SM-S group) and when using the EC (SM-E group) in a randomized cross-over design. Puff, inhalation and exhalation duration were measured. Additionally, the amount of EC liquid consumed by experienced EC users was measured at 5 min (similar to the time needed to smoke one tobacco cigarette) and at 20 min (similar to the time needed for a nicotine inhaler to deliver 4 mg nicotine). RESULTS: Puff duration was significantly higher in ECIG (4.2 ± 0.7 s) compared to SM-S (2.1 ± 0.4 s) and SM-E (2.3 ± 0.5 s), while inhalation time was lower (1.3 ± 0.4, 2.1 ± 0.4 and 2.1 ± 0.4 respectively). No difference was observed in exhalation duration. EC users took 13 puffs and consumed 62 ± 16 mg liquid in 5 min; they took 43 puffs and consumed 219 ± 56 mg liquid in 20 min. Nicotine delivery was estimated at 0.46 ± 0.12 mg after 5 min and 1.63 ± 0.41 mg after 20 min of use. Therefore, 20.8 mg/mL and 23.8 mg/mL nicotine-containing liquids would deliver 1 mg of nicotine in 5 min and 4 mg nicotine in 20 min, respectively. Since the ISO method significantly underestimates nicotine delivery by tobacco cigarettes, it seems that liquids with even higher than 24 mg/mL nicotine concentration would be comparable to one tobacco cigarette. CONCLUSIONS: EC use topography is significantly different compared to smoking. Four-second puffs with 20-30 s interpuff interval should be used when assessing EC effects in laboratory experiments, provided that the equipment used does not get overheated. Based on the characteristics of the device used in this study, a 20 mg/mL nicotine concentration liquid would be needed in order to deliver nicotine at amounts similar to the maximum allowable content of one tobacco cigarette (as measured by the ISO 3308 method). The results of this study do not support the statement of the European Commission Tobacco Product Directive that liquids with nicotine concentration of 4 mg/mL are comparable to NRTs in the amount of nicotine delivered to the user.


Asunto(s)
Sistemas de Liberación de Medicamentos/normas , Nebulizadores y Vaporizadores , Nicotina/administración & dosificación , Salud Pública/legislación & jurisprudencia , Fumar/legislación & jurisprudencia , Productos de Tabaco , Administración por Inhalación , Adulto , Estudios Cruzados , Sistemas de Liberación de Medicamentos/instrumentación , Unión Europea , Femenino , Humanos , Masculino , Persona de Mediana Edad , Fumar/sangre , Adulto Joven
11.
Int J Environ Res Public Health ; 10(12): 7272-82, 2013 Dec 17.
Artículo en Inglés | MEDLINE | ID: mdl-24351746

RESUMEN

BACKGROUND: A major characteristic of the electronic cigarette (EC) market is the availability of a large number of different flavours. This has been criticised by the public health authorities, some of whom believe that diverse flavours will attract young users and that ECs are a gateway to smoking. At the same time, several reports in the news media mention that the main purpose of flavour marketing is to attract youngsters. The importance of flavourings and their patterns of use by EC consumers have not been adequately evaluated, therefore, the purpose of this survey was to examine and understand the impact of flavourings in the EC experience of dedicated users. METHODS: A questionnaire was prepared and uploaded in an online survey tool. EC users were asked to participate irrespective of their current smoking status. Participants were divided according to their smoking status at the time of participation in two subgroups: former smokers and current smokers. RESULTS: In total, 4,618 participants were included in the analysis, with 4,515 reporting current smoking status. The vast majority (91.1%) were former smokers, while current smokers had reduced smoking consumption from 20 to 4 cigarettes per day. Both subgroups had a median smoking history of 22 years and had been using ECs for 12 months. On average they were using three different types of liquid flavours on a regular basis, with former smokers switching between flavours more frequently compared to current smokers; 69.2% of the former subgroup reported doing so on a daily basis or within the day. Fruit flavours were more popular at the time of participation, while tobacco flavours were more popular at initiation of EC use. On a scale from 1 (not at all important) to 5 (extremely important) participants answered that variability of flavours was "very important" (score = 4) in their effort to reduce or quit smoking. The majority reported that restricting variability will make ECs less enjoyable and more boring, while 48.5% mentioned that it would increase craving for cigarettes and 39.7% said that it would have been less likely for them to reduce or quit smoking. The number of flavours used was independently associated with smoking cessation. CONCLUSIONS: The results of this survey of dedicated users indicate that flavours are marketed in order to satisfy vapers' demand. They appear to contribute to both perceived pleasure and the effort to reduce cigarette consumption or quit smoking. Due to the fact that adoption of ECs by youngsters is currently minimal, it seems that implementing regulatory restrictions to flavours could cause harm to current vapers while no public health benefits would be observed in youngsters. Therefore, flavours variability should be maintained; any potential future risk for youngsters being attracted to ECs can be sufficiently minimized by strictly prohibiting EC sales in this population group.


Asunto(s)
Fumar/psicología , Gusto , Dispositivos para Dejar de Fumar Tabaco/estadística & datos numéricos , Adulto , Femenino , Humanos , Internet , Masculino , Autoinforme , Fumar/epidemiología , Encuestas y Cuestionarios
12.
Int J Environ Res Public Health ; 10(10): 5146-62, 2013 Oct 16.
Artículo en Inglés | MEDLINE | ID: mdl-24135821

RESUMEN

BACKGROUND: Electronic cigarettes (ECs) have been marketed as an alternative-to-smoking habit. Besides chemical studies of the content of EC liquids or vapour, little research has been conducted on their in vitro effects. Smoking is an important risk factor for cardiovascular disease and cigarette smoke (CS) has well-established cytotoxic effects on myocardial cells. The purpose of this study was to evaluate the cytotoxic potential of the vapour of 20 EC liquid samples and a "base" liquid sample (50% glycerol and 50% propylene glycol, with no nicotine or flavourings) on cultured myocardial cells. Included were 4 samples produced by using cured tobacco leaves in order to extract the tobacco flavour. METHODS: Cytotoxicity was tested according to the ISO 10993-5 standard. By activating an EC device at 3.7 volts (6.2 watts-all samples, including the "base" liquid) and at 4.5 volts (9.2 watts-four randomly selected samples), 200 mg of liquid evaporated and was extracted in 20 mL of culture medium. Cigarette smoke (CS) extract from three tobacco cigarettes was produced according to ISO 3308 method (2 s puffs of 35 mL volume, one puff every 60 s). The extracts, undiluted (100%) and in four dilutions (50%, 25%, 12.5%, and 6.25%), were applied to myocardial cells (H9c2); percent-viability was measured after 24 h incubation. According to ISO 10993-5, viability of <70% was considered cytotoxic. RESULTS: CS extract was cytotoxic at extract concentrations >6.25% (viability: 76.9 ± 2.0% at 6.25%, 38.2 ± 0.5% at 12.5%, 3.1 ± 0.2% at 25%, 5.2 ± 0.8% at 50%, and 3.9 ± 0.2% at 100% extract concentration). Three EC extracts (produced by tobacco leaves) were cytotoxic at 100% and 50% extract concentrations (viability range: 2.2%-39.1% and 7.4%-66.9% respectively) and one ("Cinnamon-Cookies" flavour) was cytotoxic at 100% concentration only (viability: 64.8 ± 2.5%). Inhibitory concentration 50 was >3 times lower in CS extract compared to the worst-performing EC vapour extract. For EC extracts produced by high-voltage and energy, viability was reduced but no sample was cytotoxic according to ISO 10993-5 definition. Vapour produced by the "base" liquid was not cytotoxic at any extract concentration. Cell survival was not associated with nicotine concentration of EC liquids. CONCLUSIONS: This study indicates that some EC samples have cytotoxic properties on cultured cardiomyoblasts, associated with the production process and materials used in flavourings. However, all EC vapour extracts were significantly less cytotoxic compared to CS extract.


Asunto(s)
Sistemas de Liberación de Medicamentos , Gases/farmacología , Mioblastos Cardíacos/efectos de los fármacos , Humo/efectos adversos , Animales , Línea Celular , Gases/administración & dosificación , Nicotina/administración & dosificación , Nicotina/farmacología , Ratas , Humo/análisis , Nicotiana/química , Productos de Tabaco/análisis
16.
Proc Natl Acad Sci U S A ; 103(5): 1388-93, 2006 Jan 31.
Artículo en Inglés | MEDLINE | ID: mdl-16432188

RESUMEN

The sarcoplasmic reticulum Ca(2+)-cycling proteins are key regulators of cardiac contractility, and alterations in sarcoplasmic reticulum Ca(2+)-cycling properties have been shown to be causal of familial cardiomyopathies. Through genetic screening of dilated cardiomyopathy patients, we identified a previously uncharacterized deletion of arginine 14 (PLN-R14Del) in the coding region of the phospholamban (PLN) gene in a large family with hereditary heart failure. No homozygous individuals were identified. By middle age, heterozygous individuals developed left ventricular dilation, contractile dysfunction, and episodic ventricular arrhythmias, with overt heart failure in some cases. Transgenic mice overexpressing the mutant PLN-R14Del recapitulated human cardiomyopathy exhibiting similar histopathologic abnormalities and premature death. Coexpression of the normal and mutant-PLN in HEK-293 cells resulted in sarcoplasmic reticulum Ca(2+)-ATPase superinhibition. The dominant effect of the PLN-R14Del mutation could not be fully removed, even upon phosphorylation by protein kinase A. Thus, by chronic suppression of sarcoplasmic reticulum Ca(2+)-ATPase activity, the nonreversible superinhibitory function of mutant PLN-R14Del may lead to inherited dilated cardiomyopathy and premature death in both humans and mice.


Asunto(s)
Arginina/genética , Proteínas de Unión al Calcio/genética , Cardiomiopatías/genética , Cardiomiopatías/mortalidad , Mutación , Adulto , Animales , Arritmias Cardíacas/metabolismo , Calcio/química , Proteínas de Unión al Calcio/metabolismo , Línea Celular , Niño , Análisis Mutacional de ADN , Ecocardiografía , Salud de la Familia , Femenino , Eliminación de Gen , Heterocigoto , Homocigoto , Humanos , Masculino , Ratones , Ratones Transgénicos , Microscopía Fluorescente , Persona de Mediana Edad , Modelos Estadísticos , Linaje , Retículo Sarcoplasmático/metabolismo , Factores de Tiempo
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