985 resultados para HEART ARREST, INDUCED
Resumo:
Aim. The aim of this study was to understand the heart transplantation experience based on patients` descriptions. Background. To patients with heart failure, heart transplantation represents a possibility to survive and improve their quality of life. Studies have shown that more quality of life is related to patients` increasing awareness and participation in the work of the healthcare team in the post-transplantation period. Deficient relationships between patients and healthcare providers result in lower compliance with the postoperative regimen. Method. A phenomenological approach was used to interview 26 patients who were heart transplant recipients. Patients were interviewed individually and asked this single question: What does the experience of being heart transplanted mean? Participants` descriptions were analysed using phenomenological reduction, analysis and interpretation. Results. Three categories emerged from data analysis: (i) the time lived by the heart recipient; (ii) donors, family and caregivers and (iii) reflections on the experience lived. Living after heart transplant means living in a complex situation: recipients are confronted with lifelong immunosuppressive therapy associated with many side-effects. Some felt healthy whereas others reported persistence of complications as well as the onset of other pathologies. However, all participants celebrated an improvement in quality of life. Health caregivers, their social and family support had been essential for their struggle. Participants realised that life after heart transplantation was a continuing process demanding support and structured follow-up for the rest of their lives. Conclusion. The findings suggest that each individual has unique experiences of the heart transplantation process. To go on living participants had to accept changes and adapt: to the organ change, to complications resulting from rejection of the organ, to lots of pills and food restrictions. Relevance to clinical practice. Stimulating a heart transplant patients spontaneous expression about what they are experiencing and granting them the actual status of the main character in their own story is important to their care.
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Background: Chagas` disease is the illness caused by the protozoan Trypanosoma cruzi and it is still endemic in Latin America. Heart transplantation is a therapeutic option for patients with end-stage Chagas` cardiomyopathy. Nevertheless, reactivation may occur after transplantation, leading to higher morbidity and graft dysfunction. This study aimed to identify risk factors for Chagas` disease reactivation episodes. Methods: This investigation is a retrospective cohort study of all Chagas` disease heart transplant recipients from September 1985 through September 2004. Clinical, microbiologic and histopathologic data were reviewed. Statistical analysis was performed with SPSS (version 13) software. Results: Sixty-four (21.9%) patients with chronic Chagas` disease underwent heart transplantation during the study period. Seventeen patients (26.5%) had at least one episode of Chagas` disease reactivation, and univariate analysis identified number of rejection episodes (p = 0.013) and development of neoplasms (p = 0.040) as factors associated with Chagas` disease reactivation episodes. Multivariate analysis showed that number of rejection episodes (hazard ratio = 1.31; 95% confidence interval [CI]: 1.06 to 1.62; p = 0.011), neoplasms (hazard ratio = 5.07; 95% CI: 1.49 to 17.20; p = 0.009) and use of mycophenolate mofetil (hazard ratio = 3.14; 95% CI: 1.00 to 9.84; p = 0.049) are independent determinants for reactivation after transplantation. Age (p = 0.88), male gender (p = 0.15), presence of rejection (p = 0.17), cytomegalovirus infection (p = 0.79) and mortality after hospital discharge (p = 0.15) showed no statistically significant difference. Conclusions: Our data suggest that events resulting in greater immunosuppression status contribute to Chagas` disease reactivation episodes after heart transplantation and should alert physicians to make an early diagnosis and perform pre-emptive therapy. Although reactivation led to a high rate of morbidity, a low mortality risk was observed.
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Stromal cells from pediatric myelodysplastic syndromes (MDS) and acute myeloid leukemia (AML) associated with MDS(MDS-AML) present high expression of leukemia inhibitor factor (LIF). We demonstrated using mitogen-activated protein kinase ( MAPK) inhibitors that in stromal cells from pediatric MDS and MDS-AML, p38MAPK was critical in serum-induced secretion of LIF. The serum induction of phosphorylated p38MAPK form was observed only in stromal cells from healthy children, whereas in MDS and MDS-AML basal levels were maintained suggesting constitutive p38MAPK activation. Our study suggested the possible importance in pediatric MDS of p38MAPK signaling pathway which may be a future therapeutic target. (C) 2009 Elsevier Ltd. All rights reserved.
Resumo:
The taxane docetaxel is currently the most effective chemotherapeutic drug for the treatment of advanced breast cancer. However, a considerable proportion of breast cancer patients do not respond positively to docetaxel. The mechanisms of docetaxel resistance are poorly understood. Overexpression of ERBB2 occurs in 15-30% of breast tumors and is associated with chemoresistance to a variety of anticancer drugs. In the present study, we sought to identify genes involved in ERBB2-mediated chemoresistance to docetaxel. We generated SAGE libraries from two human mammary cell lines expressing basal (HB4a) and high (C5.2) levels of ERBB2 before and after intensive exposure to docetaxel and identified potential ERBB2 target genes implicated in a variety of cellular processes including cell proliferation, cell adhesion, apoptosis and cytoskeleton organization. Comparison of the transcriptome of the cell lines before and after docetaxel exposure revealed substantially different expression patterns. Twenty-one differentially expressed genes between HB4a and C5.2 cell lines, before and after docetaxel treatment, were further analyzed by qPCR. The alterations in the expression patterns in HB4a and C5.2 cell lines in response to docetaxel treatment observed by SAGE analysis were confirmed by qPCR for the majority of the genes analyzed. Our study provides a comprehensive view of the expression changes induced in two human mammary cells expressing different levels of ERBB2 in response to docetaxel that could contribute to the elucidation of the mechanisms involved in ERBB2-mediated chemoresistance in breast cancer.
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1. Evidence for a 'putative beta(4)-adrenoceptor' originated over 20 years ago when cardiostimulant effects were observed to nonconventional partial agonists, These agonists were originally described as beta(1)- and beta(2)-adrenoceptor antagonists; however, they cause cardiostimulant effects at much higher concentrations than those required to block beta(1)- and beta(2)-adrenoceptors. Cardiostimulant effects of non-conventional partial agonists have been observed in mouse, rat, guinea-pig, cat, ferret and human heart tissues, 2. The receptor is expressed in several heart regions, including the sinoatrial node, atrium and ventricle, 3. The receptor is resistant to blockade by most antagonists that possess high affinity for beta(1)- and beta(2)- adrenoceptors, but is blocked with moderate affinity by (-)-bupranolol and CGP 20712A. 4. The receptor is pharmacologically distinct from the beta(3)-adrenoceptor. Micromolar concentrations of beta(3)-adrenoceptor agonists have no agonist or blocking activity, The receptor is also resistant to blockade by a beta(3)-adrenoceptor-selective antagonist. 5. The receptor mediates increases in cAMP levels and cAMP-dependent protein kinase (PK) A activity in cardiac tissues. Phosphodiesterase inhibition potentiates the positive chronotropic and inotropic effects of non-conventional partial agonists. 6. The receptor mediates hastening of atrial and ventricular relaxation, which is consistent with involvement of a cAMP-dependent pathway. 7. The non-conventional partial agonist (-)-[H-3]-CGP 12177A labels the cardiac putative beta(4)-adrenoceptor, Non-conventional partial agonists compete for binding with affinities that are closely similar to their agonist potencies, Catecholamines compete for binding in a stereoselective manner with a rank order of affinity of (-)-R0363 > (-)-isoprenaline > (-)-noradrenaline greater than or equal to (-)-adrenaline much greater than (-)-isoprenaline, suggesting that catecholamines can interact with the receptor. 8. The putative beta(4)-adrenoceptor appears to be coupled to the G(s)-adenylyl cyclase system, which could serve as a guide to its future cloning, Activation of the receptor may plausibly improve diastolic function but could also mediate arrhythmias.
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In previous studies, we determined that beta 1 integrins from human colon tumors have elevated levels of alpha 2-6 sialylation, a modification added by beta-galactosamide alpha-2,6-sialyltranferase I (ST6Gal-I). Intriguingly, the beta 1 integrin is thought to be a ligand for galectin-3 (gal-3), a tumor-associated lectin. The effects of gal-3 are complex; intracellular forms typically protect cells against apoptosis through carbohydrate-independent mechanisms, whereas secreted forms bind to cell surface oligosaccharides and induce apoptosis. In the current study, we tested whether alpha 2-6 sialylation of the beta 1 integrin modulates binding to extracellular gal-3. Herein we report that SW48 colonocytes lacking alpha 2-6 sialylation exhibit beta 1 integrin-dependent binding to gal-3-coated tissue culture plates; however, binding is attenuated upon forced expression of ST6Gal-I. Removal of alpha 2-6 sialic acids from ST6Gal-I expressors by neuraminidase treatment restores gal-3 binding. Additionally, using a blot overlay approach, we determined that gal-3 binds directly and preferentially to unsialylated, as compared with alpha 2-6-sialylated, beta 1 integrins. To understand the physiologic consequences of gal-3 binding, cells were treated with gal-3 and monitored for apoptosis. Galectin-3 was found to induce apoptosis in parental SW48 colonocytes ( unsialylated), whereas ST6Gal-I expressors were protected. Importantly, gal-3-induced apoptosis was inhibited by function blocking antibodies against the beta 1 subunit, suggesting that beta 1 integrins are critical transducers of gal-3-mediated effects on cell survival. Collectively, our results suggest that the coordinate up-regulation of gal-3 and ST6Gal-I, a feature that is characteristic of colon carcinoma, may confer tumor cells with a selective advantage by providing a mechanism for blockade of the pro-apoptotic effects of secreted gal-3.
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Vitamin D (VD), is a steroid hormone with multiple functions in the central nervous system (CNS), producing numerous physiological effects mediated by its receptor (VDR). Clinical and experimental studies have shown a link between VD dysfunction and epilepsy. Along these lines, the purpose of our work was to analyze the relative expression of VDR mRNA in the hippocampal formation of rats during the three periods of pilocarpine-induced epilepsy. Male Wistar rats were divided into five groups: (1) control group; rats that received saline 0.9%, i.p. and were killed 7 days after its administration (CTRL, n = 8), (2) SE group; rats that received pilocarpine and were killed 4 h after SE (SE, n = 8), (3) Silent group-7 days; rats that received pilocarpine and were killed 7 days after SE (SIL 7d, n = 8), (4) Silent group-14 days; rats that received pilocarpine and were killed 14 days after SE (SIL 14d, n = 8), (5) Chronic group; rats that received pilocarpine and were killed 60 days after the first spontaneous seizure, (chronic, n = 8). The relative expression of VDR mRNA was determined by real-time PCR. Our results showed an increase of the relative expression of VDR mRNA in the SIL 7 days, SIL 14 days and Chronic groups, respectively (0.060 +/- 0.024; 0.052 +/- 0.035; 0.085 +/- 0.055) when compared with the CTRL and SE groups (0.019 +/- 0.017; 0.019 +/- 0.025). These data suggest the VDR as a possible candidate participating in the epileptogenesis process of the pilocarpine model of epilepsy. (C) 2008 Elsevier Inc. All rights reserved.
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Malignant melanoma is one of the most lethal cancers. Nowadays, several anti-melanoma therapies have been employed. However, the poor prognosis and/or the increased toxicity of those treatments clearly demonstrate the requirement of searching for new drugs or novel combined chemotherapeutic protocols, contemplating both effectiveness and low toxicity. Guanosine (Guo) has been used in combination with acriflavina to potentiate the latter`s antitumor activity, through still unknown mechanisms. Here, we show that Guo induces B16F10 melanoma cell differentiation, attested by growth arrest, dendrite-like outgrowth and increased melanogenesis, and also reduced motility. A sustained ERK 1/2 phosphorylation was observed after Guo treatment and ERK inhibition led to blockage of dendritogenesis. Intracellular cyclic AMP was not involved in ERK activation, since its levels remained unchanged. Protein kinase C (PKC), in contrast to phospholipase C (PLC), inhibition completely prevented ERK activation. While the classical melanoma differentiation agent forskolin activates cAMP-PKA-Raf-MEK-ERK pathway in B16F10 cells, here we suggest that a cAMP-independent, PKC-ERK axis is involved in Guo-induced B16F10 differentiation. Altogether, our results show that Guo acts as a differentiating agent, with cytostatic rather than cytotoxic properties, leading to a decreased melanoma malignancy. Thus, we propose that Guo may be envisaged in combination with lower doses of conventional anti-melanoma drugs, in an attempt to prevent or diminish their adverse effects. (c) 2008 Elsevier Ireland Ltd. All rights reserved.
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A case of hair depigmentation induced by chloroquine diphosphate subacute overdosage in an 11-year-old patient with dermatomyositis is presented. Normal coloured hair growth occurred after normalisation of chloroquine dosage. A discussion on possible pathomechanisms of this phenomenon is made based on experimental data and previously reported patients with the same condition. Lupus (2009) 18, 264-266.
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Linear IgA disease is a rare autoimmune subepidermal bullous disorder characterized by linear IgA deposits at the epidermal basement membrane zone. According to the literature, in patients who have linear IgA disease and become pregnant, the disease tends to improve. We report a case of linear IgA disease induced by pregnancy, successfully treated with dapsone and prednisone with no adverse effects observed in the patient and her newborns.
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We aimed to investigate the vascular effects of hyperhomocysteinemia (HHcy) on carotid arteries from young and adult rats. With this purpose young and adult rats received a solution of DL-homocysteine-thiolactone (1 g/kg body weight/day) in the drinking water for 7, 14 and 28 days. Increase on plasma homocysteine occurred in young and adult rats treated with DL-homocysteine-thiolactone in all periods. Vascular reactivity experiments using standard muscle bath procedures showed that HHcy enhanced the contractile response of endothelium-intact, carotid rings to phenylephrine in both young and adult rats. However, in young rats, the increased phenylephrine-induced contraction was observed after hyperhomocysteinemia for 14 and 28 days, whereas in adult rats this response was already apparent after 7 day treatment. HHcy impaired acetylcholine-induced relaxation in arteries from adult but not young rats. The contraction induced by phenylephrine in carotid arteries in the presence of Y-27632 was reversed to control values in arteries from young but not adult rats with hyperhomocysteinemia. HHcy did not alter the contraction induced by CaCl(2) in carotid arteries from young rats, but enhanced CaCl(2)-induced contraction in the arteries from adult rats. HHcy increased the basal levels of superoxide anion in arteries from both groups. Finally, HHcy decreased the basal levels of nitrite in arteries from adult but not young rats. The major new finding of the present work is that arteries from young rats are more resistant to vascular changes evoked by HHcy than arteries from adult rats. Also, we verified that the enhanced vascular response to phenylephrine observed in carotid arteries of DL-homocysteine thiolactone-treated rats is mediated by different mechanisms in young and adult rats. (C) 2010 Published by Elsevier Inc.
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The present study aimed to evaluate the role of nitric oxide (NO) on hyperpnea-induced bronchoconstriction (HIB) and airway microvascular hyperpermeability (AMP). Sixty-four guinea pigs were anesthetized, tracheotonnized, cannulated, and connected to animal ventilator to obtain pulmonary baseline respiratory system resistance (Rrs). Animals were then submitted to 5 minutes hyperpnea and Rrs was evaluated during 15 minutes after hyperpnea. AMP was evaluated by Evans blue dye (25 mg/kg) extravasation in airway tissues. Constitutive and inductible NO was evaluated by pretreating animals with N(G)-nitro-1-arginine methyl ester (I-NAME) (50 mg/kg), aminoguadinine (AG) (50 mg/kg), and I-arginine (100 mg/kg) and exhaled NO (NOex) was evaluated before and after drug administration and hyperpnea. The results show that I-NAME potentiated (57%) HIB and this effect was totally reversed by I-arginine pretreatment, whereas AG did not have effect on HIB. I-NAME decreased basal AMP (48%), but neither I-NAME nor AG had any effect on hyperpnea-induced AMP. NOex levels were decreased by 50% with I-NAME, effect that was reversed by I-arginine treatment. These results suggest that constitutive but not inducible NO could have a bronchoprotective effect on HIB in guinea pigs. The authors also observed that neither constitutive nor inducible NO seems to have any effect on hyperpnea-induced AMP.
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Matrix metalloproteinases (MMPs) are crucial to the development and maintenance of healthy tissue and are mainly involved in extracellular matrix (ECM) remodeling of skeletal muscle. This study evaluated the effects of chronic allergic airway inflammation (CAAI), induced by ovalbumin, and aerobic training in the MMPs activity in mouse diaphragm muscle. Thirty mice were divided into 6 groups: 1) control; 2) ovalbumin; 3) treadmill trained at 50% of maximum speed; 4) ovalbumin and trained at 50%; 5) trained at 75%; 6) ovalbumin and trained at 75%. CAAI did not after MMPs activities in diaphragm muscle. Nevertheless, both treadmill aerobic trainings, associated with CAAI increased the MMP-2 and -1 activities. Furthermore, MMP-9 was not detected in any group. Together, these findings suggest an ECM remodeling in diaphragm muscle of asthmatic mice submitted to physical training. This result may be useful for a better understanding of functional significance of changes in the MMPs activity in response to physical training in asthma.
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We compared the aldosterone-producing potency of the angiotensin II-sensitive wild-type aldosterone synthase genes and the ACTH-sensitive hybrid 11 beta-hydroxylase/aldosterone synthase gene by examining aldosterone, PRA, and cortisol day-curves (2-hourly levels over 24 h) in patients with familial hyperaldosteronism type I, before and during long-term (0.8-13.5 yr) glucocorticoid treatment. In 8 untreated patients, PRA levels were usually suppressed, and aldosterone correlated strongly with cortisol (r = 0.69-0.99). Fourteen studies were performed on 10 patients receiving glucocorticoid treatment that corrected hypertension, hypokalemia, and PRA suppression in all. ACTH was markedly and continuously suppressed in 6 studies, 3 of which demonstrated strong correlations between aldosterone and PRA (r = 0.77-0.92), ACTH was only partially suppressed in the remaining 8 studies; aldosterone correlated strongly: 1) with cortisol alone in 5 (r = 0.71-0.98); 2) with cortisol (r = 0.90) and PRA (r = 0.74) in one; 3) with PRA only in one (r = 0.80); and 4) with neither PRA nor cortisol in one. Unless ACTH is markedly and continuously suppressed, aldosterone is more responsive to ACTH than to renin/angiotensin II, despite the latter being unsuppressed. This is consistent with the hybrid gene being more powerfully expressed than the wild-type aldosterone synthase genes in familial hyperaldosteronism type I.
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Background The clinical view of case fatality (CF) from acute myocardial infarction (AMI) in those reaching the hospital alive is different from the population view. Registration of both hospitalized AMI cases and out-of-hospital coronary heart disease (CHD) deaths in the WHO MONICA Project allows both views to be reconciled. The WHO MONICA Project provides the largest data set worldwide to explore the relationship between CHD CF and age, sex, coronary event rate, and first versus recurrent event. Methods and Results All 79 669 events of definite AMI or possible coronary death, occurring from 1985 to 90 among 5 725 762 people, 35 to 64 years of age, in 29 MONICA populations are the basis for CF calculations. Age-adjusted CF (percentage of CHD events that were fatal) was calculated across populations, stratified for different time periods, and related to age, sex, and CHD event rate. Median 28-day population CF was 49% (range, 35% to 60%) in men and 51% (range, 34% to 70%) in women and was particularly higher in women than men in populations in which CHD event rates were low. Median 28-day CF for hospitalized events was much lower: in men 22% (range, 15% to 36%) and in women 27% (range, 19% to 46%). Among hospitalized events CF was twice as high for recurrent as for first events. Conclusions Overall 28-day CF is halved for hospitalized events compared with all events and again nearly halved for hospitalized 24-hour survivors. Because approximately two thirds of 28-day CHD deaths in men and women occurred before reaching the hospital, opportunities for reducing CF through improved care in the acute event are limited. Major emphasis should be on primary and secondary prevention.