2,168 research outputs found

    The role of abscisic acid and water relations in drought responses of subterranean clover

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    The role of water relations and abscisic acid (ABA) in the responses to drought were studied in a mediterranean forage crop, Trifolium subterraneum L. under field conditions. soil and plant water status, leaf gas exchange parameters, and xylem sap ABA content were determined at different times during a long-term soil drying episode in irrigated and droughted plants. The diurnal time-courses of these parameters were also measured at the end of a drought period. In response to soil drying stomatal conductance (g) was reduced early to 50% that of irrigated plants before any substantial change in water potential was detected. A close logarithmic regression between photosynthesis rate (A) and g was present. For the first weeks of drought the decline in A was less pronounced than in g, thus increasing water use efficiency. Stomatal conductance during diurnal time-courses showed no consistent relationships with respect to either ABA or leaf water potential. throughout the experimental period dependence of g on leaf water status was evident from the tight correlation (r(2) = 0.88, P < 0.01) achieved between stomatal conductance and midday water potential, but the correlation was also high when comparing g with respect to ABA content in xylem sap (r(2) = 0.83, P < 0.001). However, the stomata from drought acclimated plants were apparently more sensitive to xylem ABA content. For similar xylem ABA concentrations stomatal conductance was significantly higher in irrigated than in water-stressed plants.info:eu-repo/semantics/publishedVersio

    Heart Transplantation in Patients Older than 65 Years: Worthwhile or Wastage of Organs?

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    BACKGROUND: Patients older than 65 years have traditionally not been considered candidates for heart transplantation. However, recent studies have shown similar survival. We evaluated immediate and medium-term results in patients older than 65 years compared with younger patients. METHODS: From November 2003 to December 2013, 258 patients underwent transplantation. Children and patients with other organ transplantations were excluded from this study. Recipients were divided into two groups: 45 patients (18%) aged 65 years and older (Group A) and 203 patients (81%) younger than 65 years (Group B). RESULTS: Patients differed in age (67.0 ± 2.2 vs. 51.5 ± 9.7 years), but gender (male 77.8 vs. 77.3%; p = 0.949) was similar. Patients in Group A had more cardiovascular risk factors and ischemic cardiomyopathy (60 vs. 33.5%; p < 0.001). Donors to Group A were older (38.5 ± 11.3 vs. 34.0 ± 11.0 years; p = 0.014). Hospital mortality was 0 vs. 5.9% (p = 0.095) and 1- and 5-year survival were 88.8 ± 4.7 versus 86.8 ± 2.4% and 81.5 ± 5.9 versus 77.2 ± 3.2%, respectively. Mean follow-up was 3.8 ± 2.7 versus 4.5 ± 3.1 years. Incidence of cellular/humoral rejection was similar, but incidence of cardiac allograft vasculopathy was higher (15.6 vs. 7.4%; p = 0.081). Incidence of diabetes de novo was similar (p = 0.632), but older patients had more serious infections in the 1st year (p = 0.018). CONCLUSION: Heart transplantation in selected older patients can be performed with survival similar to younger patients, hence should not be restricted arbitrarily. Incidence of infections, graft vascular disease, and malignancies can be reduced with a more personalized approach to immunosuppression. Allocation of donors to these patients does not appear to reduce the possibility of transplanting younger patients

    Mercapturate Pathway in the Tubulocentric Perspective of Diabetic Kidney Disease

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    BACKGROUND: The recent growing evidence that the proximal tubule underlies the early pathogenesis of diabetic kidney disease (DKD) is unveiling novel and promising perspectives. This pathophysiological concept links tubulointerstitial oxidative stress, inflammation, hypoxia, and fibrosis with the progression of DKD. In this new angle for DKD, the prevailing molecular mechanisms on proximal tubular cells emerge as an innovative opportunity for prevention and management of DKD as well as to improve diabetic dysmetabolism. SUMMARY: The mercapturate pathway (MAP) is a classical metabolic detoxification route for xenobiotics that is emerging as an integrative circuitry detrimental to resolve tubular inflammation caused by endogenous electrophilic species. Herein we review why and how it might underlie DKD. Key Messages: MAP is a hallmark of proximal tubular cell function, and cysteine-S-conjugates might represent targets for early intervention in DKD. Moreover, the biomonitoring of urinary mercapturates from metabolic inflammation products might be relevant for the implementation of preventive/management strategies in DKD.info:eu-repo/semantics/publishedVersio

    Aortic root enlargement does not increase the surgical risk and short-term patient outcome

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    Objective: To analyze the short-term outcome of aortic root enlargement (ARE) using death and adverse events as end points. Methods: From January 1999 through December 2009, 3339 patients were subjected to aortic valve replacement (AVR). A total of 678 were considered to have small aortic roots (SARs) in which an aortic prosthesis size 21mm or smaller was implanted. ARE using a bovine pericardial patch was performed in another 218 patients, who constitute the study population. This comprised 174 females (79.8%); the mean age was 69.4±13.4 years (8-87, median 74 years), the body surface area (BSA) was 1.59±0.15m(2) and the body mass index (BMI) 25.77±3.16kgm(-2), and 192 (88.5%) were in New York Heart Association (NYHA) II-III. Preoperative echocardiography revealed significant left ventricular (LV) dysfunction in 17 patients (8%), a mean aortic valve area of 0.57±0.27cm(2), and a mean gradient of 62.51±21.25mmHg. A septal myectomy was performed in 129 subjects (59.2%), and other associated procedures, mostly coronary artery bypass grafting (CABG), in 60 (27.5%). Bioprostheses were implanted in 161 patients (73.9%). The mean valve size was 21.9±1.0 (21-25). The mean extracorporeal circulation (ECC) and aortic clamping times were 82.8±19.8min and 56.8±12.5min, respectively. Results: Hospital mortality was 0.9% (n=2) for ARE as compared with 0.6% (n=4) for the SAR group (p=0.8). Inotropic support was required in only 13 (5.9%) patients and the first 24-h chest drainage was 336.2±202ml. Other complications included pacemaker implantation (7.8%), acute renal failure (10.6%), respiratory (4.1%), and CVA/transient ischemic attack (CVA/TIA) (3.2%). Postoperative echocardiographic evaluation showed a significant decrease in peak and mean aortic gradients (23.7±9.5 and 14±6.2mmHg, respectively, p<0.0001). The mean indexed effective orifice area (iEOA) was 0.92±0.01cm(2)m(-2) (vs 0.84±0.07cm(2)m(-2), in SAR, p<0.0001). Only 11% of patients (n=24) with ARE exhibited moderate patient-prosthesis mismatch (PPM) and none had severe PPM. Mean hospital stay was 9.7±9.29 days (median 7 days). Conclusions: With the growing number of patients with degenerative aortic valve pathology, mainly an older population, sometimes with calcified and fragile aortic wall, the issue of dealing with an SAR poses the dilemma of whether to implant a smaller prosthesis and admit some degree of PPM, or to enlarge the aortic root. This study demonstrates that the latter can be done in a safe and reproducible manner

    Long-term follow-up of asymptomatic or mildly symptomatic patients with severe degenerative mitral regurgitation and preserved left ventricular function

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    OBJECTIVES: The timing for mitral valve surgery in asymptomatic patients with severe mitral regurgitation and preserved left ventricular function remains controversial. We analyzed the immediate and long-term outcomes of these patients after surgery. METHODS: From January 1992 to December 2012, 382 consecutive patients with severe chronic degenerative mitral regurgitation, with no or mild symptoms, and preserved left ventricular function (ejection fraction ≥ 60%) were submitted to surgery and followed for up to 22 years (3209 patient-years). Patients with associated surgeries, other than tricuspid valve repair, were excluded. Cox proportional-hazard survival analysis was performed to determine predictors of late mortality and mitral reoperation. Subgroup analysis involved patients with atrial fibrillation or pulmonary hypertension. RESULTS: Mitral valvuloplasty was performed in 98.2% of cases. Thirty-day mortality was 0.8%. Overall survival at 5, 10, and 20 years was 96.3% ± 1.0%, 89.7% ± 2.0%, and 72.4% ± 5.8%, respectively, and similar to the expected age- and gender-adjusted general population. Patients with atrial fibrillation/pulmonary hypertension had a 2-fold risk of late mortality compared with the remaining patients (hazard ratio, 2.54; 95% confidence interval, 1.17-4.80; P = .018). Benefit was age-dependent only in younger patients (<65 years; P = .016). Patients with atrial fibrillation/pulmonary hypertension (hazard ratio, 4.20, confidence interval, 1.10-11.20; P = .037) and patients with chordal shortening were at increased risk for reoperation, whereas patients with P2 prolapse (hazard ratio, 0.06; confidence interval, 0.008-0.51; P = .037) and patients with myxomatous valves (hazard ratio, 0.072; confidence interval, 0.008-0.624; P = .017) were at decreased risk. CONCLUSIONS: Mitral valve repair can be achieved in the majority of patients with low mortality (<1%) and excellent long-term survival. Patients with atrial fibrillation/pulmonary hypertension had compromised long-term survival, particularly younger patients (aged <65 years), and are at increased risk of mitral reoperation.info:eu-repo/semantics/publishedVersio

    Assessment of DNA and mtDNA Degradation in Sperm Cells Collected by Laser Micro-dissection

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    Sexual assault samples are among the most frequently analyzed in a forensic laboratory. These accounts for almost half of all samples processed routinely and a large portion of these cases remain unsolved. These samples often pose problems to traditional analytic methods of identification because they consist most frequently of cell mixtures from at least two contributors: the victim (usually female) and the perpetrator (usually male). In this study we prepared simulated sexual assault samples and conducted amplification and DNA genotyping from sperm cells collected with laser microdissection at different time intervals to assess the DNA degradation at those intervals. Furthermore, we then investigated the possibility of recovering mtDNA from the collected sperm cells, particularly in cases where autosomal DNA was not suitably amplified. With this work we determined that it becomes possible to extend the timeframe for performing an analysis, by researching other sources of DNA, namely mtDNA.info:eu-repo/semantics/publishedVersio

    Contraceptive Choices Pre and Post Pregnancy in Adolescence

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    STUDY OBJECTIVE: The main aim of this study is to evaluate the impact of adolescent pregnancy in the future contraceptive choices. A secondary aim is to verify whether these choices differ from those made after an abortion. DESIGN: Retrospective study. SETTING:Adolescent Unit of a tertiary care center. PARTICIPANTS:212 pregnant teenagers. INTERVENTIONS: Medical records review. MAIN OUTCOME MEASURES:Intended pregnancy rate and contraceptive methods used before and after pregnancy. For contraceptive choices after pregnancy we considered: Group 1 - teenagers who continued their pregnancy to delivery (n = 106) and Group 2 - the same number of adolescents who chose to terminate their pregnancy. RESULTS: The intended pregnancy rate was 14.2%. Prior to a pregnancy continued to delivery, the most widely used contraceptive method was the male condom (50.9%), followed by oral combined contraceptives (28.3%); 18.9% of adolescents were not using any contraceptive method. After pregnancy, contraceptive implant was chosen by 70.8% of subjects (P < .001) and the oral combined contraceptives remained the second most frequent option (17.9%, P = .058). Comparing these results with Group 2, we found that the outcome of the pregnancy was the main factor in the choices that were made. Thus, after a pregnancy continued to delivery, adolescents prefer the use of LARC [78.4% vs 40.5%, OR: 5,958 - 95% (2.914-12.181), P < .001)], especially contraceptive implants [70.8% vs 38.7%, OR: 4.371 - 95% (2.224-8.591), P < .001], to oral combined contraceptives [17.9% vs 57.5%, OR: 0.118 - 95% CI (0.054-0.258), P < .001]. CONCLUSION:Adolescent pregnancy and its outcome constitute a factor of change in future contraceptive choice

    Maternal smoking: a life course blood pressure determinant?

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    Introduction: Exposure to maternal smoking early in life may affect blood pressure (BP) control mechanisms. We examined the association between maternal smoking (before conception, during pregnancy, and 4 years after delivery) and BP in preschool children. Methods: We evaluated 4295 of Generation XXI children, recruited at birth in 2005–2006 and reevaluated at the age of 4. At birth, information was collected by face-to-face interview and additionally abstracted from clinical records. At 4-year follow-up, interviews were performed and children’s BP measured. Linear regression models were fitted to estimate the association between maternal smoking and children’s BP. Results: Children of smoking mothers presented significantly higher BP levels. After adjustment for maternal education, gestational hypertensive disorders, and child’s body mass index, children exposed during pregnancy to maternal smoking presented a higher systolic BP (SBP) z-score (β = 0.08, 95% confidence interval [CI] 0.04 to 0.14). In crude models, maternal smoking was associated with higher SBP z-score at every assessed period. However, after adjustment, an attenuation of the association estimates occurred (β = 0.08, 95% CI 0.03 to 0.13 before conception; β = 0.07, 95%CI 0.02 to 0.12; β = 0.04, 95%CI −0.02 to 0.10; and β = 0.06, 95%CI 0.00 to 0.13 for the first, second, and third pregnancy trimesters, respectively; and β = 0.07, 95%CI 0.02 to 0.12 for current maternal smoking). No significant association was observed for diastolic BP z-score levels. Conclusion: Maternal smoking before, during, and after pregnancy was independently associated with systolic BP z-score in preschool children. This study provides additional evidence to the public health relevance of maternal smoking cessation programs if early cardiovascular health of children is envisaged. Implications: Using observational longitudinal data from the birth cohort Generation XXI, this study showed that exposure to maternal smoking—before pregnancy, during pregnancy, and 4 years after delivery—was associated with a systolic BP-raising effect in children at the age of 4. The findings of this study add an important insight into the need to support maternal smoke-free environments in order to provide long-term cardiovascular benefit, starting as early as possible in life.Generation XXI has been funded by the Operational Health Programme XXI Health, Community support framework III (co-funded by Feder), Administração Regional de Saúde do Norte, Fundação Calouste Gulbenkian and Fundação para a Ciência e Tecnologia (SFRH/BSAB/113778/2015; PD/BD/105824/2014; PD/BD/105827/2014; F-COMP-01-0124-FEDER-011008; FCT—PTDC/SAU-ESA/105033/2008). Also, the Portuguese Foundation for Science and Technology funds the Epidemiology Research Unit of the Institute of Public Health of the University of Porto (UID/DTP/04750/2013). This article is a result of the project DOCnet (NORTE-01-0145-FEDER-000003), supported by Norte Portugal Regional Operational Programme (NORTE 2020), under the PORTUGAL 2020 Partnership Agreement, through the European Regional Development Fund (ERDF)

    A decade of cardiac transplantation in Coimbra: the value of experience

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    INTRODUCTION AND OBJECTIVES: To analyze the experience gained in 10 years of the heart transplantation program of the University Hospital of Coimbra. METHODS: Between November 2003 and December 2013, 258 patients with a mean age of 53.0±12.7 years (3-72 years) and predominantly male (78%) were transplanted. Over a third of patients had ischemic (37.2%) and 36.4% idiopathic cardiomyopathy. The mean age of donors was 34.4±1.3 years and 195 were male (76%), with gender difference between donor and recipient in 32% of cases and ABO disparity (non-identical groups but compatible) in 18%. Harvest was distant in 59% of cases. In all cases total heart transplantation with bicaval anastomoses, modified at this center, was used. Mean ischemia time was 89.7±35.4 minutes. All patients received induction therapy. RESULTS: Early mortality was 4.7% (12 patients) from graft failure and stroke in five patients each, and hyperacute rejection in two. Thirteen patients (5%) required prolonged ventilation, 25 (11.8%) required inotropic support for more than 48 hours, and seven required pacemaker implantation. Mean hospital stay was 15.8±15.3 days (median 12 days). Ninety percent of patients were maintained on triple immunosuppressive therapy including cyclosporine, the remainder receiving tacrolimus. In 23 patients it was necessary to change the immunosuppression protocol due to renal and/or neoplastic complications and humoral rejection. All but two patients have been followed in the Surgical Center. Fifty patients (19.4%) subsequently died from infection (18), cancer (10), vascular (eight), neuropsychiatric (four), cardiac (two) or other causes (eight). Forty-six patients (17.8%) had episodes of cellular rejection (>2 R on the ISHLT classification), eight had humoral rejection (3.1%), and 22 have evidence of graft vascular disease (8.5%). Actuarial survival at 1, 5, and 8 years was 87±2%, 78±3% and 69±4%, respectively. CONCLUSION: This 10-year series yielded results equivalent or superior to those of centers with wider and longer experience, and have progressively improved following the introduction of changes prompted by experience. This program has made it possible to raise and maintain the rate of heart transplantation to values above the European average

    Advanced tools and techniques to add value to soil stabilization practice

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    The aim of this paper is to demonstrate the advanced tools and techniques used for adding value to the soil stabilization practice. The tools presented involve advanced laboratory tests and modeling using codes and soft computing to evaluate the mechanical behavior of stabilized soils with cement, ranging from short-term to long-term behavior. More precisely, these tools are able to: 1. Predict the mechanical behavior of the stabilized soils over time from data obtained in the early ages saving time in laboratory tests; 2. Predict the mechanical behavior of the stabilized soils over time based on basic parameters of soil type and binder using historical accurate data, avoiding mechanical laboratory tests. 3. Incorporate the serviceability limit state concept in a novel proposal to estimate the design modulus in function of the uniaxial compressive strength and the strain level, making more economic and sustainable geotechnical solutions.This work was supported by FCT—‘‘Fundação para a Ciência e a Tecnologia’’, within ISISE, project UID/ECI/04029/2013 and through the post doctoral Grant fellowship with reference SFRH/BPD/94792/2013. This work was also partly financed by FEDER funds through the Competitivity Factors Operational Programme—COMPETE and by national funds through FCT within the scope of the project POCI-01-0145-FEDER-007633.info:eu-repo/semantics/publishedVersio
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