61 research outputs found

    Proton NMR studies of the electronic structure of ZrH/sub x/

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    The proton spin lattice relaxation times and Knight shifts were measured in f.c.c. (delta-phase) and f.c.t. (epsilon-phase) ZrH/sub x/ for 1.5 or = to x or = to 2.0. Both parameters indicate that N(E/sub F/) is very dependent upon hydrogen content with a maximum occurring at ZrH1 83. This behavior is ascribed to modifications in N(E/sub F/) through a fcc/fct distortion in ZrH/sub x/ associated with a Jahn-Teller effect

    Differential effect of vinorelbine versus paclitaxel on ERK2 kinase activity during apoptosis in MCF-7 cells

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    The effects of vinorelbine and paclitaxel on the activity of extracellular signal-regulated protein kinase2 (ERK2), a member of MAP kinase, and its role in the induction of bcl-2 phosphorylation and apoptosis were evaluated in MCF-7 cells. We demonstrated that ERK2 was activated rapidly by vinorelbine, and was inhibited by either paclitaxel or estramustine. A 3-fold increase of ERK2 kinase activity was observed within 30 min when MCF-7 cells were treated with 0.1 μM vinorelbine. In contrast, the same treatment with paclitaxel resulted in a significant decrease of ERK2 kinase activity. We also demonstrated that elevated bcl-2 phosphorylation induced by vinorelbine is paralleled by decrease of a complex formation between bcl-2 and bax, cleavage of poly (ADP) ribose polymerase (PARP) protein, activation of caspase-7, and apoptosis. The levels of bcl-2 phosphorylation, bax, and PARP were not significantly affected by 2′-amino-3′-methoxyflavone (PD 98059), an ERK kinase specific inhibitor. Thus, our data suggest that the apoptosis induced by vinorelbine in MCF-7 cells is mediated through the bcl-2 phosphorylation/bax/caspases pathways, and that activation of ERK2 by vinorelbine does not directly lead to the drug-mediated apoptosis. Since decrease of PARP occurred quickly following the treatment of MCF-7 cells with either 0.1 μM of vinorelbine or paclitaxel, this protein may serve as an early indicator of apoptosis induced not only by DNA damaging agents, but also by antimicrotubule drugs.   http://www.bjcancer.com © 2001 Cancer Research Campaig

    An overview of the utilisation of microalgae biomass derived from nutrient recycling of wet market wastewater and slaughterhouse wastewater

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    Microalgae have high nutritional values for aquatic organisms compared to fish meal, because microalgae cells are rich in proteins, lipids, and carbohydrates. However, the high cost for the commercial production of microalgae biomass using fresh water or artificial media limits its use as fish feed. Few studies have investigated the potential of wet market wastewater and slaughterhouse wastewater for the production of microalgae biomass. Hence, this study aims to highlight the potential of these types of wastewater as an alternative superior medium for microalgae biomass as they contain high levels of nutrients required for microalgae growth. This paper focuses on the benefits of microalgae biomass produced during the phycore-mediation of wet market wastewater and slaughterhouse wastewater as fish feed. The extraction techniques for lipids and proteins as well as the studies conducted on the use of microalgae biomass as fish feed were reviewed. The results showed that microalgae biomass can be used as fish feed due to feed utilisation efficiency, physiological activity, increased resistance for several diseases, improved stress response, and improved protein retention

    Frequency of left ventricular hypertrophy in non-valvular atrial fibrillation

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    Left ventricular hypertrophy (LVH) is significantly related to adverse clinical outcomes in patients at high risk of cardiovascular events. In patients with atrial fibrillation (AF), data on LVH, that is, prevalence and determinants, are inconsistent mainly because of different definitions and heterogeneity of study populations. We determined echocardiographic-based LVH prevalence and clinical factors independently associated with its development in a prospective cohort of patients with non-valvular (NV) AF. From the "Atrial Fibrillation Registry for Ankle-brachial Index Prevalence Assessment: Collaborative Italian Study" (ARAPACIS) population, 1,184 patients with NVAF (mean age 72 \ub1 11 years; 56% men) with complete data to define LVH were selected. ARAPACIS is a multicenter, observational, prospective, longitudinal on-going study designed to estimate prevalence of peripheral artery disease in patients with NVAF. We found a high prevalence of LVH (52%) in patients with NVAF. Compared to those without LVH, patients with AF with LVH were older and had a higher prevalence of hypertension, diabetes, and previous myocardial infarction (MI). A higher prevalence of ankle-brachial index 640.90 was seen in patients with LVH (22 vs 17%, p = 0.0392). Patients with LVH were at significantly higher thromboembolic risk, with CHA2DS2-VASc 652 seen in 93% of LVH and in 73% of patients without LVH (p <0.05). Women with LVH had a higher prevalence of concentric hypertrophy than men (46% vs 29%, p = 0.0003). Logistic regression analysis demonstrated that female gender (odds ratio [OR] 2.80, p <0.0001), age (OR 1.03 per year, p <0.001), hypertension (OR 2.30, p <0.001), diabetes (OR 1.62, p = 0.004), and previous MI (OR 1.96, p = 0.001) were independently associated with LVH. In conclusion, patients with NVAF have a high prevalence of LVH, which is related to female gender, older age, hypertension, and previous MI. These patients are at high thromboembolic risk and deserve a holistic approach to cardiovascular prevention

    Prognostic model to predict postoperative acute kidney injury in patients undergoing major gastrointestinal surgery based on a national prospective observational cohort study.

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    Background: Acute illness, existing co-morbidities and surgical stress response can all contribute to postoperative acute kidney injury (AKI) in patients undergoing major gastrointestinal surgery. The aim of this study was prospectively to develop a pragmatic prognostic model to stratify patients according to risk of developing AKI after major gastrointestinal surgery. Methods: This prospective multicentre cohort study included consecutive adults undergoing elective or emergency gastrointestinal resection, liver resection or stoma reversal in 2-week blocks over a continuous 3-month period. The primary outcome was the rate of AKI within 7 days of surgery. Bootstrap stability was used to select clinically plausible risk factors into the model. Internal model validation was carried out by bootstrap validation. Results: A total of 4544 patients were included across 173 centres in the UK and Ireland. The overall rate of AKI was 14·2 per cent (646 of 4544) and the 30-day mortality rate was 1·8 per cent (84 of 4544). Stage 1 AKI was significantly associated with 30-day mortality (unadjusted odds ratio 7·61, 95 per cent c.i. 4·49 to 12·90; P < 0·001), with increasing odds of death with each AKI stage. Six variables were selected for inclusion in the prognostic model: age, sex, ASA grade, preoperative estimated glomerular filtration rate, planned open surgery and preoperative use of either an angiotensin-converting enzyme inhibitor or an angiotensin receptor blocker. Internal validation demonstrated good model discrimination (c-statistic 0·65). Discussion: Following major gastrointestinal surgery, AKI occurred in one in seven patients. This preoperative prognostic model identified patients at high risk of postoperative AKI. Validation in an independent data set is required to ensure generalizability

    Association between peri-operative angiotensin-converting enzyme inhibitors and angiotensin-2 receptor blockers and acute kidney injury in major elective non-cardiac surgery: a multicentre, prospective cohort study

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    The peri-operative use of angiotensin-converting enzyme inhibitors or angiotensin-2 receptor blockers is thought to be associated with an increased risk of postoperative acute kidney injury. To reduce this risk, these agents are commonly withheld during the peri-operative period. This study aimed to investigate if withholding angiotensin-converting enzyme inhibitors or angiotensin-2 receptor blockers peri-operatively reduces the risk of acute kidney injury following major non-cardiac surgery. Patients undergoing elective major surgery on the gastrointestinal tract and/or the liver were eligible for inclusion in this prospective study. The primary outcome was the development of acute kidney injury within seven days of operation. Adjusted multi-level models were used to account for centre-level effects and propensity score matching was used to reduce the effects of selection bias between treatment groups. A total of 949 patients were included from 160 centres across the UK and Republic of Ireland. From this population, 573 (60.4%) patients had their angiotensin-converting enzyme inhibitors or angiotensin-2 receptor blockers withheld during the peri-operative period. One hundred and seventy-five (18.4%) patients developed acute kidney injury; there was no difference in the incidence of acute kidney injury between patients who had their angiotensin-converting enzyme inhibitors or angiotensin-2 receptor blockers continued or withheld (107 (18.7%) vs. 68 (18.1%), respectively; p = 0.914). Following propensity matching, withholding angiotensin-converting enzyme inhibitors or angiotensin-2 receptor blockers did not demonstrate a protective effect against the development of postoperative acute kidney injury (OR (95%CI) 0.89 (0.58–1.34); p = 0.567)

    Temperament and Behavior in Toddlers of Mothers with Bipolar Disorder: A Preliminary Investigation of a Population at High Familial Risk for Psychopathology

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    Objective: There are no published studies examining concurrent associations between temperament and behavior during toddlerhood in offspring of parents with bipolar disorder (OBD), a population at high familial risk for psychopathology. Better understanding of early determinants contributing to well-being or mental illness in this high-risk population has the potential to aid in the identification of problem domains to be targeted clinically, and facilitate the development of early intervention and prevention initiatives for an appropriate subgroup of children at the youngest possible age. Methods: A total of 30 offspring of mothers with BD (mean age=25.4±4.9 months) participated in this study at Emory University. The mothers completed the Early Childhood Behavior Questionnaire (ECBQ) and the Child Behavior Checklist (CBCL). Results: The results of the correlational analyses indicated that the broad temperament dimension Negative Affectivity and the individual ECBQ scales Sadness and Shyness were positively associated with the broad CBCL dimension Internalizing Problems, whereas Sociability was negatively associated with Internalizing Problems. In addition, the temperament scales Soothability and Frustration were negatively and positively associated with Internalizing Problems, respectively. All ECBQ scales included in the broad temperament dimension Effortful Control, except for Cuddliness, were significantly negatively associated with the broad CBCL dimension Externalizing Problems. A significant sex difference was found for the ECBQ scale Positive Anticipation and the CBCL scale Sleep Problems, with a higher mean rank score for girls than for boys. Conclusions: This is the first systematic investigation of temperament and behavior and concurrent associations between these two domains in toddlers of mothers with BD. The present findings provide a platform for future investigations of the contribution of temperament and early behavior to potential well-being or mental illness in OBD

    Targeting fatty acid oxidation enhances response to HER2-targeted therapy

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    Abstract Metabolic reprogramming, a hallmark of tumorigenesis, involves alterations in glucose and fatty acid metabolism. Here, we investigate the role of Carnitine palmitoyl transferase 1a (Cpt1a), a key enzyme in long-chain fatty acid (LCFA) oxidation, in ErbB2-driven breast cancers. In ErbB2+ breast cancer models, ablation of Cpt1a delays tumor onset, growth, and metastasis. However, Cpt1a-deficient cells exhibit increased glucose dependency that enables survival and eventual tumor progression. Consequently, these cells exhibit heightened oxidative stress and upregulated nuclear factor erythroid 2-related factor 2 (Nrf2) activity. Inhibiting Nrf2 or silencing its expression reduces proliferation and glucose consumption in Cpt1a-deficient cells. Combining the ketogenic diet, composed of LCFAs, or an anti-ErbB2 monoclonal antibody (mAb) with Cpt1a deficiency significantly perturbs tumor growth, enhances apoptosis, and reduces lung metastasis. Using an immunocompetent model, we show that Cpt1a inhibition promotes an antitumor immune microenvironment, thereby enhancing the efficacy of anti-ErbB2 mAbs. Our findings underscore the importance of targeting fatty acid oxidation alongside HER2-targeted therapies to combat resistance in HER2+ breast cancer patients
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