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Search Results: 1 - 10 of 9431 matches for " Angela Teresita Lisa "
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Different Effects of Mg2+ and Zn2+ on the Two Sites for Alkylammonium Compounds in Pseudomonas aeruginosa Phosphorylcholine Phosphatase
Lisandro Horacio Otero,Paola Rita Beassoni,Cristhian Boetsch,Angela Teresita Lisa,Carlos Eduardo Domenech
Enzyme Research , 2011, DOI: 10.4061/2011/918283
Abstract: Pseudomonas aeruginosa phosphorylcholine phosphatase (PchP) catalyzes the hydrolysis of phosphorylcholine (Pcho), is activated by Mg2+ or Zn2+, and is inhibited by high concentrations of substrate. This study has shown that PchP contains two sites for alkylammonium compounds (AACs): one in the catalytic site near the metal ion-phosphoester pocket, and the other in an inhibitory site responsible for the binding of the alkylammonium moiety. The catalytic mechanism for the entry of Pcho in both sites and Zn2+ or Mg2+ follows a random sequential mechanism. However, Zn2+ is more effective than Mg2+ at alleviating the inhibition produced by the entry of Pcho or different AACs in the inhibitory site. We postulate that Zn2+ induces a conformational change in the active center that is communicated to the inhibitory site, producing a compact or closed structure. In contrast, Mg2+ produces a relaxed or open conformation. 1. Introduction Pseudomonas aeruginosa phosphorylcholine phosphatase (PchP) catalyzes the hydrolysis of phosphorylcholine (Pcho) [1]. Pcho is the product of the action of hemolytic phospholipase C (PlcH) on phosphatidylcholine or sphingomyelin and is hydrolyzed to choline and inorganic phosphate (Pi) by the action of PchP. Thus, both the PlcH and PchP enzymes are involved in the pathogenesis of P. aeruginosa [2]. PchP contains three motifs that are characteristic of the enzymes belonging to the haloacid dehalogenase (HAD) superfamily [3]. Moreover, all three motifs have an important role in the catalytic process of Pcho or p-nitrophenylphosphate (p-NPP) in the presence of Mg2+, Zn2+, or Cu2+ as activators of the enzyme [4]. Using Pcho as the substrate, we have shown that Mg2+ is an equal activator for the enzyme at pH 5.0 and at pH 7.4; however, Zn2+ is an activator at pH 5.0 but an inhibitor at pH 7.4. The inhibition produced by Zn2+ at pH 7.4 is reversible and occurs in the presence or absence of Mg2+. This activation or inhibition of PchP by Zn2+ is caused by the transition from octahedral to tetrahedral geometry in the coordination sphere of the metal ion [5]. These results, in combination with the fact that PchP is inhibited by high Pcho concentrations and previous observations that different AACs may act as inhibitors of PchP [1, 6, 7], led us to evaluate the catalytic mechanism of PchP with Pcho as the substrate, Mg2+ or Zn2+ as activators, and AACs as inhibitors. 2. Materials and Methods 2.1. Materials Isopropyl-β-D-thiogalactopyranoside (IPTG) and HisLinkTM resin were purchased from Promega. Pcho and p-NPP were purchased from
Phosphorylcholine Phosphatase: A Peculiar Enzyme of Pseudomonas aeruginosa
Carlos Eduardo Domenech,Lisandro Horacio Otero,Paola Rita Beassoni,Angela Teresita Lisa
Enzyme Research , 2011, DOI: 10.4061/2011/561841
Abstract: Pseudomonas aeruginosa synthesizes phosphorylcholine phosphatase (PchP) when grown on choline, betaine, dimethylglycine or carnitine. In the presence of Mg2+ or Zn2+, PchP catalyzes the hydrolysis of p-nitrophenylphosphate (p-NPP) or phosphorylcholine (Pcho). The regulation of pchP gene expression is under the control of GbdR and NtrC; dimethylglycine is likely the metabolite directly involved in the induction of PchP. Therefore, the regulation of choline metabolism and consequently PchP synthesis may reflect an adaptive response of P. aeruginosa to environmental conditions. Bioinformatic and biochemistry studies shown that PchP contains two sites for alkylammonium compounds (AACs): one in the catalytic site near the metal ion-phosphoester pocket, and another in an inhibitory site responsible for the binding of the alkylammonium moiety. Both sites could be close to each other and interact through the residues 42E, 43E and 82YYY84. Zn2+ is better activator than Mg2+ at pH 5.0 and it is more effective at alleviating the inhibition produced by the entry of Pcho or different AACs in the inhibitory site. We postulate that Zn2+ induces at pH 5.0 a conformational change in the active center that is communicated to the inhibitory site, producing a compact or closed structure. However, at pH 7.4, this effect is not observed because to the hydrolysis of the [Zn2+L2 ?1L2 0(H2O)2] complex, which causes a change from octahedral to tetrahedral in the metal coordination geometry. This enzyme is also present in P. fluorescens, P. putida, P. syringae, and other organisms. We have recently crystallized PchP and solved its structure. 1. Introduction Bacteria possess multiple proteins with the capacity to catalyze the hydrolysis of phosphoric esters in either acidic or alkaline media. In addition to having different optimal pH values for their activity, these enzymes differ in their dependence on metal ions, which are generally divalent cations found in the second or third period of the periodic table. In our previous review, we summarized work showing that the synthesis of Pseudomonas aeruginosa phosphorylcholine phosphatase (PchP) in the presence of low or high orthophosphate concentration depends on choline, betaine, dimethylglycine, or carnitine added to the culture medium as the carbon and/or nitrogen source. In addition, the gene for PchP was located, and the most current information on the kinetic, biochemical, biophysical, and molecular characteristics of PchP was summarized [1]. Phosphorylcholine (Pcho), phosphorylethanolamine, and p-nitrophenylphosphate (p-NPP),
Pneumococcal Meningitis during Pregnancy: A Case Report and Review of Literature
Lisa M. Landrum,Angela Hawkins,Jean Ricci Goodman
Infectious Diseases in Obstetrics and Gynecology , 2007, DOI: 10.1155/2007/63624
Abstract: Background. Bacterial meningitis is a medical emergency for which prompt diagnosis and treatment are imperative to reducing the rate of death and long-term neurologic compromise. Few cases of meningitis have been reported during pregnancy, many of which had devastating outcomes for mother, neonate, or both. Case. A 38-year-old multigravida at 35 weeks of gestation presented with mental status changes, fever, and preterm contractions. Lumbar puncture revealed gram positive cocci consistent with S. pneumoniae. Patient was intubated and admitted to ICU where she was given antibiotics and adjunctive therapy with dexamethasone. Continuous fetal monitoring was utilized throughout her course of her hospitalization. Patient was discharged home after ten days in the hospital and had an uncomplicated vaginal birth after caesarean section (VBAC) at 38 weeks. Both she and the infant are doing well with no permanent neurologic sequelae. Conclusion. A review of literature indicates only isolated cases of pneumococcal meningitis being described during pregnancy. An extended period of time between onset of maternal illness and delivery appears to reduce the risk of neonatal transmission and improve both maternal and fetal outcomes.
Availability, prices and affordability of the World Health Organization’s essential medicines for children in Guatemala
Angela Anson, Brooke Ramay, Antonio de Esparza, Lisa Bero
Globalization and Health , 2012, DOI: 10.1186/1744-8603-8-22
Abstract: An adaption of the standardized methodology developed by the World Health Organization and Health Action International (HAI) was used to conduct a cross sectional survey to collect data on availability and final patient prices of medicines in public and private sector medicine outlets during April and May of 2010.A subset of the public sector, Programa de Accesibilidad a los Medicamentos (PROAM), had the lowest average availability (25%) compared to the private sector (35%). In the private sector, highest and lowest priced medicines were 22.7 and 10.7 times more expensive than their international reference price comparison. Treatments were generally unaffordable, costing as much as 15 days wages for a course of ceftriaxone.Analysis of the procurement, supply and distribution of specific medicines is needed to determine reasons for lack of availability. Improvements to accessibility could be made by developing an essential medicines list for children and including these medicines in national purchasing lists.Children in poorer countries are more likely to die from treatable conditions than those in higher resource settings because they do not receive appropriate or timely medications [1]. This is also true in Guatemala, where poverty contributes to the country’s high mortality rate for children under the age of five [2]. Millennium Development Goal 4 (MDG4) states that a two-thirds reduction in mortality from 1990 to 2015 in children younger than five years is essential for global development [3]. Compared to the rate of mortality in 1990, Guatemala will need to increase the rate of decline in childhood deaths from 75.8 to 25.3 deaths per 1000 to achieve the MDG goal by 2015 [4]. To assist member countries with achieving MDG4, the WHO constructed the first Essential Medicines List for Children (EMLc) and launched the “Make Medicines Child Size” effort in December of 2007. This initiative aims to improve the accessibility of safe, effective and quality medicines for c
Weight Loss Maintenance in African American Women: A Systematic Review of the Behavioral Lifestyle Intervention Literature
Lisa M. Tussing-Humphreys,Marian L. Fitzgibbon,Angela Kong,Angela Odoms-Young
Journal of Obesity , 2013, DOI: 10.1155/2013/437369
Abstract: We performed a systematic review of the behavioral lifestyle intervention trials conducted in the United States published between 1990 and 2011 that included a maintenance phase of at least six months, to identify intervention features that promote weight loss maintenance in African American women. Seventeen studies met the inclusion criteria. Generally, African American women lost less weight during the intensive weight loss phase and maintained a lower % of their weight loss compared to Caucasian women. The majority of studies failed to describe the specific strategies used in the delivery of the maintenance intervention, adherence to those strategies, and did not incorporate a maintenance phase process evaluation making it difficult to identify intervention characteristics associated with better weight loss maintenance. However, the inclusion of cultural adaptations, particularly in studies with a mixed ethnicity/race sample, resulted in less % weight regain for African American women. Studies with a formal maintenance intervention and weight management as the primary intervention focus reported more positive weight maintenance outcomes for African American women. Nonetheless, our results present both the difficulty in weight loss and maintenance experienced by African American women in behavioral lifestyle interventions. 1. Introduction Overweight (body mass index (BMI) 25.0–29.9?kg/m2) and obesity (BMI ≥ 30?kg/m2) are global public health problems [1, 2]. All demographic sectors of the United States (US) population are affected, but African American (AA) women are disproportionately burdened [1, 3]. As reported in 2012 (National Health and Nutrition Examination Survey (NHANES), 2009-2010), approximately 82% of AA adult women in the US were classified as overweight or obese [1]. This disparity is of particular concern given that overweight and obesity are associated with a number of serious chronic diseases [4, 5]. The most common approach to obesity treatment includes lifestyle interventions that target both diet and physical activity (PA) and some form of behavioral self-management [6–9]. Traditionally, AA women enrolled in behavioral lifestyle interventions lose less weight when compared to other subgroups [3, 10–16] although even modest weight reduction improves the cardiovascular risk profile [17, 18] and decreases diabetes incidence [19]. If weight loss is not sustained, the health benefits of weight reduction are attenuated [20, 21]. This fact highlights the importance of understanding factors that support long-term weight control across
The Aging Waistline: Impact of the Geriatric Obesity Epidemic on an Urban Emergency Department: Original Communication  [PDF]
Heather M. Prendergast, Ernest Waintraub, Brad Bunney, Lisa Gehm, Carissa Tyo, Armando Marquez, John Williams, Angela Bailey, Diego Marquez, Marcia Edison, Mark Mackey
International Journal of Clinical Medicine (IJCM) , 2013, DOI: 10.4236/ijcm.2013.45047
Abstract:

Purpose: Reviews adult emergency department (ED) visits for patients age 65 and older during one calendar year; determine the prevalence of weight classifications; identifies trends between BMI and discharge/admitting diagnoses, vital signs, and severity index.Methods: The electronic medical records system and data from the ED billing service was reviewed for an urban academic institution with an annual volume of 125,000 for patients age > 65. Using a random number table, a retrospective cohort of 328 elderly patients was selected for review, representing a convenience sample of 2.6% of elderly ED visits. Body Mass Index (BMI) was calculated, using the Center for Disease Control (CDC) formula with underweight (<18.5), normal (18.5 - 24.9), overweight (25 - 29.9), and obese (≥30). Results: The majority of the cohort in this study was African-American and Hispanic (60% and 27% respectively), and there were a higher percentage of females than males (60% and 40% respectively). Approximately 29% of the patients were classified as normal weight, 35% classified as overweight, and 36% as obese. The older the patient, the more likely that patient belonged to a lower weight classification (p < 0.01). Those presenting with neurological, pulmonary or gastrointestinal complaints were more likely to be of a higher weight classification (p < 0.05). Patients who were hypertensive on arri

Memorias de mujeres centroamericanas vinculadas a una organización comunitaria
Cordero,Teresita;
Diálogos Revista Electrónica de Historia , 2011,
Abstract: the following document presents the data analysis of forty-six autobiographies, short stories or references to women participating in the mother-teacher organization (omma) from three central american countries. it is the result of an investigation conducted by the university of costa rica at the institute of research (inie) for this reason include the frame of reference, methodology and results. it ends with a reflection on the experience of women and the importance of community organizing for the opening of opportunities that this group has developed in the context of poor women.
50 a?os de la Revista de Biología Tropical: Contribución al desarrollo de la Geo-Paleontología
Aguilar,Teresita;
Revista de Biología Tropical , 2002,
Abstract: the geosciences contribution along the 50 years of the revista de biología tropical had been scarcity and episodic. until now there are 2374 papers but only 21 (0.88%) have some relation with geological sciencies. it`s posible to reconize two periods with geological contributions, one between 1963 and 1978. it`s appropiate to underline the importance of the biologist l. d. gómez with his contributions about costa rican paleobotanic in this period. the other period includes from 1988 to the present, and it`s tipyfied by an increase of biologist and geologist participation in different topics regarding with geosciences. foreing and national researches are in the same ratio and belong from several contries like costa rica, méxico and dominican repubic. the subjects are concerning mainly about fossil taxonomy (paleontology: 81%), only 19% are related with geological topics. such distribution could be explained because the affinity between the fossil studies and the biological sciences
50 a os de la Revista de Biología Tropical: Contribución al desarrollo de la Geo-Paleontología
Teresita Aguilar
Revista de Biología Tropical , 2002,
Abstract: Las contribuciones sobre temas geocientíficos en los 50 a os de la Revista de Biología Tropical ha sido muy escaza y episódica. De los 2i374 artículos publicados hasta la fecha, solamente 21 (0.88%) tienen alguna relación con las geociencias. Se pueden reconocer dos etapas de aportes relacionados con las ciencias geológicas, la primera entre 1963 - 1978, destacándose en ésta época los trabajos sobre la paleobotánica de Costa Rica realizados por el biólogo L. D. Gómez. La segunda etapa se inicia en 1988 y se continúa hasta la actualidad, con un incremento en la participación de biólogos y geólogos. La participación relativa entre nacionales y extranjeros ha sido muy equilibrada y los lugares tratados incluyen en orden de importancia Costa Rica, México, República Dominicana y algunos de interés general. Los temas han sido principalmente sobre diversos campos de la Paleontología (81%), constituyendo los temas netamente geológicos sólo el 19%. Esto se puede explicar por la mayor afinidad que existe entre el estudio de los fósiles y la Biología The geosciences contribution along the 50 years of the Revista de Biología Tropical had been scarcity and episodic. Until now there are 2374 papers but only 21 (0.88%) have some relation with geological sciencies. It`s posible to reconize two periods with geological contributions, one between 1963 and 1978. It`s appropiate to underline the importance of the biologist L. D. Gómez with his contributions about Costa Rican Paleobotanic in this period. The other period includes from 1988 to the present, and it`s tipyfied by an increase of biologist and geologist participation in different topics regarding with geosciences. Foreing and national researches are in the same ratio and belong from several contries like Costa Rica, México and Dominican Repubic. The subjects are concerning mainly about fossil taxonomy (Paleontology: 81%), only 19% are related with geological topics. Such distribution could be explained because the affinity between the fossil studies and the biological sciences
A Systematic Review and Meta-Analysis of Utility-Based Quality of Life in Chronic Kidney Disease Treatments
Melanie Wyld ,Rachael Lisa Morton,Andrew Hayen,Kirsten Howard,Angela Claire Webster
PLOS Medicine , 2012, DOI: 10.1371/journal.pmed.1001307
Abstract: Background Chronic kidney disease (CKD) is a common and costly condition to treat. Economic evaluations of health care often incorporate patient preferences for health outcomes using utilities. The objective of this study was to determine pooled utility-based quality of life (the numerical value attached to the strength of an individual's preference for a specific health outcome) by CKD treatment modality. Methods and Findings We conducted a systematic review, meta-analysis, and meta-regression of peer-reviewed published articles and of PhD dissertations published through 1 December 2010 that reported utility-based quality of life (utility) for adults with late-stage CKD. Studies reporting utilities by proxy (e.g., reported by a patient's doctor or family member) were excluded. In total, 190 studies reporting 326 utilities from over 56,000 patients were analysed. There were 25 utilities from pre-treatment CKD patients, 226 from dialysis patients (haemodialysis, n = 163; peritoneal dialysis, n = 44), 66 from kidney transplant patients, and three from patients treated with non-dialytic conservative care. Using time tradeoff as a referent instrument, kidney transplant recipients had a mean utility of 0.82 (95% CI: 0.74, 0.90). The mean utility was comparable in pre-treatment CKD patients (difference = ?0.02; 95% CI: ?0.09, 0.04), 0.11 lower in dialysis patients (95% CI: ?0.15, ?0.08), and 0.2 lower in conservative care patients (95% CI: ?0.38, ?0.01). Patients treated with automated peritoneal dialysis had a significantly higher mean utility (0.80) than those on continuous ambulatory peritoneal dialysis (0.72; p = 0.02). The mean utility of transplant patients increased over time, from 0.66 in the 1980s to 0.85 in the 2000s, an increase of 0.19 (95% CI: 0.11, 0.26). Utility varied by elicitation instrument, with standard gamble producing the highest estimates, and the SF-6D by Brazier et al., University of Sheffield, producing the lowest estimates. The main limitations of this study were that treatment assignments were not random, that only transplant had longitudinal data available, and that we calculated EuroQol Group EQ-5D scores from SF-36 and SF-12 health survey data, and therefore the algorithms may not reflect EQ-5D scores measured directly. Conclusions For patients with late-stage CKD, treatment with dialysis is associated with a significant decrement in quality of life compared to treatment with kidney transplantation. These findings provide evidence-based utility estimates to inform economic evaluations of kidney therapies, useful for policy
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