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Silva MP, Rodrigues CG, Machado DC, Nogueira RA. Long-term memory in Staphylococcus aureus α-hemolysin ion channel kinetics. Eur Biophys J 2023; 52:661-671. [PMID: 37542583 DOI: 10.1007/s00249-023-01675-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/20/2022] [Revised: 07/03/2023] [Accepted: 07/20/2023] [Indexed: 08/07/2023]
Abstract
The kinetics of an ion channel are classically understood as a random process. However, studies have shown that in complex ion channels, formed by multiple subunits, this process can be deterministic, presenting long-term memory. Staphylococcus aureus α-hemolysin (α-HL) is a toxin that acts as the major factor in Staphylococcus aureus virulence. α-HL is a water-soluble protein capable of forming ion channels into lipid bilayers, by insertion of an amphipathic β-barrel. Here, the α-HL was used as an experimental model to study memory in ion channel kinetics. We applied the approximate entropy (ApEn) approach to analyze randomness and the Detrended Fluctuation Analysis (DFA) to investigate the existence of long memory in α-HL channel kinetics. Single-channel currents were measured through experiments with α-HL channels incorporated in planar lipid bilayers. All experiments were carried out under the following conditions: 1 M NaCl solution, pH 4.5; transmembrane potential of + 40 mV and temperature 25 ± 1 °C. Single-channel currents were recorded in real-time in the memory of a microcomputer coupled to an A/D converter and a patch-clamp amplifier. The conductance value of the α-HL channels was 0.82 ± 0.0025 nS (n = 128). The DFA analysis showed that the kinetics of α-HL channels presents long-term memory ([Formula: see text] = 0.63 ± 0.04). The ApEn outcomes showed low complexity to dwell times when open (ApEno = 0.5514 ± 0.28) and closed (ApEnc = 0.1145 ± 0.08), corroborating the results of the DFA method.
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Affiliation(s)
- M P Silva
- Department of Animal Morphology and Physiology, Federal Rural University of Pernambuco, Recife, Pernambuco, Brazil
| | - C G Rodrigues
- Department of Biophysics and Radiobiology, Federal University of Pernambuco, Recife, Pernambuco, Brazil
| | - D C Machado
- Department of Biophysics and Radiobiology, Federal University of Pernambuco, Recife, Pernambuco, Brazil
| | - R A Nogueira
- Department of Animal Morphology and Physiology, Federal Rural University of Pernambuco, Recife, Pernambuco, Brazil.
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2
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Dumith SC, Martins OPL, Moreira MKV, Paulitsch RG, Simões MO, Marmitt LP, Silva PEA, Silva MP. Is the increment of diabetes mellitus in Brazil associated with the consumption of artificially sweetened beverages? A time trend analysis with 757,386 adults from 2006 to 2020. Public Health 2023; 221:66-72. [PMID: 37421755 DOI: 10.1016/j.puhe.2023.06.004] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2023] [Revised: 05/19/2023] [Accepted: 06/06/2023] [Indexed: 07/10/2023]
Abstract
OBJECTIVE To describe trends in the prevalence of diabetes mellitus (DM) in Brazil and to analyze its association with the consumption of artificially sweetened beverages among individuals aged 18 years or older. STUDY DESIGN This was a repeated cross-sectional study. METHODS Annual data from VIGITEL surveys (2006-2020) were used, which included adults from all Brazilian state capitals. The outcome was the prevalence of DM (type 1 and type 2). The main exposure variable was consuming beverages like soft drinks and artificial juices, either in its 'diet, light, or zero' form. Covariates included sex, age, sociodemographic characteristics, smoking, alcohol consumption, physical activity, fruit consumption, and obesity. The temporal trend in the indicators and the etiological fraction (population attributable risk [PAR]) were calculated. Analyses were performed using Poisson regression. The association between DM and consumption of beverages was tested, excluding the year 2020 due to the pandemic; restricting the analysis to the final three years (2018-2020). RESULTS Overall, 757,386 subjects were included. The prevalence of DM increased from 5.5% to 8.2%, with an annual growth of 0.17 percentage points (95% CI 0.11-0.24). Among those who consumed diet/light/zero beverages, the annual percentage change of DM was four times greater. The PAR corresponding to the consumption of diet/light/zero beverages on the occurrence of DM was 17%. CONCLUSIONS An increasing prevalence of DM was observed, while diet/light/zero beverages consumption remains stable. A substantial reduction in the annual percentage change of DM could be observed if people stopped consuming diet/light soda/juice.
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Affiliation(s)
- S C Dumith
- Postgraduate Program in Health Sciences, Universidade Federal de Rio Grande. Rio Grande, RS, CEP: 96203-900, Brazil; Grupo de Pesquisa em Atividade Física e Saúde Pública, Universidade Federal do Rio Grande, Rio Grande, RS, CEP: 96203-900, Brazil
| | - O P L Martins
- Postgraduate Program in Health Sciences, Universidade Federal de Rio Grande. Rio Grande, RS, CEP: 96203-900, Brazil; Grupo de Pesquisa em Atividade Física e Saúde Pública, Universidade Federal do Rio Grande, Rio Grande, RS, CEP: 96203-900, Brazil
| | - M K V Moreira
- Grupo de Pesquisa em Atividade Física e Saúde Pública, Universidade Federal do Rio Grande, Rio Grande, RS, CEP: 96203-900, Brazil; Postgraduate Program in Epidemiology, Universidade Federal de Pelotas, Pelotas, RS, CEP: 96020-220, Brazil
| | - R G Paulitsch
- Grupo de Pesquisa em Atividade Física e Saúde Pública, Universidade Federal do Rio Grande, Rio Grande, RS, CEP: 96203-900, Brazil; Empresa Brasileira de Serviços Hospitalares, Universidade Federal do Rio Grande, Rio Grande, RS, CEP: 96203-900, Brazil
| | - M O Simões
- Grupo de Pesquisa em Atividade Física e Saúde Pública, Universidade Federal do Rio Grande, Rio Grande, RS, CEP: 96203-900, Brazil; Universidade Vale do Rio Doce, Governador Valadares, MG, CEP: 35020-220, Brazil
| | - L P Marmitt
- Grupo de Pesquisa em Atividade Física e Saúde Pública, Universidade Federal do Rio Grande, Rio Grande, RS, CEP: 96203-900, Brazil; Postgraduate Program in Biosciences and Health, Universidade do Oeste de Santa Catarina, Joaçaba, SC, CEP: 89600-000, Brazil.
| | - P E A Silva
- Postgraduate Program in Health Sciences, Universidade Federal de Rio Grande. Rio Grande, RS, CEP: 96203-900, Brazil
| | - M P Silva
- Postgraduate Program in Health Sciences, Universidade Federal de Rio Grande. Rio Grande, RS, CEP: 96203-900, Brazil; Grupo de Pesquisa em Atividade Física e Saúde Pública, Universidade Federal do Rio Grande, Rio Grande, RS, CEP: 96203-900, Brazil
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Calvao J, Braga M, Brandao M, Campinas A, Alexandre A, Amador AF, Costa C, Carvalho MM, Pinto RA, Proenca T, Silva JC, Pires-Morais G, Silva MP, Brochado B, Macedo F. Acute total occlusion of the unprotected left main coronary artery – patient characteristics and outcomes. Eur Heart J 2022. [DOI: 10.1093/eurheartj/ehac544.1488] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Abstract
Background
Acute total occlusion of the unprotected left main coronary artery (ATOLMCA) is a dramatic entity with very high mortality. Owing to its infrequency, there is limited and inconsistent data regarding this population.
Purpose
To describe the clinical presentation, short- and long-term outcomes of patients with ATOLMCA.
Methods
This retrospective multicentric cohort study included all patients presenting with acute (<12h) myocardial infarction (MI) due to ATOLMCA (Thrombolysis In Myocardial Infarction - TIMI=0) between January 2008 and December 2020 in three tertiary hospitals.
Results
In the period of the study, 11,036 emergent coronary angiographies were performed in the participating centers, 59 of which were ATOLMCA (0.5%). Mean age of patients at the time of the event was 61.2 (±12.2) years. Seventy-three percent were male. At presentation, 72.9% of patients were in cardiogenic shock, and aborted cardiac arrest occurred in 27.1%. Right dominance was present in all patients except one, who had a balanced dominance. Primary percutaneous coronary intervention (PCI) was performed in 89.8% of the patients, with angiographic success being achieved in 55.6% of the procedures. Overall, the in-hospital mortality rate was 57.6%. Mortality was significantly higher in patients without angiographic criteria for PCI success (87.5 vs 36.7%, p<0.001). Among survivors, 91.7% were still alive at 1-year and 66.7% at 5 years of follow-up.
Conclusion
Patients with ATOLMCA have a dismal prognosis. Most patients present with cardiogenic shock, and a significant number develop cardiac arrest during the acute phase. Despite medical care, in-hospital mortality is high. Patients with left dominance may not even reach the hospital. Among survivors, long term outcomes are reasonable. Further studies are needed in order to improve the management and outcomes of patients with ATOLMCA.
Funding Acknowledgement
Type of funding sources: None.
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Affiliation(s)
- J Calvao
- Sao Joao Hospital , Porto , Portugal
| | - M Braga
- Sao Joao Hospital , Porto , Portugal
| | - M Brandao
- Hospital Center of Vila Nova de Gaia/Espinho , Vila Nova de Gaia , Portugal
| | - A Campinas
- Hospital Center of Porto , Porto , Portugal
| | | | | | - C Costa
- Sao Joao Hospital , Porto , Portugal
| | | | - R A Pinto
- Sao Joao Hospital , Porto , Portugal
| | - T Proenca
- Sao Joao Hospital , Porto , Portugal
| | - J C Silva
- Sao Joao Hospital , Porto , Portugal
| | - G Pires-Morais
- Hospital Center of Vila Nova de Gaia/Espinho , Vila Nova de Gaia , Portugal
| | - M P Silva
- Hospital Center of Vila Nova de Gaia/Espinho , Vila Nova de Gaia , Portugal
| | - B Brochado
- Hospital Center of Porto , Porto , Portugal
| | - F Macedo
- Sao Joao Hospital , Porto , Portugal
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Abstract
Ion channels are transport proteins present in the lipid bilayers of biological membranes. They are involved in many physiological processes, such as the generation of nerve impulses, hormonal secretion, and heartbeat. Conformational changes in the ion channel-forming protein allow the opening or closing of pores to control the ionic flux through the cell membranes. The opening and closing of the ion channel have been classically treated as a random kinetic process, known as a Markov process. Here the time the channel remains in a given state is assumed to be independent of the condition it had in the previous state. More recently, however, several studies have shown that this process is not random but a deterministic one, where both the open and closed dwell-times and the ionic current flowing through the channel are history-dependent. This property is called long memory or long-range correlation. However, there is still much controversy regarding how this memory originates, which region of the channel is responsible for this property, and which models could best reproduce the memory effect. In this article, we provide a review of what is, where it is, its possible origin, and the mathematical methods used to analyze the long-term memory present in the kinetic process of ion channels.
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Affiliation(s)
- M P Silva
- Department of Animal Morphology and Physiology, Federal Rural University of Pernambuco, Recife, Pernambuco, Brazil
| | - C G Rodrigues
- Department of Biophysics and Radiobiology, Federal University of Pernambuco, Recife, Pernambuco, Brazil
| | - W A Varanda
- Department of Physiology-Faculty of Medicine of Ribeirão Preto, University of São Paulo (Retired), Ribeirão Preto, São Paulo, Brazil
| | - R A Nogueira
- Department of Animal Morphology and Physiology, Federal Rural University of Pernambuco, Recife, Pernambuco, Brazil.
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Silva MP, Jacinto DM, Fuchs TA, Takihi IY, Gouvea CP, Chauffaille MLLF, Perazzio ADSB, Silva MCA, Sandes AF, Gonçalves MV. TROMBOCITOPENIA MEDICAMENTOSA: O ANTIGO E O NOVO. Hematol Transfus Cell Ther 2021. [DOI: 10.1016/j.htct.2021.10.740] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022] Open
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Calandrini TSS, Miquilini L, Laranjeiras-Neto MR, Tongu MTS, Silva MP, Souza GS, Cortes MIT. Preliminary data for performance in hue ordering tests during pregnancy. Braz J Med Biol Res 2019; 52:e7559. [PMID: 30698224 PMCID: PMC6345356 DOI: 10.1590/1414-431x20187559] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2018] [Accepted: 11/21/2018] [Indexed: 11/22/2022] Open
Abstract
The visual system of women changes during pregnancy. Few reports have addressed the effects of pregnancy on color vision. We aimed to compare the color vision of women in the first, second, and third trimesters of pregnancy. Fifty women were divided into first (n=10), second (n=10), third trimester pregnancy groups (n=10), and non-pregnant group (n=20). We used the Farnsworth D15 and Lanthony desaturated D15 (D15d) tests. The hue ordering quantified the amount of error (C-index) and the chromatic selectivity of the errors (S-index). Bland-Altman analysis was applied to the hue ordering data. No difference was found for Farnsworth D15 test results obtained from the pregnant groups and the non-pregnant group (P<0.0083). For the Lanthony D15 desaturated test, the third trimester pregnant group had higher C-index and S-index than non-pregnant women and first-trimester pregnant women (P<0.0083). The Bland-Altman analysis showed that the limits of agreement increased as pregnancy advanced, and the errors were biased to the D15d test. In this study, color vision was impaired during pregnancy. Color vision evaluation could be used as an indicator of the functional status of the central vision during pregnancy.
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Affiliation(s)
- T S S Calandrini
- Programa de Pós-Graduação em Ciências da Saúde, Universidade Federal do Amapá, Macapá, AP, Brasil
| | - L Miquilini
- Núcleo de Medicina Tropical, Universidade Federal do Pará, Belém, PA, Brasil
| | - M R Laranjeiras-Neto
- Programa de Pós-Graduação em Ciências da Saúde, Universidade Federal do Amapá, Macapá, AP, Brasil
| | - M T S Tongu
- Programa de Pós-Graduação em Ciências da Saúde, Universidade Federal do Amapá, Macapá, AP, Brasil
| | - M P Silva
- Programa de Pós-Graduação em Ciências da Saúde, Universidade Federal do Amapá, Macapá, AP, Brasil
| | - G S Souza
- Núcleo de Medicina Tropical, Universidade Federal do Pará, Belém, PA, Brasil
| | - M I T Cortes
- Programa de Pós-Graduação em Ciências da Saúde, Universidade Federal do Amapá, Macapá, AP, Brasil
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7
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Fontes T, Silva LM, Silva MP, Barros N, Carvalho AC. Can artificial neural networks be used to predict the origin of ozone episodes? Sci Total Environ 2014; 488-489:197-207. [PMID: 24830932 DOI: 10.1016/j.scitotenv.2014.04.077] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/05/2014] [Revised: 04/07/2014] [Accepted: 04/20/2014] [Indexed: 06/03/2023]
Abstract
Tropospheric ozone is a secondary pollutant having a negative impact on health and environment. To control and minimize such impact the European Community established regulations to promote a clean air all over Europe. However, when an episode is related with natural mechanisms as Stratosphere-Troposphere Exchanges (STE), the benefits of an action plan to minimize precursor emissions are inefficient. Therefore, this work aims to develop a tool to identify the sources of ozone episodes in order to minimize misclassification and thus avoid the implementation of inappropriate air quality plans. For this purpose, an artificial neural network model - the Multilayer Perceptron - is used as a binary classifier of the source of an ozone episode. Long data series, between 2001 and 2010, considering the ozone precursors, (7)Be activity and meteorological conditions were used. With this model, 2-7% of a mean error was achieved, which is considered as a good generalization. Accuracy measures for imbalanced data are also discussed. The MCC values show a good performance of the model (0.65-0.92). Precision and F1-measure indicate that the model specifies a little better the rare class. Thus, the results demonstrate that such a tool can be used to help authorities in the management of ozone, namely when its thresholds are exceeded due natural causes, as the above mentioned STE. Therefore, the resources used to implement an action plan to minimize ozone precursors could be better managed avoiding the implementation of inappropriate measures.
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Affiliation(s)
- T Fontes
- University Fernando Pessoa, Global Change, Energy, Environment and Bioengineering Center (CIAGEB), Praça 9 de Abril, 349, 4249-004 Porto, Portugal; University of Aveiro, Department of Mechanical Engineering/Centre for Mechanical Technology and Automation, Campus Universitário de Santiago, 3810-193 Aveiro, Portugal.
| | - L M Silva
- University of Aveiro, Department of Mathematics, Campus Universitário de Santiago, 3810-193 Aveiro, Portugal; INEB - Instituto de Engenharia Biomédica, Rua do Campo Alegre, 823, 4150-180 Porto, Portugal
| | - M P Silva
- University Fernando Pessoa, Global Change, Energy, Environment and Bioengineering Center (CIAGEB), Praça 9 de Abril, 349, 4249-004 Porto, Portugal
| | - N Barros
- University Fernando Pessoa, Global Change, Energy, Environment and Bioengineering Center (CIAGEB), Praça 9 de Abril, 349, 4249-004 Porto, Portugal
| | - A C Carvalho
- New University of Lisbon, Faculty of Sciences and Technology/Center for Environmental and Sustainability Research (CENSE), Quinta da Torre, 2829-516 Caparica, Portugal
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8
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Ybarra LF, Ruiz H, Silva MP, Lederman HM, Schettini ST. Ultrasound evaluations of internal jugular vein punction techniques in children: the easiest method to reach the target area. Pediatr Surg Int 2009; 25:99-104. [PMID: 19043722 DOI: 10.1007/s00383-008-2298-2] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 09/30/2008] [Indexed: 11/25/2022]
Abstract
The objective of this study is to determine the best way to access and the position in which the patients must remain in order to obtain the best transversal section of the right internal jugular vein (RIJV) section during the catheterization by ultrasound, allowing a safer and precise access. The three possible ways to access the RIJV, anterior, lateral and posterior, from 57 healthy children, were examined by ultrasound in one similar sequence of positions: horizontal dorsal decubitus with the head centered in neutral position with and without the use of a pillow; horizontal dorsal decubitus with contralateral rotation of the head with and without the use of a pillow; horizontal dorsal decubitus with the head centered in neutral position and the patient in the Trendelenburg position without the use of a pillow. The relation between the different positions and punction regions in RIJV were established using analysis of variance. As a result, the lateral punction with the patient in the Trendelemburg position offered a largest area of the RIJV transversal section in comparison to all the other options (P<0.0001). In conclusion, this study demonstrated that the safer and precise way for the RIJV catheterization in pediatric patients is obtained in Trendelenburg position with lateral access and without a pillow.
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Affiliation(s)
- Luiz Fernando Ybarra
- Pediatric Surgery Division, Surgery Department, Federal University of Sao Paulo, São Paulo, Brazil.
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9
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Borges RC, Nogueira AC, Colombo AS, Nobrega RS, Romero CHM, Pontes VC, Baroni J, Ferreira AM, Caravaggio S, Silva MP, Martins B, Soriano FG. Acute effect of low-dose corticosteroids on muscle function in patients with severe sepsis and septic shock. Crit Care 2009. [PMCID: PMC4085415 DOI: 10.1186/cc7817] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
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10
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Sass N, Itamoto CH, Silva MP, Torloni MR, Atallah AN. Does sodium nitroprusside kill babies? A systematic review. SAO PAULO MED J 2007; 125:108-11. [PMID: 17625709 PMCID: PMC11014698 DOI: 10.1590/s1516-31802007000200008] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/06/2006] [Revised: 03/06/2006] [Accepted: 03/02/2007] [Indexed: 11/22/2022] Open
Abstract
OBJECTIVE To determine whether sodium nitroprusside causes fetal death in pregnancies complicated with hypertension. DATA SOURCES Medical Literature Analysis and Retrieval System Online (MEDLINE; 1996 to 2003), Excerpta Medica (EMBASE; 1970 to 2003), Web of Science/Institute for Scientific Information (ISI; 1945 to 2003), Literatura Latino-Americana e do Caribe em Ciências da Saúde (LILACS; 1982 to 2003) and the Cochrane Library. REVIEW METHODS The medical subject headings used were "nitroprusside and pregnancy", "hypertension or eclampsia or preeclampsia" and "nitroprusside and pregnancy and hypertensive emergencies". The search was limited to humans and female gender, in all fields, publication types, languages and subsets. Articles were also identified by reviewing the references of articles and textbooks on hypertension and pregnancy. RESULTS The search located nine studies. The sum of all the publications yielded a total of 22 patients and 24 exposed fetuses (two pairs of twins). There were no randomized clinical trials and no prospective cohorts. All of the studies were observational in nature. CONCLUSIONS At present, there is insufficient evidence for definitive conclusions about any direct association between sodium nitroprusside use and fetal demise.
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Affiliation(s)
- Nelson Sass
- Obstetrics Department, Universidade Federal de São Paulo Escola Paulista de Medicina, Brazil.
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Abstract
AIM The purpose of the present study was to evaluate microleakage of a fourth generation dentine-bonding agent and composite restoration during a walking bleach treatment. METHODOLOGY Thirty extracted non-carious incisors were selected and conventional root canal treatment was performed. Teeth were randomly divided into 3 groups (n = 10): group A (control), access cavities were restored with a fourth generation dentine-bonding agent, and incrementally restored with composite resin; group B, a paste composed of sodium perborate and hydrogen peroxide was placed into the pulp chamber and sealed with glass ionomer cement for 7 days, teeth were then restored in the same manner as group A; group C, a paste of sodium perborate and hydrogen peroxide was placed in the pulp chamber for 7 days and then after removal of the bleaching mixture, pulp chambers were filled with a calcium hydroxide paste and cavities sealed with glass ionomer for 1 week. The cavities were then restored with bonded restorations as in groups A and B. Teeth were subjected to thermal cycling and immersed in methylene blue for 8 h. Teeth were sectioned from buccal to lingual, through the centre of the restoration, using a diamond disk. Leakage was assessed using a standard scheme, under magnification (x20). Data were submitted to statistical analysis using nonparametric Kruskal-Wallis test. RESULTS Groups A and C exhibited similar leakage patterns, and both demonstrated less leakage values than group B (P < 0.05). CONCLUSIONS It was concluded that bleaching with sodium perborate and hydrogen peroxide increases microleakage; short-term use of a calcium hydroxide medicament did not increase microleakage.
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Affiliation(s)
- F F Demarco
- Department of Operative Dentistry, Faculty of Dentistry, Federal University of Pelotas, RS, Brazil.
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Sarubbo LA, Marçal MC, Neves ML, Silva MP, Porto AL, Campos-Takaki GM. Bioemulsifier production in batch culture using glucose as carbon source by Candida lipolytica. Appl Biochem Biotechnol 2001; 95:59-67. [PMID: 11665807 DOI: 10.1385/abab:95:1:59] [Citation(s) in RCA: 44] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
The yeast Candida lipolytica IA 1055 produced an inducible extracellular emulsification activity while utilizing glucose at different concentrations as carbon source during batch fermentation at 27 degrees C. In all glucose concentrations studied, maximum production of emulsification activity was detected in the stationary phase of growth, after pH reached minimal values. The bioemulsifier isolated was a complex biopolymer constituting proteins, carbohydrates, and lipids. The results obtained in this work show that the biosynthesis of a bioemulsifier is not simply a prerequisite for the degradation of extracellular hydrocarbon.
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Affiliation(s)
- L A Sarubbo
- Departamento de Química, NPCIAMB-UNICAP Rua Nunes Machado, Recife, PE, Brazil
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13
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Araújo FR, Silva MP, Lopes AA, Ribeiro OC, Pires PP, Carvalho CM, Balbuena CB, Villas AA, Ramos JK. Severe cat flea infestation of dairy calves in Brazil. Vet Parasitol 1998; 80:83-6. [PMID: 9877075 DOI: 10.1016/s0304-4017(98)00181-2] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
An investigation was conducted into a severe flea infestation on dairy calves. Inspection of the dairy revealed a high infestation of Ctenocephalides felis felis on four calves and thousands of fleas in the stable where cows and calves were brought in for milking. A 3-month-old female calf was highly infested with fleas. The animal showed an evident lethargy, weight loss, as well as pale mucous membranes and dehydration. Hematological analysis revealed anemia, with 10% packed cell volume and a 1.72 x 10(6) microl(-1) erythrocyte count. Blood transfusions were performed and the flea infestation was controlled with 1% fipronil pour-on (1 ml/10 kg). The farmer was advised to treat the other calves with fipronil, remove the manure from the stable and spread 1% propoxur powder (100 g/m2) onto the floor of the stable.
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Affiliation(s)
- F R Araújo
- Universidade para o Desenvolvimento do Estado e da Região do Pantanal, Campo Grande MS, Brazil. www.flabio.zaz.com.br
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14
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Silva MP, Mira L, Lima J, Manso CF. Kinetics of the inhibition of xanthine dehydrogenase and of the reversible and irreversible forms of xanthine oxidase by silibinin and bendazac. Environ Toxicol Pharmacol 1996; 1:279-284. [PMID: 21781693 DOI: 10.1016/1382-6689(96)00021-x] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/11/1995] [Revised: 03/12/1996] [Accepted: 04/22/1996] [Indexed: 05/31/2023]
Abstract
Xanthine oxidase exists in vivo predominantly as a NAD(+)-dependent dehydrogenase form (xanthine dehydrogenase) which can be transformed into oxygen-dependent oxidase forms as a result of sulfhydryl oxidation (reversible xanthine oxidase) or proteolysis (irreversible xanthine oxidase). Xanthine oxidase has been hypothesized to be a potential source of oxygen-derived free radicals during reperfusion of ischemic tissues. Xanthine dehydrogenase was purified from rat liver and converted into reversible xanthine oxidase by heating at 37 °C and into irreversible xanthine oxidase by proteolysis with trypsin. Silibinin and bendazac are compounds used in therapeutics and to which free radical scavenging properties were ascribed. The effects of the compounds silibinin and bendazac on the different forms of the enzyme were studied. Silibinin inhibited all the forms of the enzyme but bendazac inhibited only reversible and irreversible xanthine oxidase. The inhibitions seem to be mixed non-competitive-competitive. The authors discuss the hypothesis that selective inhibitors of xanthine oxidase, preventing the interruption of uric acid formation, may have some advantage over the inhibitors of both xanthine dehydrogenase and xanthine oxidase in the treatment and prevention of situations such as ischemia and reperfusion syndromes.
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Dos Santos AJ, Nascimento EG, Silva MP, De Carvalho LC. Report on a visceral and cutaneous leishmaniases focus in the town of Jequié, State of Bahia, Brazil. Rev Inst Med Trop Sao Paulo 1993; 35:583-4. [PMID: 7997765 DOI: 10.1590/s0036-46651993000600017] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023] Open
Affiliation(s)
- A J Dos Santos
- Centro de Pesquisas Gonçalo Moniz, Fundação Oswaldo Cruz, Salvador, Bahia, Brazil
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Abstract
A newborn infant was diagnosed as having renal vein thrombosis due to heterozygous protein C deficiency and no other predisposing factor for thrombosis. He responded adequately to treatment with streptokinase, fresh frozen plasma and subsequent anticoagulation with heparin and warfarin (Coumadin). Four years from diagnosis he remains well with no recurrence of thrombosis and with normal renal function.
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Affiliation(s)
- P C Rogers
- Department of Paediatrics, BC Children's Hospital, Vancouver, Canada
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17
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Abstract
Inosinic acid (IMP) has been prepared by the deamination of adenosine monophosphate (AMP) with an immobilized adenosine (phosphate) deaminase extracted from the snail Biomphalaria glabrata. The enzyme has been immobilized in polyacrylamide beads. The preparation and characterization of this system are described.
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Affiliation(s)
- L B Carvalho Júnior
- Departamento de Bioquimica, Universidade Federal de Pernambuco, Cidade Universitaria, Recife, PE, Brasil
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Gallucci C, Forte V, Buffollo E, Catani R, Godoy MF, Guerra C, Silva MP. [Classification and management of hemorrhagic syndromes after surgery with extracorporeal circulation]. Arq Bras Cardiol 1972; 25:287-93. [PMID: 4644464] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023] Open
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