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Lima AF, Moreira FC, Costa IE, Azevedo C, Mar F, Dias L. Tinnitus and Otosclerosis: An Exploratory Study about the Prevalence, Features and Impact in Daily Life. Int Arch Otorhinolaryngol 2021; 26:e390-e395. [PMID: 35846815 PMCID: PMC9282970 DOI: 10.1055/s-0041-1739967] [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: 09/13/2020] [Accepted: 12/07/2020] [Indexed: 11/20/2022] Open
Abstract
Introduction
Tinnitus is experienced by a significant part of the patients suffering from otosclerosis.
Objective
To assess the prevalence of tinnitus in otosclerosis, its main features, and the impact on the daily life.
Methods
Patients diagnosed with otosclerosis in 2019 in a tertiary hospital were enrolled in the study. Demographic data were retrieved and, besides a regular audiometric evaluation, the patients underwent acuphenometry to assess the psychoacoustic measurements (pitch and loudness), and the Tinnitus Handicap Inventory (THI).
Results
In total, 66 patients fulfilled the inclusion criteria, with a female predominance (63.6%; n = 42), and a mean age of 48.7 years. The mean air-bone gap was of 26.3 dB. A total of 72.7% complained of tinnitus; it was mostly unilateral, identified in the low frequencies, namely 500 Hz, with median loudness of 7.5 dB. The median score on the THI score was of 37; most patients had a mild handicap (33.3%, n = 16), followed by those with a severe handicap (22.9%; n = 11). The female gender had a statistically significant association with the presence of tinnitus. The THI scores were higher in middle-aged patients (age groups: 40 to 49 and 50 to 59 years), which was statistically significant. No correlation was found between audiometry results and the prevalence of tinnitus or score on the THI. On the other hand, high-pitched tinnitus, compared to low pitched-tinnitus, was associated with larger air-bone gaps.
Conclusion
The prevalence of tinnitus in our population was in line with the prevalences reported in the literature. It caused a catastrophic handicap in 22.9% of the patients. High-pitched tinnitus was associated with higher handicap. Nonetheless, the existence of tinnitus and its severity were not associated with the degree of hearing loss.
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Affiliation(s)
| | | | | | - Catia Azevedo
- Otorhinolaryngology Service, Hospital de Braga-, Braga, Portugal
| | - Fernando Mar
- Otorhinolaryngology Service, Hospital de Braga-, Braga, Portugal
| | - Luis Dias
- Otorhinolaryngology Service, Hospital de Braga-, Braga, Portugal
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Lima AF, Moreira FC, Costa IE, Dias L. Multiple perforations of the tympanic membrane: what to suspect. BMJ Case Rep 2020; 13:13/12/e235989. [PMID: 33334742 DOI: 10.1136/bcr-2020-235989] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022] Open
Affiliation(s)
- Antonio Fontes Lima
- Otorhinolaryngology and Head and Neck Surgery, Hospital de Braga, Braga, Portugal
| | | | - Isabel Esteves Costa
- Otorhinolaryngology and Head and Neck Surgery, Hospital de Braga, Braga, Portugal
| | - Luis Dias
- Otorhinolaryngology and Head and Neck Surgery, Hospital de Braga, Braga, Portugal
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3
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Costa IE, Sousa Menezes A, Lima AF, Rodrigues B. Extra-skeletal Ewing's sarcoma of the frontal sinus: a rare disorder in pediatric age. BMJ Case Rep 2020; 13:13/5/e232460. [PMID: 32439742 DOI: 10.1136/bcr-2019-232460] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023] Open
Abstract
Paediatric sinonasal tumours comprise numerous aetiologies. Ewing's sarcoma (ES) consists of a malignancy of neuroectodermal origin. This type of sarcoma affects mainly children and adolescents and can assume the skeletal or extra-skeletal form. Primary ES of head and neck is extremely rare, accounting for only 4%-9% of all cases. So far, as much as we know, only a few cases of sinonasal ES have been reported in literature. The authors present a case of a previous healthy 12-year-old girl who presented with a rapidly growing and expansive frontal mass and unilateral nasal obstruction. Immunohistochemical, molecular and cytogenetic analysis of the lesion showed diffuse expression of CD56 and CD99 on tumour cells and a translocation involving chromosome 22q12, confirming ES diagnosis.
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Affiliation(s)
- Isabel Esteves Costa
- Department of Otorhinolaryngology and Head & Neck Surgery, Hospital de Braga, Braga, Portugal
| | - Ana Sousa Menezes
- Department of Otorhinolaryngology and Head & Neck Surgery, Hospital de Braga, Braga, Portugal
| | - Antonio Fontes Lima
- Department of Otorhinolaryngology and Head & Neck Surgery, Hospital de Braga, Braga, Portugal
| | - Berta Rodrigues
- Department of Otorhinolaryngology and Head & Neck Surgery, Hospital de Braga, Braga, Portugal
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Lima AF, May G, Díaz-Colunga J, Pedreiro S, Paiva A, Ferreira L, Enver T, Iborra FJ, Pires das Neves R. Author Correction: Osmotic modulation of chromatin impacts on efficiency and kinetics of cell fate modulation. Sci Rep 2018; 8:11303. [PMID: 30038350 PMCID: PMC6056560 DOI: 10.1038/s41598-018-29328-3] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022] Open
Abstract
A correction to this article has been published and is linked from the HTML and PDF versions of this paper. The error has been fixed in the paper.
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Affiliation(s)
- A F Lima
- UC-Biotech, CNC - Center for Neuroscience and Cell Biology, University of Coimbra, 3060-197, Cantanhede, Portugal.,Faculty of Science and Technology, University Nova of Lisbon (MIT-Portugal PhD Program), 2829-516, Caparica, Portugal
| | - G May
- University College London, Gower Street, London, WC1E 6BT, UK
| | - J Díaz-Colunga
- Centro Nacional de Biotecnología, CSIC. Darwin 3, Campus de Cantoblanco, 28049, Madrid, Spain
| | - S Pedreiro
- Unidade de Gestão Operacional de Citometria, Centro Hospitalar e Universitário de Coimbra, 3000-075, Coimbra, Portugal
| | - A Paiva
- Unidade de Gestão Operacional de Citometria, Centro Hospitalar e Universitário de Coimbra, 3000-075, Coimbra, Portugal.,Coimbra Institute for Clinical and Biomedical Research, Faculty of Medicine,University of Coimbra, 3004-504, Coimbra, Portugal
| | - L Ferreira
- UC-Biotech, CNC - Center for Neuroscience and Cell Biology, University of Coimbra, 3060-197, Cantanhede, Portugal.,Faculty of Medicine, University of Coimbra, 3004-504, Coimbra, Portugal
| | - T Enver
- University College London, Gower Street, London, WC1E 6BT, UK
| | - F J Iborra
- Centro Nacional de Biotecnología, CSIC. Darwin 3, Campus de Cantoblanco, 28049, Madrid, Spain
| | - R Pires das Neves
- UC-Biotech, CNC - Center for Neuroscience and Cell Biology, University of Coimbra, 3060-197, Cantanhede, Portugal. .,Institute for Interdisciplinary Research, University of Coimbra, 3030-789, Coimbra, Portugal.
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5
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Lima AF, May G, Díaz-Colunga J, Pedreiro S, Paiva A, Ferreira L, Enver T, Iborra FJ, Pires das Neves R. Osmotic modulation of chromatin impacts on efficiency and kinetics of cell fate modulation. Sci Rep 2018; 8:7210. [PMID: 29740078 PMCID: PMC5940679 DOI: 10.1038/s41598-018-25517-2] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [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: 09/14/2017] [Accepted: 04/12/2018] [Indexed: 11/23/2022] Open
Abstract
Chromatin structure is a major regulator of transcription and gene expression. Herein we explore the use of osmotic modulation to modify the chromatin structure and reprogram gene expression. In this study we use the extracellular osmotic pressure as a chromatin structure and transcriptional modulator. Hyposmotic modulation promotes chromatin loosening and induces changes in RNA polymerase II (Pol II) activity. The chromatin decondensation opens space for higher amounts of DNA engaged RNA Pol II. Hyposmotic modulation constitutes an alternative route to manipulate cell fate decisions. This technology was tested in model protocols of induced pluripotency and transdifferentiation in cells growing in suspension and adherent to substrates, CD34+ umbilical-cord-blood (UCB), fibroblasts and B-cells. The efficiency and kinetics of these cell fate modulation processes were improved by transient hyposmotic modulation of the cell environment.
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Affiliation(s)
- A F Lima
- UC-Biotech, CNC - Center for Neuroscience and Cell Biology, University of Coimbra, 3060-197, Cantanhede, Portugal.,Faculty of Science and Technology, University Nova of Lisbon (MIT-Portugal PhD Program), 2829-516, Caparica, Portugal
| | - G May
- University College London, Gower Street, London, WC1E 6BT, UK
| | - J Díaz-Colunga
- Centro Nacional de Biotecnología, CSIC. Darwin 3, Campus de Cantoblanco, 28049, Madrid, Spain
| | - S Pedreiro
- Unidade de Gestão Operacional de Citometria, Centro Hospitalar e Universitário de Coimbra, 3000-075, Coimbra, Portugal
| | - A Paiva
- Unidade de Gestão Operacional de Citometria, Centro Hospitalar e Universitário de Coimbra, 3000-075, Coimbra, Portugal.,Coimbra Institute for Clinical and Biomedical Research, Faculty of Medicine,University of Coimbra, 3004-504, Coimbra, Portugal
| | - L Ferreira
- UC-Biotech, CNC - Center for Neuroscience and Cell Biology, University of Coimbra, 3060-197, Cantanhede, Portugal.,Faculty of Medicine, University of Coimbra, 3004-504, Coimbra, Portugal
| | - T Enver
- University College London, Gower Street, London, WC1E 6BT, UK
| | - F J Iborra
- Centro Nacional de Biotecnología, CSIC. Darwin 3, Campus de Cantoblanco, 28049, Madrid, Spain
| | - R Pires das Neves
- UC-Biotech, CNC - Center for Neuroscience and Cell Biology, University of Coimbra, 3060-197, Cantanhede, Portugal. .,Institute for Interdisciplinary Research, University of Coimbra, 3030-789, Coimbra, Portugal.
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Sousa AM, Coutinho WS, Lima AF, Lalic MV. Structural, bonding, and electronic properties of the hexagonal ferroelectric and paraelectric phases of LuMnO3 compound: a density functional theory study. J Chem Phys 2015; 142:074703. [PMID: 25702020 DOI: 10.1063/1.4907787] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
We have investigated the structural, bonding, and electronic properties of both ferroelectric (FE) and paraelectric (PE) phases of the hexagonal LuMnO3 compound using calculations based on density functional theory. The structural properties have been determined by employing the generalized gradient approximation with Perdew-Burke-Ernzerhof and Wu-Cohen parameterization. The bonding and electronic properties have been treated by recently developed modified Becke-Johnson exchange potential, which succeeded to open a band gap for both PE and FE phases, in agreement with experimental predictions. The Bader's topological analysis of electronic density showed that the character of the Lu-O axial bonds changes when the crystal exhibits the PE → FE structural transition. This fact is in agreement with experimental findings. The covalent character of the Lu-O bond significantly increases due to orbital hybridization between the Lu 5dz(2) and O 2pz-states. This bonding mechanism causes the ferroelectricity in the hexagonal LuMnO3 compound.
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Affiliation(s)
- A M Sousa
- Physics Department, Federal University of Sergipe, São Cristóvão 49100-000, Brazil
| | - W S Coutinho
- Physics Department, Federal University of Sergipe, São Cristóvão 49100-000, Brazil
| | - A F Lima
- Physics Department, Federal University of Sergipe, São Cristóvão 49100-000, Brazil
| | - M V Lalic
- Physics Department, Federal University of Sergipe, São Cristóvão 49100-000, Brazil
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Lima AF, Lalic MV. First-principles study of the BiMO4 antisite defect in the Bi12MO20 (M=Si, Ge, Ti) sillenite compounds. J Phys Condens Matter 2013; 25:495505. [PMID: 24214846 DOI: 10.1088/0953-8984/25/49/495505] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/02/2023]
Abstract
Structural, electronic and optical properties of the antisite BiMO4 defect in Bi12MO20 sillenites (BMO, M=Si, Ge, Ti) were investigated using density functional theory. The defect is studied in neutral, positively and negatively charged states. It is demonstrated that within the neutral defect the Bi 6s(2) lone pair is broken and the valence state of the Bi is 4+ (6s(1)). Within the charged defects, the Bi 6s orbital is found to be either full (Bi(3+): 6s(2)) or empty (Bi(5+): 6s(0)). All three charged states introduce energy bands within the BMO gap. By analyzing possible transitions between them we deduced a simple model of functioning of the BiMO4 defect that is able to explain the photochromic and photorefractive effect in sillenites and that reproduces almost all known experimental facts.
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Affiliation(s)
- A F Lima
- Departamento de Física, Universidade Federal de Sergipe, PO Box 353, 49100-000, São Cristóvão, SE, Brazil
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Gomes RSM, Neves R, Cochlin LE, Lima AF, Carvalho R, Korpisalo P, Dragneva G, Paiva A, Ylä-Herttuala S, Clarke K, Carr CA, Ferreira L. 02 Nanoparticles for Simultaneous Cell Tracking & Microrna Delivery. Heart 2012. [DOI: 10.1136/heartjnl-2012-302951.002] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
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Lima AF, Sasaki RT, Araújo LS, Gaglianone LA, Freitas MS, Aguiar FHB, Marchi GM. Effect of Tooth Bleaching on Bond Strength of Enamel-Dentin Cavities Restored With Silorane- and Dimethacrylate-based Materials. Oper Dent 2011; 36:390-6. [DOI: 10.2341/10-332-l] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
Clinical Relevance
Prior bleaching treatment, with both low and high concentrations of bleaching agents, does not affect the push-out bond strength of dimethacrylate- and silorane-based materials to enamel-dentin cavities.
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10
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dos Santos REA, Lima AF, Soares GP, Ambrosano GMB, Marchi GM, Lovadino JR, Aguiar FHB. Effect of preheating resin composite and light-curing units on the microleakage of Class II restorations submitted to thermocycling. Oper Dent 2011; 36:60-5. [PMID: 21488730 DOI: 10.2341/10-226-lr1] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
This in vitro study evaluated microleakage in Class II cavities restored with dental composite and varying light-curing units and the temperature of the composite when subjected to a thermocycling test. Ninety cavities were prepared on the proximal surfaces of bovine teeth and randomly divided according to the light-curing mode (QTH-420 mW/cm2, LED 2nd generation-1100 mW/cm2, or LED 3rd generation-700 mW/cm2) and temperature of the resin composite (23°C, 54°C and 60°C). Following the restorative procedures and thermocycling, the samples were immersed in methylene blue for 12 hours. The samples were ground and the powder prepared for analysis in an absorbance spectrophotometer. All the results were statistically analyzed using the nonparametric tests of Kruskal-Wallis and Dunn (p ≤ 0.05). The results showed that there was no statistical difference between the light-curing modes at a temperature of 23°C. For 54°C, QTH showed a microleakage mean that was significantly lower than those of the LED groups, and for 60°C, QTH had a microleakage mean significantly lower than that of the LED 2nd generation group. There was no statistical difference between the temperatures of the resin composite when LEDs were used. For QTH, 54°C showed statistically lower microleakage than 23°C. The group preheated to 60°C showed no difference when compared to the group heated to 23°C. Preheating the resin composite (54°C and 60°C) did not improve the microleakage means when high-irradiance LED was used; however, it decreased the microleakage means when a QTH with low irradiance was used.
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Affiliation(s)
- R Gredilha
- Laboratório de Diptera, Departamento de Entomologia, Instituto Oswaldo Cruz - FIOCRUZ, Rio de Janeiro, RJ, Brazil.
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12
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Lima AF, Evangelista T, de Carvalho M. Increased creatine kinase and spontaneous activity on electromyography, in amyotrophic lateral sclerosis. Electromyogr Clin Neurophysiol 2003; 43:189-92. [PMID: 12712806] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 03/02/2023]
Abstract
INTRODUCTION Mild to moderate elevation of muscle creatine kinase (CK) is commonly observed in amyotrophic lateral sclerosis (ALS). Although the determinants of increased the CK in ALS remain uncertain, we hypothesize that fasciculations and muscle denervation can be involved by damaging the muscle fibre. PATIENTS AND METHODS We studied 87 ALS patients in whom CK determination was performed. In 47, a standardized EMG investigation was performed. In 22 patients a second CK determination was performed a mean of 5 months later. CK values were compared between different patients arranged in groups as determined by the number of regions with fasciculation as detected on the clinical examination, and the number of muscles with fasciculation or with fibrillation potentials as observed on EMG. RESULTS 43% of our population had an increased CK value. Four out of 5 patients with suspected ALS had an increased CK value. The number of patients with increased CK value was not different between sexes, or between bulbar and spinal-onset patients. CK value was not related with disease duration, and did not change at the second measurement. CK value was not different between the groups studied. CONCLUSION The fasciculations,and the signs of denervation on EMG, are not determinants for high CK values in ALS patients, which are still unknown. Increased CK can be useful in the differential diagnosis of patients with lower motor neuron disorders.
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Affiliation(s)
- A F Lima
- Centro de Estudos Egas Moniz, Faculty of Medicine, University of Lisbon, IMM, Portugal
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13
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Abstract
This article has the objective to show the use of life oral history as methodological framework for qualitative data collection and analysis, aimed to understand the meaning of hemodialysis and the impact of this therapeutic modality of treatment in the patient's life in the Hemodialysis Unity at the University Hospital at the University of São Paulo.
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Affiliation(s)
- A F Lima
- Serviço de Hemodiálise, Hospital Universitário da Universidade de São Paulo
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14
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Abstract
This article makes considerations about the communication in the nursing assistance to the chronic renal patient, submitted to hemodialysis, which treatment is characterized by a frequent relation and sometimes a "closed" professional relation between nurse and patient. The object of this article is to analyse and give examples of the way to use consciently the verbal and nonverbal communication in order to establish a therapeutic interaction of these patients.
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Affiliation(s)
- A B Gullo
- Departamento de Enfermagem Médico-Cirúrgica da EEUSP
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15
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Soares de Moura RS, Leão MC, Castro Resende AC, Moreira CF, Sena KM, Silveira SS, Lima AF, Nunes FR, Mesquita Ferreira AG. Actions of L-NAME and methylene blue on the hypotensive effects of clonidine and rilmenidine in the anesthetized rat. J Cardiovasc Pharmacol 2000; 35:791-5. [PMID: 10813383 DOI: 10.1097/00005344-200005000-00017] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
The antihypertensive mechanism of alpha2-adrenoceptor agonists, such as clonidine and rilmenidine, is not completely elucidated, although it is probably due to reduction of sympathetic tone mediated by stimulation of central alpha2-adrenoceptors. Because activation of alpha2-adrenoceptors on endothelial cells induces release of endothelium-derived relaxing factor (EDRF), we determined whether nitric oxide (NO) release is involved in the antihypertensive action of clonidine and rilmenidine. In chloralose-anesthetised Wistar rats, systolic and diastolic arterial blood pressures were recorded on a polygraph. Intravenous injection of clonidine or rilmenidine (control group) caused a rapid increase of arterial blood pressure. followed by a long-lasting hypotensive effect. The hypotensive effects, estimated as the area enclosed by the decrease in diastolic pressure during the 20 min after clonidine and rilmenidine injections, were 574+/-60 and 410+/-59 mm Hg/min, respectively. The delta decrease in diastolic arterial blood pressure observed 20 min after intravenous injections of clonidine and rilmenidine was 48+/-5 and 34+/-3 mm Hg, respectively. Clonidine and rilmenidine injected 5-10 min after intravenous pretreatment with L-NAME (2 and 1 mg/kg) or methylene blue (10 mg/kg) induced hypotensive effects that were significantly smaller than that observed for the control group. These results suggest that the antihypertensive effects of clonidine and rilmenidine also may be modulated by the NO-cyclic guanosine monophosphate (cGMP) pathway at the level of the central nervous system and/or at the vascular peripheral circulation.
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Affiliation(s)
- R S Soares de Moura
- Departamento de Farmacologia IB, Centro Biomédico, Universidade do Estado do Rio de Janeiro, Brazil.
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Canfield LM, Bulux J, Quan de Serrano J, Rivera C, Lima AF, Lopez CY, Perez R, Khan LK, Harrison GG, Solomons NW. Plasma response to oral beta-carotene in Guatemalan schoolchildren. Am J Clin Nutr 1991; 54:539-47. [PMID: 1877511 DOI: 10.1093/ajcn/54.3.539] [Citation(s) in RCA: 21] [Impact Index Per Article: 0.6] [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: 12/29/2022] Open
Abstract
The response to oral doses of beta-carotene (0 mg, n = 10; 15 mg, n = 20; and 30 mg, n = 21) was studied in 51 Guatemalan children aged 8-15 y, with mean fasting plasma retinol concentrations of 1.72 +/- 0.38 mumol/L. Beta-carotene was delivered with a chocolate drink containing 8.4 g fat. Serial blood sampling was performed at intervals up to 48 h. Circulating retinol concentrations remained relatively constant. The maximum increases in plasma beta-carotene after the 30- and 15-mg doses for all subjects occurred at 24 h and were 0.29 and 0.23 mumol/L, respectively. Time of maximum increase for individuals varied and average maxima over the 48-h period for individuals were 0.13 and 0.26 mumol/L for the 15- and 30-mg-treatment groups, respectively. Increased plasma beta-carotene concentrations were not predicted by recent intake of dietary vitamin A, fasting plasma concentrations, or anthropometric measurements.
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Affiliation(s)
- L M Canfield
- Department of Biochemistry, University of Arizona, Tucson 85721
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Canfield LM, Hopkinson JM, Lima AF, Silva B, Garza C. Vitamin K in colostrum and mature human milk over the lactation period--a cross-sectional study. Am J Clin Nutr 1991; 53:730-5. [PMID: 2000828 DOI: 10.1093/ajcn/53.3.730] [Citation(s) in RCA: 39] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022] Open
Abstract
Vitamin K was quantitated in the milk of four groups of 15 mothers from 1 d to 6 mo postpartum in a cross-sectional study. Concentrations were 7.52 +/- 5.90 and 6.36 +/- 5.32 nmol/L (3.39 +/- 2.66 and 2.87 +/- 2.40 micrograms/L) in colostrum and mature milk, respectively. Differences between colostrum and mature milk or among samples of mature milk collected at 1, 3, and 6 mo were not statistically significant. Because of significantly increased volumes of milk over the lactation period, approximately twice as much vitamin K was delivered in mature milk as in colostrum. Within normal ranges, concentrations of vitamin K in milk were not predicted by dietary intake of vegetables or fat. Vitamin K was correlated with fat in colostrum and was localized in the lipid core of the milk fat globule but was not associated with membranes. Vitamin K in human milk is insufficient to meet recommended intakes for infants aged less than 6 mo. Population and clinical studies are needed to assess the vitamin K status of exclusively breast-fed infants and to evaluate current recommendations.
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Affiliation(s)
- L M Canfield
- Department of Biochemistry, University of Arizona, Tucson 85721
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Abstract
Dictyostelium discoideum synthesizes a 23,000 Mr protein, p23dd-ras, closely related to the mammalian oncogene-encoded protein p21ras. To investigate the subcellular localization of p23dd-ras, conditions were optimized to reduce protein degradation following cell breakage. Subcellular fractionation of D. discoideum showed that p23dd-ras was associated predominantly with the membrane fraction during both vegetative growth and differentiation. In the absence of suitable protease inhibitors considerable amounts of a truncated form of p23dd-ras were recovered in the cytosol fraction, suggesting that intact p23dd-ras is attached to the membrane by a short terminal peptide sequence. Radio-isotope labelling of D. discoideum with myristic acid or palmitic acid in the presence of excess unlabelled acetate resulted in radio-isotope incorporation into a select group of proteins including p23dd-ras. No acyl label appeared in the truncated cytoplasmic form of p23dd-ras when cell breakage was performed in the absence of suitable protease inhibitors, indicating that the acyl group is associated with the short terminal peptide that is cleaved. These data suggest that p23dd-ras, like its mammalian counterpart, is acylated and associated with the plasma membrane. There was no evidence during a 30-minute pulse of methionine for a cytoplasmic precursor to the membrane-bound p23dd-ras, suggesting that the turnover of the presumptive precursor must be much more rapid in D. discoideum than for pro-p21ras in mammalian cells.
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Affiliation(s)
- G Weeks
- Department of Microbiology, University of British Columbia, Vancouver, Canada
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Lima AF, Póvoa F H, Saad EA. [Evaluation of radioimmunoassay in the control of digitalis therapy. Clinical research with beta-methyl-digoxin]. Arq Bras Cardiol 1978; 31:227-32. [PMID: 727974] [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: 12/24/2022] Open
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Lima AF. [Health aspects in Pernambuco]. Rev Bras Enferm 1968; 21:333-43. [PMID: 5197681] [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: 01/14/2023] Open
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