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Gomes F, Ribeiro AC, Sanches GS, Borges HS, Takahashi LAU, Daniel-Ribeiro CT, Tedesco AC, Nascimento JWL, Carvalho LJM. A nanochitosan-D-galactose formulation increases the accumulation of primaquine in the liver. Antimicrob Agents Chemother 2024; 68:e0091523. [PMID: 38517190 PMCID: PMC11064505 DOI: 10.1128/aac.00915-23] [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] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2023] [Accepted: 02/25/2024] [Indexed: 03/23/2024] Open
Abstract
Primaquine is the mainstream antimalarial drug to prevent Plasmodium vivax relapses. However, this drug can induce hemolysis in patients with glucose-6-phosphate dehydrogenase deficiency. Nanostructure formulations of primaquine loaded with D-galactose were used as a strategy to target the drug to the liver and decrease the hemolytic risks. Nanoemulsion (NE-Pq) and nanochitosan (NQ-Pq) formulations of primaquine diphosphate containing D-galactose were prepared and characterized by their physicochemistry properties. Pharmacokinetic and biodistribution studies were conducted using Swiss Webster mice. A single dose of 10 mg/kg of each nanoformulation or free primaquine solution was administered by gavage to the animals, which were killed at 0.5, 1, 2, 4, 8, and 24 hours. Blood samples and tissues were collected, processed, and analyzed by high-performance liquid chromatography. The nanoformulation showed sizes around 200 nm (NE-Pq) and 400 nm (NQ-Pq) and physicochemical stability for over 30 days. Free primaquine solution achieved higher primaquine Cmax in the liver than NE-Pq or NQ-Pq at 0.5 hours. However, the half-life and mean residence time (MRT) of primaquine in the liver were three times higher with the NQ-Pq formulation than with free primaquine, and the volume distribution was four times higher. Conversely, primaquine's half-life, MRT, and volume distribution in the plasma were lower for NQ-Pq than for free primaquine. NE-Pq, on the other hand, accumulated more in the lungs but not in the liver. Galactose-coated primaquine nanochitosan formulation showed increased drug targeting to the liver compared to free primaquine and may represent a promising strategy for a more efficient and safer radical cure for vivax malaria.
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Affiliation(s)
- F. Gomes
- Laboratory of Malaria Research, Oswaldo Cruz Institute (IOC/Fiocruz), Reference Center for Malaria Research, Diagnosis and Training, Rio de Janeiro, Brazil
| | - A. C. Ribeiro
- Laboratory of Malaria Research, Oswaldo Cruz Institute (IOC/Fiocruz), Reference Center for Malaria Research, Diagnosis and Training, Rio de Janeiro, Brazil
- Department of Pharmacology (LaFaCE) - ICB, Federal University of Juiz de Fora (UFJF), Juiz de Fora, Minas Gerais, Brazil
| | - G. S. Sanches
- Laboratory of Malaria Research, Oswaldo Cruz Institute (IOC/Fiocruz), Reference Center for Malaria Research, Diagnosis and Training, Rio de Janeiro, Brazil
| | - H. S. Borges
- Department of Chemistry, Center of Nanotechnology and Tissue Engineering - Photobiology and Photomedicine Research Group, Faculty of Philosophy, Sciences and Letters, University of São Paulo, Ribeirão Preto, São Paulo, Brazil
| | - L. A. U. Takahashi
- Department of Chemistry, Center of Nanotechnology and Tissue Engineering - Photobiology and Photomedicine Research Group, Faculty of Philosophy, Sciences and Letters, University of São Paulo, Ribeirão Preto, São Paulo, Brazil
| | - C. T. Daniel-Ribeiro
- Laboratory of Malaria Research, Oswaldo Cruz Institute (IOC/Fiocruz), Reference Center for Malaria Research, Diagnosis and Training, Rio de Janeiro, Brazil
| | - A. C. Tedesco
- Department of Chemistry, Center of Nanotechnology and Tissue Engineering - Photobiology and Photomedicine Research Group, Faculty of Philosophy, Sciences and Letters, University of São Paulo, Ribeirão Preto, São Paulo, Brazil
| | - J. W. L. Nascimento
- Department of Pharmacology (LaFaCE) - ICB, Federal University of Juiz de Fora (UFJF), Juiz de Fora, Minas Gerais, Brazil
| | - L. J. M. Carvalho
- Laboratory of Malaria Research, Oswaldo Cruz Institute (IOC/Fiocruz), Reference Center for Malaria Research, Diagnosis and Training, Rio de Janeiro, Brazil
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Palhão MP, Ribeiro AC, Martins AB, Guimarães CRB, Alvarez RD, Seber MF, Fernandes CAC, Neves JP, Viana JHM. Early resynchronization of non-pregnant beef cows based in corpus luteum blood flow evaluation 21 days after Timed-AI. Theriogenology 2020; 146:26-30. [PMID: 32036057 DOI: 10.1016/j.theriogenology.2020.01.064] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2019] [Revised: 12/05/2019] [Accepted: 01/28/2020] [Indexed: 12/11/2022]
Abstract
The study aimed to verify whether a hormone protocol started at Day 13 (D13) after Timed Artificial Insemination (TAI) influences the conception rate. Nelore cows (primiparous and multiparous) from two commercial beef farms (n = 1,431) were first TAI (D0). Timed AI was performed in lots (TAI Lots) ranging from 187 to 346 cows. On D13, regarding the TAI lot, cows were assigned for either receiving (Resynch group, n = 1,002) or not (Control group, a subset of approximately 30%, n = 429) another hormone protocol for resynchronization. The same hormone protocol was used for the first TAI and for the resynchronization, except for 1 mg instead of 2 mg of estradiol benzoate (EB) at the begging of the protocol. Eight days later (D21), the Resynch group was checked for corpus luteum blood flow by color Doppler ultrasonography, and in those detected as non-pregnant, the protocol was completed and a 2nd TAI was performed at D23. Pregnancy diagnosis was later (D30) performed by B-mode ultrasonography in the control group and confirmed in the presumptive pregnant cows from the 1st TAI of the Resynch group. The remaining cows were checked for pregnancy 30 days after the 2nd TAI (experimental Day 53). The statistical model to explain conception rate considered the effects of Group (Control or Resynch), Farm, Parity (primiparous or multiparous), Sire, Technician (who perform AI), TAI Lot and pertinent interactions (Group*Parity, Group*Farm and Group*TAI Lot). The statistical analyses of the model were performed using the Proc Glimmix (SAS virtual University Edition). The conception rate for the 1st TAI was similar (P > 0.4) between Control (50.3%, 216/429) and Resynch group (52.6%, 527/1002). The positive predictive diagnostic on D21 showed high relation with PD30 (90.7%, 527/581). In Resynch group, non-pregnant cows (n = 421, 1002 minus 581) were re-inseminated. The conception rate of the 2nd TAI (42.8%, 180/421) was affected (P < 0.002) by side effects of the Farm (48.5 vs. 33.1%) and Parity (51.2 vs. 40.3%, for multiparous vs. primiparous, p < 0.001). Nevertheless, after the 2 TAIs of the Resynch group, the cumulative conception rate was 70.5% (707/1002). In conclusion, the early resynchronization of cows with a low (1 mg) EB dose and progesterone device at D13 after TAI can be used as a strategy to reduce conception interval in beef cattle, and thus to increase the number of pregnant cows from artificial insemination after the breeding season.
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Affiliation(s)
- M P Palhão
- University José do Rosário Vellano - UNIFENAS, Alfenas, MG, 37130-000, Brazil.
| | - A C Ribeiro
- University José do Rosário Vellano - UNIFENAS, Alfenas, MG, 37130-000, Brazil
| | - A B Martins
- University José do Rosário Vellano - UNIFENAS, Alfenas, MG, 37130-000, Brazil
| | - C R B Guimarães
- University José do Rosário Vellano - UNIFENAS, Alfenas, MG, 37130-000, Brazil
| | - R D Alvarez
- Veterinary Practitioner, Porto Esperidião, MT, 78240-000, Brazil
| | - M F Seber
- University José do Rosário Vellano - UNIFENAS, Alfenas, MG, 37130-000, Brazil
| | - C A C Fernandes
- University José do Rosário Vellano - UNIFENAS, Alfenas, MG, 37130-000, Brazil
| | - J P Neves
- University José do Rosário Vellano - UNIFENAS, Alfenas, MG, 37130-000, Brazil
| | - J H M Viana
- University José do Rosário Vellano - UNIFENAS, Alfenas, MG, 37130-000, Brazil; Embrapa Recursos Genéticos e Biotecnologia, Brasília, DF, 70770-917, Brazil
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Gadelha BQ, Ribeiro AC, Aguiar VM, Mello-Patiu CA. Edge effects on the blowfly fauna (Diptera, Calliphoridae) of the Tijuca National Park, Rio de Janeiro, Brazil. BRAZ J BIOL 2015; 75:999-1007. [PMID: 26675918 DOI: 10.1590/1519-6984.05614] [Citation(s) in RCA: 11] [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] [Received: 04/10/2014] [Accepted: 06/26/2014] [Indexed: 11/22/2022] Open
Abstract
In this contribution we examine the diversity, abundance and species richness of Calliphoridae in the Tijuca National Park, Rio de Janeiro, RJ. Specimens were collected monthly between September 2009 and August 2010, using sardines as bait, in three points: A, on the forest edge (22°56'846"S 43°17'496"W), B, 700 m from it (22°57'073"S 43°17'832"W) and C, 1,200 m into the forest (22°57'321"S 43°18'031"W), evaluating the indicator species at each point and the anthropogenic influences and abiotic factors that determine species distribution. A total of 16,364 Calliphoridae were collected and 17 species were identified. Species abundance was strongly positively correlated with temperature. The greatest number of flies was collected at A, but in this point, diversity was lower and most individuals collected belonged to the dominant species. Point C, conversely, had the lower abundance and the highest diversity. Chrysomya megacephala, an urban and synanthropic species, was dominant at point A, whereas Laneela nigripes and Mesembrinella peregrina, typically forest species, were considered indicators at points B and C, respectively, showing that the anthropogenic influence is more intense at the forest edge.
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Affiliation(s)
- B Q Gadelha
- Departamento de Microbiologia e Parasitologia, Universidade Federal do Estado do Rio de Janeiro, Rio de Janeiro, RJ, Brazil
| | - A C Ribeiro
- Departamento de Microbiologia e Parasitologia, Universidade Federal do Estado do Rio de Janeiro, Rio de Janeiro, RJ, Brazil
| | - V M Aguiar
- Departamento de Microbiologia e Parasitologia, Universidade Federal do Estado do Rio de Janeiro, Rio de Janeiro, RJ, Brazil
| | - C A Mello-Patiu
- Museu Nacional, Universidade Federal do Rio de Janeiro, Rio de Janeiro, RJ, Brazil
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Calandrini CA, Ribeiro AC, Gonnelli AC, Ota-Tsuzuki C, Rangel LP, Saba-Chujfi E, Mayer MPA. Microbial composition of atherosclerotic plaques. Oral Dis 2015; 20:e128-34. [PMID: 24188425 DOI: 10.1111/odi.12205] [Citation(s) in RCA: 50] [Impact Index Per Article: 5.6] [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: 10/16/2012] [Revised: 10/08/2013] [Accepted: 10/14/2013] [Indexed: 12/20/2022]
Abstract
OBJECTIVE The association of infections such as periodontitis with atherosclerotic diseases is well documented. In spite of the high diversity of the human oral microbiota, and its close contact with the circulatory system, few oral species were detected in atherosclerotic plaques. Thus, we attempted to evaluate the microbial diversity of atherosclerotic plaques from patients with different periodontal conditions, submitted to endarterectomy by a broad-range microbial method. MATERIALS AND METHODS Patients indicated for aorta endarterectomy due to myocardial infarction were recruited for periodontal clinical examination. The microbial diversity of atherosclerotic plaques (n = 35) was evaluated by sequence analysis of bacterial 16S rRNA libraries. RESULTS Bacterial DNA was detected in 12 endarterectomy specimens (34.3%). Twenty-three bacterial species/phylotypes were identified. Proteobacteria and Firmicutes comprised 78.3% and 21.7% of the identified taxa, respectively. Fifteen (60.9%) phylotypes were reported as yet uncultivable or as yet uncharacterized species. Two uncultured phylotypes were previously detected in the human mouth. The periodontopathogen Aggregatibacter actinomycetemcomitans was detected in seven samples (20%), followed by Pseudomonas species. There was no association between periodontal parameters and detection of A. actinomycetemcomitans or other phylotypes in atherosclerotic plaques. CONCLUSION Our results suggest a role of the oral microbiota in the development of inflammation in atherogenesis, particularly of A. actinomycetemcomitans.
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Affiliation(s)
- C A Calandrini
- Department of Microbiology, Institute of Biomedical Sciences, University of São Paulo, São Paulo, SP, Brazil; Department of Periodontology, São Leopoldo Mandic University, Campinas, SP, Brazil
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Ferraz A, Zhang J, Sebastião PJ, Ribeiro AC, Dong RY. Proton and deuterium nuclear spin relaxation study of the SmA and SmC* phases of BP8Cl-d17 : a self-consistent analysis. Magn Reson Chem 2014; 52:546-555. [PMID: 25132369 DOI: 10.1002/mrc.4107] [Citation(s) in RCA: 3] [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] [Subscribe] [Scholar Register] [Received: 03/18/2014] [Revised: 06/01/2014] [Accepted: 06/18/2014] [Indexed: 06/03/2023]
Abstract
A self-consistent analysis of proton and deuterium nuclear spin relaxation times in the smectic phases of a partially deuterated smectogen is presented here. Proton spin-lattice relaxation times T(1Z) were measured as a function of Larmor frequency over a range of 1 kHz to 300 MHz at selected temperatures. Deuterium spin relaxation times T(1Z) and T(1Q) were measured as a function of temperature at two different magnetic fields in the smectic A phase. The deuterium data provide dynamic parameters such as rotational diffusion constants and internal jump rates as well as the nematic order parameter S. The proton data are analyzed using a number of relaxation mechanisms, one of which is the molecular reorientation. It is found helpful in these latter analyses to use the nematic order parameter and to fix the contribution from molecular reorientations determined by the deuterium spin relaxation. The fits to the proton T(1) frequency and temperature dispersions by the remaining relaxation mechanisms such as layer undulations and translational self-diffusion will be discussed for the smectic A and chiral smectic C phases.
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Affiliation(s)
- A Ferraz
- Department of Physics, Instituto Superior Técnico, Universidade de Lisboa, Av. Rovisco Pais, 1049-001 Lisbon, Portugal; Centro de Física da Matéria Condensada, Av. Prof. Gama Pinto 2, 1649-003 Lisbon, Portugal
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Cruz C, Sebastião PJ, Figueirinhas J, Ribeiro AC, Nguyen HT, Destrade C, Noack F. NMR Study of Molecular Dynamics in a D ho Columnar Mesophase. ACTA ACUST UNITED AC 2014. [DOI: 10.1515/zna-1998-10-1104] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
Abstract
In this paper we report the first molecular dynamics study combining fast field-cycling and conven-tional NMR techniques in a thermotropic liquid crystal of discotic molecules exhibiting an ordered columnar hexagonal mesophase. Using the association of these techniques we obtained proton T1 data over a very large domain of Larmor frequencies (ω/2π from 500 Hz to 85 MHz). The proton spin-lattice relaxation results were analysed considering the structure of the mesophase and the types of movements which are expected to influence significantly the relaxation rate, namely local molecu-lar rotational reorientations, inter-columnar self-diffusion and collective movements corresponding to bending and compression of the columns. We verified that these mechanisms dominate the relaxation respectively for high, medium and low Larmor frequencies.
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Affiliation(s)
- C. Cruz
- Centro de Física da Materia Condensada, Av. Prof. Gama Pinto 2, 1699 Lisboa Codex, Portugal
- Instituto Superior Tecnico, Departamento de Física, Av. Rovisco Pais, 1096 Lisboa Codex, Portugal
| | - P. J. Sebastião
- Centro de Física da Materia Condensada, Av. Prof. Gama Pinto 2, 1699 Lisboa Codex, Portugal
- Instituto Superior Tecnico, Departamento de Física, Av. Rovisco Pais, 1096 Lisboa Codex, Portugal
| | - J. Figueirinhas
- Centro de Física da Materia Condensada, Av. Prof. Gama Pinto 2, 1699 Lisboa Codex, Portugal
- Instituto Superior Tecnico, Departamento de Física, Av. Rovisco Pais, 1096 Lisboa Codex, Portugal
| | - A. C. Ribeiro
- Centro de Física da Materia Condensada, Av. Prof. Gama Pinto 2, 1699 Lisboa Codex, Portugal
- Instituto Superior Tecnico, Departamento de Física, Av. Rovisco Pais, 1096 Lisboa Codex, Portugal
| | - H. T. Nguyen
- Centre de Recherche Paul Pascal, Domaine Universitaire, 33405 Talence, France
| | - C. Destrade
- Centre de Recherche Paul Pascal, Domaine Universitaire, 33405 Talence, France
| | - F. Noack
- Physikalisches Institut der Universität Stuttgart, Pfaffenwaldring 57, D-70550 Stuttgart
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Aikawa NE, Trudes G, Campos LMA, Pereira RMR, Moraes JCB, Ribeiro AC, Miraglia J, Timenetsky MDCS, Bonfa E, Silva CA. Immunogenicity and safety of two doses of a non-adjuvanted influenza A H1N1/2009 vaccine in young autoimmune rheumatic diseases patients. Lupus 2013; 22:1394-8. [DOI: 10.1177/0961203313505926] [Citation(s) in RCA: 15] [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: 11/15/2022]
Abstract
Objectives The aim of this study was to evaluate the immunogenicity and safety of the influenza A H1N1/2009 vaccine in children under 9 years old with autoimmune rheumatic diseases (ARD). Methods Thirty-eight ARD patients and 11 healthy children received two doses of non-adjuvanted influenza A/California/7/2009 (H1N1) virus-like vaccine. Subjects were evaluated before and 21 days after vaccination. Seroprotection (SP) and seroconversion (SC) rates, geometric mean titers (GMT) and factor increases (FI) in GMT were calculated. Results Mean ages were comparable between patients and controls. Pre-vaccination SP and GMT were similar in patients and controls ( p > 0.05). Three weeks after immunization, SP (81.6% vs. 81.8%, p = 1.0), SC (81.6% vs. 90.9%, p = 0.66), GMT (151.5 vs. 282.1, p = 0.26) and the FI in GMT (16.7 vs. 36.3, p = 0.23) were similar in patients and controls, with both groups achieving an adequate response, according to the European Medicines Agency and Food and Drug Administration standards. Analysis of the possible factors influencing SC showed no difference in demographic data, leukocyte/lymphocyte counts or immunosuppressant use between seroconverted and non-seroconverted patients ( p > 0.05). The vaccine demonstrated a satisfactory safety profile in this population. Conclusions Two doses of influenza A H1N1/2009 vaccination induced an effective antibody response and caused adverse events in rare instances, suggesting this vaccine is appropriate and can be recommended for this age group.
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Affiliation(s)
- NE Aikawa
- Pediatric Rheumatology Unit
- Division of Rheumatology, University of Sao Paulo, Brazil
| | | | | | - RMR Pereira
- Division of Rheumatology, University of Sao Paulo, Brazil
| | - JCB Moraes
- Division of Rheumatology, University of Sao Paulo, Brazil
| | - AC Ribeiro
- Division of Rheumatology, University of Sao Paulo, Brazil
| | | | | | - E Bonfa
- Division of Rheumatology, University of Sao Paulo, Brazil
| | - CA Silva
- Pediatric Rheumatology Unit
- Division of Rheumatology, University of Sao Paulo, Brazil
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Santos SG, Lamghari M, Almeida CR, Oliveira MI, Neves N, Ribeiro AC, Barbosa JN, Barros R, Maciel J, Martins MCL, Gonçalves RM, Barbosa MA. Adsorbed fibrinogen leads to improved bone regeneration and correlates with differences in the systemic immune response. Acta Biomater 2013; 9:7209-17. [PMID: 23571000 DOI: 10.1016/j.actbio.2013.04.008] [Citation(s) in RCA: 45] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2012] [Revised: 03/21/2013] [Accepted: 04/02/2013] [Indexed: 12/25/2022]
Abstract
Designing new biomaterials that can modulate the inflammatory response instead of attempting just to reduce it constitutes a paradigm change in regenerative medicine. This work aimed to investigate the capacity of an immunomodulatory biomaterial to enhance bone regeneration. For that purpose we incorporated a molecule with well-established pro-inflammatory and pro-healing roles, fibrinogen, in chitosan scaffolds. Two different incorporation strategies were tested, leading to concentrations of 0.54±0.10mg fibrinogen g(-1) scaffold immediately upon adsorption (Fg-Sol), and 0.34±0.04mg fibrinogen g(-1) scaffold after washing (Fg-Ads). These materials were implanted in a critical size bone defect in rats. At two months post-implantation the extent of bone regeneration was examined by histology and the systemic immune response triggered was evaluated by determining the percentages of myeloid cells, T and B lymphocytes in the draining lymph nodes. The results obtained indicate that the fibrinogen incorporation strategy conditioned the osteogenic capacity of biomaterials. Fg-Ads scaffolds led to more bone formation, and the presence of Fg stimulated angiogenesis. Furthermore, animals implanted with Fg-Ads scaffolds showed significant increases in the percentages of B lymphocytes and myeloid cells in the draining lymph nodes, while levels of T lymphocytes were not significantly different. Finally, a significant increase in TGF-β1 was detected in the plasma of animals implanted with Fg-Ads. Taken together the results presented suggest a potential correlation between the elicited immune response and biomaterial osteogenic performance.
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Affiliation(s)
- S G Santos
- Instituto de Engenharia Biomédica, Universidade do Porto, Rua do Campo Alegre 823, 4150-180 Porto, Portugal.
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Aikawa NE, Campos LMA, Goldenstein-Schainberg C, Saad CGS, Ribeiro AC, Bueno C, Precioso AR, Timenetsky M, Silva CAA, Bonfá E. Effective seroconversion and safety following the pandemic influenza vaccination (anti-H1N1) in patients with juvenile idiopathic arthritis. Scand J Rheumatol 2012; 42:34-40. [DOI: 10.3109/03009742.2012.709272] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
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Abstract
Archaea present distinct features from bacteria and eukaryotes, and thus constitute one of the branches of the phylogenetic tree of life. Members of this domain colonize distinct niches in the human body, arranged in complex communities, especially in the intestines and the oral cavity. The diversity of archaea within these niches is limited to a few phylotypes, constituted in particular by methane-producing archaeal organisms. Although they are possibly symbionts, methanogens may play a role in the establishment of mucosal diseases by favouring the growth of certain bacterial groups.
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Affiliation(s)
- F Matarazzo
- Department of Microbiology, Institute of Biomedical Sciences, University of São Paulo, São Paulo, Brazil
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Steiner-Oliveira C, Aranha ACC, Ribeiro AC, Mayer MP, Eduardo CP. In vivo randomized antimicrobial effect of the Photodynamic Therapy on deciduous carious dentin. Med Oral Patol Oral Cir Bucal 2012. [DOI: 10.4317/medoral.17643720] [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: 11/05/2022] Open
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Abstract
A theory is put forward that emphasises differences in neuronal responses to fluctuations in steroid hormone levels compared to constant hormone levels. We propose that neuronal functions that regulate gonadotrophin release from the anterior pituitary tend to be more sensitive to rapid increases in the levels of oestrogens than they are to constant oestrogen levels. By contrast, neurones that control certain behavioral functions are affected just as well by constant oestrogen levels as by positively accelerating levels of oestrogen. In addition to providing examples of data from recent experiments that examine actions of the long-term effects of oestrogen on mouse behaviour, we illustrate the behavioural effects of microinjections of adeno-associated viral vectors of small interfering RNA directed against the mRNA for oestrogen receptor-alpha (ERalpha). This manipulation provides for a long-term loss of ERalpha function in a neuranatomically specific manner. The theoretical distinction between temporal features of oestrogen sensitivity of neuroendocrine versus behavioural function is not absolute, but is intended to stimulate new experimentation that examines temporal features of oestrogen administration.
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Affiliation(s)
- D W Pfaff
- Laboratory of Neurobiology and Behavior, The Rockefeller University, New York, NY 10065, USA
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Souza JMG, Torres CAA, Ribeiro SDA, Ribeiro AC, Becalete L, Rigo AG, Silva WJ, Facó O, Fonseca JF. 447 INDUCTION OF ESTRUS IN ANGLO-NUBIAN GOATS IN THE TRANSITION SEASON WITH SHORT-TERM PROGESTAGEN PROTOCOLS WITH OR WITHOUT eCG ADMINISTRATION. Reprod Fertil Dev 2010. [DOI: 10.1071/rdv22n1ab447] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
Abstract
Synchronized estrus can be induced by different hormonal protocols including prostaglandin, progestagens, and gonadotrophins. Equine chorionic gonadotrophin is a FSH-like hormone produced by pregnant mares that can evoke antibody formation in goats. Thus, if possible, restriction of its use should be considered. The aim of this study was to investigate the possibility to omit the administration of eCG to induce estrus in Anglo- Nubian goats during the transition season. This study was done in February of 2009 in Espírito Santo do Pinhal/SP (22°57′S latitude and 46°58′W longitude), Brazil. The local breeding season extends from March to June. A total of 10 nulliparous and 10 pluriparous Anglo-Nubian goats were equally assigned into 2 treatments with (T1) or without (T2) 200 IU eCG (Novormon 5000®, Intervet Schering Plough Animal Health, São Paulo, Brazil) i.m. administration 24 h before sponge removal. All goats received (Day 0) intravaginal sponges (60 mg of MAP; Progespon®, Intervet Schering Plough Animal Health) and 50 mg d-cloprostenol (Ciosin®, Intervet Schering Plough Animal Health) i.m. Estrous behavior and transrectal ultrasonography (5-MHz transducer; Aloka SSD 500®, Tokyo, Japan) were performed at 12-h intervals (0600 and 1800h) until 96 h after sponge removal. Statistical analysis was performed using all tests at the 95% confidence interval with a SAEG® program (Funarbe, Viçosa, Brazil). Estrous response was 100% (10/10) for T1 and 70% (7/10) for T2 (P > 0.05). All animals that were detected in estrus ovulated, and none of the 3 that did not show estrus ovulated. The interval from sponge removal to estrous onset (h) was 36.0 ± 9.8 (T1) and 34.8 ± 10.5 (T2), whereas its duration (h) was 27.4 ± 14.5 (T1) and 32.6 ± 12.7 (P > 0.05). The interval from sponge removal to ovulation (h) was 67.0 ± 8.0 (T1) and 73.9 ± 6.4 (T2). Also, the interval from estrous onset to ovulation (h) was 25.2 ± 8.85 (T1) and 30.9 ± 6.4 (T2). No difference (P > 0.05) was observed in the number of ovulations for T1 (1.2 ± 0.4) and T2 (1.4 ± 0.5). The diameter of the ovulatory follicle (mm) was similar (P > 0.05) for T1 (6.7 ± 0.6) andT2 (6.5 ± 0.6) (P > 0.05). Further studies should be done to consider if the use of eCG is necessary in the transition season for Anglo-Nubian goats.
Financial support: Embrapa Goats and Sheep; Capritec; CNPq; Intervet Schering Plough Animal Health; Fapemig.
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Filip D, Cruz C, Sebastião PJ, Cardoso M, Ribeiro AC, Vilfan M, Meyer T, Kouwer PHJ, Mehl GH. Phase structure and molecular dynamics of liquid-crystalline side-on organosiloxane tetrapodes. Phys Rev E Stat Nonlin Soft Matter Phys 2010; 81:011702. [PMID: 20365386 DOI: 10.1103/physreve.81.011702] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/07/2009] [Indexed: 05/29/2023]
Abstract
X-ray diffraction and proton NMR relaxation measurements were carried out on two liquid-crystalline organosiloxane tetrapodes with side-on mesogenic groups, exhibiting nematic and smectic- C phases, and on a monomeric analog. Packing models for the mesophases exhibited by these systems are proposed on the basis of x-ray diffraction data. As a consequence of microsegregation, the aromatic cores are packed in between two sublayers formed by a mixture of interdigitated aliphatic and siloxane chains. The mixed sublayers are characteristic for the tetrapodes with side-on mesogenic groups presented in this work and have not been observed in tetrapodes with terminally attached mesogens. The tilt angle in the smectic- C phase is found very large, i.e., approximately 61 degrees -62 degrees . Notably, smectic- C clusters are present also in the whole temperature range of the nematic phase. NMR relaxometry yields T(1)-1 dispersions clearly different from those of conventional calamitics. The influence of molecular tendency to form interdigitated structures is evidenced by frequency-dependent relaxation rate in the isotropic phase-indicating the presence of ordered clusters far above the phase transition-and by the diminished role of molecular self-diffusion in ordered phases. Nematiclike director fluctuations are the dominating relaxation mechanism whereas the translational displacements are strongly hindered by the interdigitation of dendrimer arms.
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Affiliation(s)
- D Filip
- Centro de Física da Matéria Condensada, Universidade de Lisboa, Lisboa, Portugal
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15
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Cruz C, Figueirinhas JL, Filip D, Feio G, Ribeiro AC, Frère Y, Meyer T, Mehl GH. Biaxial nematic order and phase behavior studies in an organosiloxane tetrapode using complementary deuterium NMR experiments. Phys Rev E Stat Nonlin Soft Matter Phys 2008; 78:051702. [PMID: 19113138 DOI: 10.1103/physreve.78.051702] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/10/2006] [Revised: 07/10/2008] [Indexed: 05/27/2023]
Abstract
The biaxial nematic phase was recently observed in different thermotropic liquid crystals, namely bent-core compounds, side-chain polymers, bent-core dimers, and organosiloxane tetrapodes. In this work, a series of experiments with a nematic organosiloxane tetrapode where nuclear magnetic resonance (NMR) spectra are collected while the sample is continuously rotating around an axis perpendicular to the magnetic field, are discussed in conjunction with the analysis of a deuterium NMR experiment on the same system reported earlier. The sample used is a mixture of a deuterated probe with the tetrapode. The mixture exhibits a nematic range between -40 degrees C and 37 degrees C. The results of the two independent, but complementary deuterium NMR experiments confirm the existence of a biaxial nematic phase for temperatures below 0 degrees C with high values of the asymmetry parameter at low temperatures. The presence of slow movements of the tetrapode mesogenic units in the low-temperature regime could also be detected through the analysis of the NMR spectra. Simulations indicate that these movements are mainly slow molecular reorientations of the mesogenic units associated with the presence of collective modes in the nematic phases of this compound. In the case of tetrapodes, recent investigations attribute the origin of biaxiality to the hindering of reorientations of the laterally attached mesogenic units which constitute the tetrapode. This study relates the molecular movements with the nematic biaxial ordering of the system.
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Affiliation(s)
- C Cruz
- CFMC-UL, Av. Prof. Gama Pinto 2, 1649-003 Lisboa, Portugal
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16
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Filip D, Cruz C, Sebastião PJ, Ribeiro AC, Vilfan M, Meyer T, Kouwer PHJ, Mehl GH. Structure and molecular dynamics of the mesophases exhibited by an organosiloxane tetrapode with strong polar terminal groups. Phys Rev E Stat Nonlin Soft Matter Phys 2007; 75:011704. [PMID: 17358170 DOI: 10.1103/physreve.75.011704] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/27/2006] [Indexed: 05/14/2023]
Abstract
The polymorphism of a new organosiloxane tetrapode compound with cyano terminal polar groups was characterized by means of polarizing optical microscopy and x-ray diffraction. The compound exhibits smectic- A and smectic- C phases with a partial bilayer arrangement due to a certain degree of head-to-head association of the mesogenic units through their cyano end groups. On the basis of x-ray diffraction results, evidencing the microsegregation of polyphilic molecules, packing models for the smectic- A and smectic- C phases are proposed. A high degree of smectic positional order and a relatively low value of the tilt angle in the smectic- C phase are indicated. Molecular dynamics of the studied compound was investigated by means of proton NMR relaxometry. The frequency dispersions of the spin-lattice relaxation time (T1) show that the relaxation is induced by three rotational modes of individual dendrimer arms with frequencies between 10;{6} and 10;{9}Hz . In the smectic phases, the effect of individual rotations is overwhelmed by a well expressed contribution of layer undulations at Larmor frequencies below approximately 10MHz . The appearance of this relaxation mechanism over the frequency range of three decades is so far unique in the case of thermotropic liquid crystals. The analysis of the layer undulations contribution supports the microsegregation model of the smectic phases by revealing a slowing-down of translational diffusion and the lack of interactions among the sublayers formed by the mesogenic groups.
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Affiliation(s)
- D Filip
- Centro de Física da Matéria Condensada, Av. Prof. Gama Pinto 2, 1649-003 Lisbon, Portugal
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17
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Zhang J, Ferraz A, Ribeiro AC, Sebasti O PJ, Dong RY. Deuterium nuclear-magnetic-resonance study of a chiral smectic-C{*} phase. Phys Rev E Stat Nonlin Soft Matter Phys 2006; 74:061704. [PMID: 17280081 DOI: 10.1103/physreve.74.061704] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/03/2006] [Indexed: 05/13/2023]
Abstract
This study reports deuterium nuclear-magnetic-resonance (NMR) spectra collected at 61.4MHz in the chiral smectic- C phase of liquid crystal 4{'}(octyloxy)-d{17} biphenyl-4- yl2 -chloro-3-methylpentanoate (BP8Cl). By using a goniometer probe, the oriented sample was rotated to collect spectra at different rotation (theta) angles. These spectra were simulated to gain information on solitonlike distortions in the helical superstructure. The Landau theory was adopted to study the distortion of the helix by the NMR magnetic field. Deuterium two-dimensional exchange experiments were also used on the aligned sample at theta=15 degrees to obtain dynamic parameters through the spectral simulation. The interlayer diffusion constants in the SmC{*} phase were estimated from a proton T(1) dispersion study. The pitch length of BP8Cl is estimated to be circa 2-3 microns at one temperature.
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Affiliation(s)
- J Zhang
- Department of Physics and Astronomy, University of Manitoba, Winnipeg, Manitoba, Canada R3T 2N2
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Affiliation(s)
- A. Ferraz
- a IST-UTL, Av. Rovisco Pais, 1096 Lisboa Codex and CFMC-UL , Av. Prof. Gama Pinto, n[ddot] 2, 1699 , Lisboa Codex , Portugal
| | - A. C. Ribeiro
- a IST-UTL, Av. Rovisco Pais, 1096 Lisboa Codex and CFMC-UL , Av. Prof. Gama Pinto, n[ddot] 2, 1699 , Lisboa Codex , Portugal
| | - H. T. Nguyen
- b Centre de Recherche Paul Pascal, Domaine Universitaire , 33405 , Talence , France
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Guillon D, Heinrich B, Ribeiro AC, Cruz C, Nguyen HT. Thermotropic Lamellar-to-Columnar Phase Transition Exhibited by a Biforked Compound. ACTA ACUST UNITED AC 2006. [DOI: 10.1080/10587259808047105] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
Affiliation(s)
- D. Guillon
- a Institut de Physiquet et de Chimie des Matériaux de Strasbourg , Groupe des Matériaux Organiques, 23, rue du Loess, F-67037 , Strasbourg Cedex , France
| | - B. Heinrich
- a Institut de Physiquet et de Chimie des Matériaux de Strasbourg , Groupe des Matériaux Organiques, 23, rue du Loess, F-67037 , Strasbourg Cedex , France
| | - A. C. Ribeiro
- a Institut de Physiquet et de Chimie des Matériaux de Strasbourg , Groupe des Matériaux Organiques, 23, rue du Loess, F-67037 , Strasbourg Cedex , France
- b Centro de Fisica da Matéria Condensada , Av. Prof. Gama Pinto 2, 1699 , Lisboa Codex , Portugal
| | - C. Cruz
- b Centro de Fisica da Matéria Condensada , Av. Prof. Gama Pinto 2, 1699 , Lisboa Codex , Portugal
| | - H. T. Nguyen
- c Centre de Recherche Paul Pascal , Avenue A. Schweitzer, 33 600 , Pessac , France
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Cruz C, Ribeiro AC, Biforked. Molecular Dynamics in Columnar Phases Exhibited by Compounds of Discotic and Biforked Molecules, A Comparative Study from NMR Results. ACTA ACUST UNITED AC 2006. [DOI: 10.1080/10587259908047502] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
Affiliation(s)
- C. Cruz
- a IST-UTL, Av. Rovisco Pais , 1096 Lisboa Codex, Portugal and CFMC-UL, Av. Prof. Gama Pinto, 2, 1699 , Lisboa Codex , Portugal
| | - A. C. Ribeiro
- a IST-UTL, Av. Rovisco Pais , 1096 Lisboa Codex, Portugal and CFMC-UL, Av. Prof. Gama Pinto, 2, 1699 , Lisboa Codex , Portugal
| | - Biforked
- a IST-UTL, Av. Rovisco Pais , 1096 Lisboa Codex, Portugal and CFMC-UL, Av. Prof. Gama Pinto, 2, 1699 , Lisboa Codex , Portugal
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Almeida PL, Cidade MT, Godinho MH, Ribeiro AC, Figueirinhas JL. Light Scattering Studies in Cellulose Derivative Based PDLC Type Cells. ACTA ACUST UNITED AC 2006. [DOI: 10.1080/10587250108035569] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
Affiliation(s)
- P. L. Almeida
- a Dept. Ciěncia dos Materiais and CENIMAT , FCT/UNL , Quinta da Torre, 2825-114 , Monte de Caparica , Portugal
| | - M. T. Cidade
- a Dept. Ciěncia dos Materiais and CENIMAT , FCT/UNL , Quinta da Torre, 2825-114 , Monte de Caparica , Portugal
| | - M. H. Godinho
- a Dept. Ciěncia dos Materiais and CENIMAT , FCT/UNL , Quinta da Torre, 2825-114 , Monte de Caparica , Portugal
| | - A. C. Ribeiro
- a Dept. Ciěncia dos Materiais and CENIMAT , FCT/UNL , Quinta da Torre, 2825-114 , Monte de Caparica , Portugal
- b CFMC , Av. Professor Gama Pinto 2, 1649-003 , Lisboa , Portugal
| | - J. L. Figueirinhas
- b CFMC , Av. Professor Gama Pinto 2, 1649-003 , Lisboa , Portugal
- c Dept. Física , IST , Av. Rovisco Pais, 1049-001 , Lisboa , Portugal
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Figueirinhas JL, Cruzi C, Ribeiro AC, Tinh NH. NMR Study of Molecular Order in a Liquid Crystal with Smectic Ad and Reentrant Nematic Mesophases. A Comparative Study with Models for the SAd Phase. ACTA ACUST UNITED AC 2006. [DOI: 10.1080/10587259208037267] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
Affiliation(s)
- J. L. Figueirinhas
- a Centro de Física da Matéria Condensada , Av. Prof. Gama Pinto, 2, 1699 , Lisboa Codex , Portugal
| | - C. Cruzi
- a Centro de Física da Matéria Condensada , Av. Prof. Gama Pinto, 2, 1699 , Lisboa Codex , Portugal
| | - A. C. Ribeiro
- a Centro de Física da Matéria Condensada , Av. Prof. Gama Pinto, 2, 1699 , Lisboa Codex , Portugal
| | - Nguyen Huu Tinh
- b Centre de Recherche , Paul Pascal Domaine Universitaire , 33405 , Talence , France
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Ribeiro AC, Sebastião PJ, Cruz C. Contribution of Proton NMR Relaxation to the Investigation of Molecular Dynamics and Molecular Organisation in Liquid Crystalline Phases. ACTA ACUST UNITED AC 2006. [DOI: 10.1080/10587250108025776] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
Affiliation(s)
- A. C. Ribeiro
- a Institut de Physique et Chimie des Matériaux de Strasbourg - Groupe des Matériaux Organiques - 23 , rue du Loess, 67037 , Strasbourg , Cedex , France
- b CFMC (UL) , Av. Gama Pinto 2, 1649-003 Lisboa, Portugal; IST (UTL), Av. Rovisco Pais, 1049-001 , Lisboa , Portugal
| | - P. J. Sebastião
- b CFMC (UL) , Av. Gama Pinto 2, 1649-003 Lisboa, Portugal; IST (UTL), Av. Rovisco Pais, 1049-001 , Lisboa , Portugal
| | - C. Cruz
- b CFMC (UL) , Av. Gama Pinto 2, 1649-003 Lisboa, Portugal; IST (UTL), Av. Rovisco Pais, 1049-001 , Lisboa , Portugal
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Sebastião PJ, Simeão Carvalho P, Chaves MR, Nguyen HT, Ribeiro AC. Frustrated structure of an anticlinic-like smectic-C phase. Eur Phys J E Soft Matter 2006; 20:55-61. [PMID: 16733639 DOI: 10.1140/epje/i2005-10119-2] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/01/2005] [Accepted: 03/22/2006] [Indexed: 05/09/2023]
Abstract
We present a polarising optical microscopy study of the low-temperature anticlinic-like tilted mesophase of the liquid-crystal compound octylphenyl-2-chloro-4-(p-cyano-benzoyloxy) (DB8Cl). This mesophase has been described as a bilayer smectic structure in which the molecules within each layer are organised in an anticlinic way. The optical textures observed in samples with planar orientation show a double stripe pattern, with the lines aligned parallel to the rubbing direction, characteristic of a double periodic modulation of the refractive index of the material. The long-period modulation is temperature dependent and disappears for thin sample cells (< 5 microm). The short-period modulation is nearly independent of the thickness of the cells. The experimental results are analysed in terms of a model which considers that there is a special distribution of the principal optical axis which may be in or out of the polariser-analyser plane. The observed periodic variation of the principal optical axis could not be interpreted in terms of the original structure proposed for this phase. DB8Cl presents a structure formed by dimers that can be viewed as flexible bent-core-like molecules, showing similarities with phases found in banana-like systems, but exhibiting a much more complex structure.
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Affiliation(s)
- P J Sebastião
- Centro de Física da Matéria Condensada, Av. Prof. Gama Pinto 2, 1649-003, Lisboa Codex, Portugal.
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Sebastião PJ, Sousa D, Ribeiro AC, Vilfan M, Lahajnar G, Seliger J, Zumer S. Field-cycling NMR relaxometry of a liquid crystal above in mesoscopic confinement. Phys Rev E Stat Nonlin Soft Matter Phys 2005; 72:061702. [PMID: 16485959 DOI: 10.1103/physreve.72.061702] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/17/2005] [Indexed: 05/06/2023]
Abstract
We measured the proton spin-lattice relaxation times in the isotropic phase of liquid crystal 4-n-pentyl-4-cyanobiphenyl (5CB) confined into porous glass (CPG) with the average pore diameter approximately 72 nm. The analysis of T1(-1) frequency dispersions, spanning over four decades, shows that the main relaxation mechanism induced by the ordered surface layer are molecular reorientations mediated by translational displacements (RMTD). The RMTD contribution to T1(-1) is proportional to the inverse square root of Larmor frequency, a consequence of the equipartition of diffusion modes along the surface. Low and high frequency cutoffs of the RMTD mechanism clearly reveal that the surface alignment of liquid crystal is random planar with the size of uniformly oriented patches approximately 5 nm, depending on the treatment of the CPG matrix. According to the size of the uniformly oriented patches varies also the thickness of the ordered surface layer and its temperature behavior. The surface-induced order parameter is found to be temperature independent and determined by the local short range surface interactions.
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Affiliation(s)
- P J Sebastião
- Centro de Física da Matéria Condensada, Av. Prof. Gama Pinto 2, 1649-003 Lisbon, Portugal.
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26
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Van-Quynh A, Filip D, Cruz C, Sebastião PJ, Ribeiro AC, Rueff JM, Marcos M, Serrano JL. NMR relaxation study of molecular dynamics in columnar and smectic phases of a PAMAM liquid-crystalline co-dendrimer. Eur Phys J E Soft Matter 2005; 18:149-58. [PMID: 16240071 DOI: 10.1140/epje/i2005-10036-4] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/21/2005] [Accepted: 07/27/2005] [Indexed: 05/04/2023]
Abstract
We present the first results obtained by proton ((1)H) nuclear magnetic relaxation studies of molecular dynamics in a supermolecular liquid-crystal dendrimer exhibiting columnar rectangular and smectic-A phases. The (1)H spin-lattice relaxation time (T(1)) dispersions are interpreted using two relaxation mechanisms associated with collective motions and local molecular reorientations of the dendritic segments in the low- and high-frequency ranges, respectively. The T(1) values show a drop around 2.3 MHz that is attributed to a contribution coming from cross-relaxation between (1)H and nitrogen nuclear spins. In the high-frequency range the motions appear to be of similar nature in both mesophases and are ascribed to reorientations of dendritic segments (belonging to the core and/or to the mesogenic units) characterized by two correlation times. Notable differences in the dynamics between the columnar and layered phases are observed in the low-frequency range. Depending on the mesophase they are discussed in terms of elastic deformations of the columns and layer undulations. In this study we find that the dendritic core influences the dynamics of the mesogenic units both for local and collective motions. These results can be understood in terms of spatial constraints imposed by the dendritic architecture and by the supermolecular arrangement in the mesophases.
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Affiliation(s)
- A Van-Quynh
- Centro de Física da Matéria Condensada, Universidade de Lisboa, Lisboa, Portugal.
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Figueirinhas JL, Cruz C, Filip D, Feio G, Ribeiro AC, Frère Y, Meyer T, Mehl GH. Deuterium NMR investigation of the biaxial nematic phase in an organosiloxane tetrapode. Phys Rev Lett 2005; 94:107802. [PMID: 15783524 DOI: 10.1103/physrevlett.94.107802] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/22/2004] [Indexed: 05/24/2023]
Abstract
Deuterium NMR is used to examine the molecular order exhibited by an organosiloxane tetrapode giving the first experimental evidence, using a bulk sample, for the existence of a biaxial nematic phase in this type of compounds. The temperature dependence of the averaged quadrupolar coupling constant and asymmetry parameter was determined in the compound's nematic phase. Two distinct regimes could be identified, one with a vanishing asymmetry parameter corresponding to a uniaxial nematic phase and another with a significant temperature dependent asymmetry parameter, corresponding to a biaxial nematic phase. The high values obtained for the asymmetry parameter at the lower end of the nematic range are well above experimental error and constitute a definite proof of the biaxial nature of the nematic phase exhibited by the studied compound for those temperatures.
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Affiliation(s)
- J L Figueirinhas
- CFMC-UL, Avenida Professor Gama Pinto 2, 1649-003 Lisboa, Portugal
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28
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Sousa DM, Fernandes PAL, Marques GD, Ribeiro AC, Sebastião PJ. Novel pulsed switched power supply for a fast field cycling NMR spectrometer. Solid State Nucl Magn Reson 2004; 25:160-166. [PMID: 14698404 DOI: 10.1016/j.ssnmr.2003.03.026] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
In this paper, we outline the operating principles of a pulsed switched power supply for a fast field-cycling nuclear magnetic resonance spectrometer. The power supply uses a variant of a four-quadrant chopper with a duty cycle that defines the average output current. With this topology only two semiconductors are necessary to drive hundreds of amperes with an output power of several kilowatts. The output current ripple has a well-defined shape that can be reduced to acceptable values by a careful design of the semiconductors' controlling circuits and drivers. A power supply prototype was tested with a home build air-core magnet operating with fields between 0 and 0.21 T. The system is computer controlled using pulse generator and data acquisition PC cards, and specific user-friendly home-developed software. A comparative proton relaxometry study in two well-known liquid crystal compounds 5CB and MBBA was performed to check the reproducibility of the T1 measurements.
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Affiliation(s)
- D M Sousa
- Instituto Superior Técnico, Av. Rovisco Pais, 1049-001 Lisboa, Portugal
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29
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Ribeiro AC, Heinrich B, Cruz C, Nguyen HT, Diele S, Schröder MW, Guillon D. Rectangular to hexagonal columnar phase transition exhibited by a biforked mesogen. Eur Phys J E Soft Matter 2003; 10:143-151. [PMID: 15011068 DOI: 10.1140/epje/e2003-00018-9] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
We present the structural study of a biforked compound exhibiting a Colr-Colh phase transition. This study was performed by means of DSC, optical microscopy, X-ray diffraction, dilatometry and molecular modelling. The molecular packing within the two columnar mesophases of this compound is discussed. For the first time, it is shown that the clusters of adjacent molecules which form the elementary section of a column are tilted with respect to the columnar axis in the rectangular mesophase. From the whole set of experimental data, the number of molecules in a columnar section is found to be about 5 in the rectangular mesophase, and 4 in the hexagonal one. The transition between the two columnar mesophases is discussed with respect to its slow kinetics.
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Affiliation(s)
- A C Ribeiro
- Institut de Physique et Chimie des Matériaux de Strasbourg, 23 rue du Loess, BP 20, 67037 Strasbourg, France.
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Simpson RHW, Pereira EM, Ribeiro AC, Abdulkadir A, Reis-Filho JS. Polymorphous low-grade adenocarcinoma of the salivary glands with transformation to high-grade carcinoma. Histopathology 2002; 41:250-9. [PMID: 12207787 DOI: 10.1046/j.1365-2559.2002.01439.x] [Citation(s) in RCA: 111] [Impact Index Per Article: 5.0] [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: 11/20/2022]
Abstract
AIMS Polymorphous low-grade adenocarcinoma of the minor salivary glands is an infiltrative neoplasm characterized by bland-looking tumour cells arranged in diverse architectural patterns. It is considered to be of low-grade malignant potential in that nodal metastases are seen in only a minority, and distant spread is rare. Even more unusual is the transformation of polymorphous low-grade adenocarcinoma to a histologically high-grade carcinoma, i.e. dedifferentiation. In this paper, we describe the clinicopathological and immunohistochemical findings in two further examples. METHODS AND RESULTS Two patients presented each with a tumour of the palate. Histopathological examination showed the typical morphological, cytological and immunohistochemical features of a polymorphous low-grade adenocarcinoma. In one case there was a second component of high-grade carcinoma showing nuclear atypia, markedly increased mitotic activity and MIB1 index, as well as prominent zones of necrosis. It expressed epithelial markers and androgen receptors, and thus resembled salivary duct carcinoma. Similar tumour tissue was observed in one of the cervical nodal metastases, which was biopsied at the same time as the palate. In the second patient, a high-grade component was discovered when the tumour recurred in the palate 13 years after the initial biopsy. Whilst morphologically similar to that in first case, there were significant immunohistochemical differences such as retention of some of the polymorphous low-grade adenocarcinoma profile and absence of androgen receptor expression. CONCLUSIONS Polymorphous low-grade adenocarcinoma was first described relatively recently, and as experience with it continues to accumulate, it is becoming clear that late recurrences and metastases, whilst still infrequent, may not be quite as rare as previously thought. Reports of histological transformation are even scarcer, and most occurred at least 13 years after the polymorphous low-grade adenocarcinoma was initially recognized. It is a real possibility that this phenomenon, like clinical progression, may also be encountered more often as time passes. Therefore, we believe that, whilst polymorphous low-grade adenocarcinoma is certainly far less aggressive than, for example, adenoid cystic carcinoma, it nevertheless remains a true malignancy with a potential to prove fatal in a minority of patients.
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Affiliation(s)
- R H W Simpson
- Department of Histopathology, Royal Devon and Exeter Hospital, Exeter, UK.
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31
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Godinho MH, Fonseca JG, Ribeiro AC, Melo LV, Brogueira P. Atomic Force Microscopy Study of Hydroxypropylcellulose Films Prepared from Liquid Crystalline Aqueous Solutions. Macromolecules 2002. [DOI: 10.1021/ma0118769] [Citation(s) in RCA: 39] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- M. H. Godinho
- Dept. Ciência dos Materiais and CENIMAT, Faculdade de Ciências e Tecnologia, Universidade Nova de Lisboa, 2829-516 Caparica, Portugal; Centro de Física da Matéria Condensada, Universidade de Lisboa, 1649-003 Lisboa Portugal; Dept. de Física, Instituto Superior Técnico, 1049-001 Lisboa, Portugal; and ICEMS, Instituto Superior Técnico, 1049-001 Lisboa, Portugal
| | - J. G. Fonseca
- Dept. Ciência dos Materiais and CENIMAT, Faculdade de Ciências e Tecnologia, Universidade Nova de Lisboa, 2829-516 Caparica, Portugal; Centro de Física da Matéria Condensada, Universidade de Lisboa, 1649-003 Lisboa Portugal; Dept. de Física, Instituto Superior Técnico, 1049-001 Lisboa, Portugal; and ICEMS, Instituto Superior Técnico, 1049-001 Lisboa, Portugal
| | - A. C. Ribeiro
- Dept. Ciência dos Materiais and CENIMAT, Faculdade de Ciências e Tecnologia, Universidade Nova de Lisboa, 2829-516 Caparica, Portugal; Centro de Física da Matéria Condensada, Universidade de Lisboa, 1649-003 Lisboa Portugal; Dept. de Física, Instituto Superior Técnico, 1049-001 Lisboa, Portugal; and ICEMS, Instituto Superior Técnico, 1049-001 Lisboa, Portugal
| | - L. V. Melo
- Dept. Ciência dos Materiais and CENIMAT, Faculdade de Ciências e Tecnologia, Universidade Nova de Lisboa, 2829-516 Caparica, Portugal; Centro de Física da Matéria Condensada, Universidade de Lisboa, 1649-003 Lisboa Portugal; Dept. de Física, Instituto Superior Técnico, 1049-001 Lisboa, Portugal; and ICEMS, Instituto Superior Técnico, 1049-001 Lisboa, Portugal
| | - P. Brogueira
- Dept. Ciência dos Materiais and CENIMAT, Faculdade de Ciências e Tecnologia, Universidade Nova de Lisboa, 2829-516 Caparica, Portugal; Centro de Física da Matéria Condensada, Universidade de Lisboa, 1649-003 Lisboa Portugal; Dept. de Física, Instituto Superior Técnico, 1049-001 Lisboa, Portugal; and ICEMS, Instituto Superior Técnico, 1049-001 Lisboa, Portugal
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Ribeiro AC, Joshi VM, Funkhouser WK, Mukherji SK. Inflammatory myofibroblastic tumor involving the pterygopalatine fossa. AJNR Am J Neuroradiol 2001; 22:518-20. [PMID: 11237978 PMCID: PMC7976847] [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] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/19/2023]
Abstract
SUMMARY Inflammatory myofibroblastic tumors (IMT) comprise a rare group of lesions characterized histologically by acute and chronic inflammatory cells with a variable degree of fibrous stroma. Occurrence in the extracranial head and neck in children is unusual, and involvement in the pterygopalatine fossa has not, to our knowledge, been reported as occurring in this age group. We present the CT findings of an IMT of the pterygopalatine fossa in a 6-year-old female patient with a 2-week history of fever and a painless swelling of the left cheek. The diagnosis of IMT should be included in the differential diagnosis of a child presenting with an aggressive mass associated with systemic features such as fever, elevated sedimentation rate, and leukocytosis.
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Affiliation(s)
- A C Ribeiro
- Departments of Radiology, University of North Carolina School of Medicine, Chapel Hill, North Carolina, USA
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Carvalho A, Sebastião PJ, Ribeiro AC, Nguyen HT, Vilfan M. Molecular dynamics in tilted bilayer smectic phases: A proton nuclear magnetic resonance relaxometry study. J Chem Phys 2001. [DOI: 10.1063/1.1413744] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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Brandhagen DJ, Gross JB, Poterucha JJ, Germer JJ, Czaja AJ, Smith CI, Ribeiro AC, Guerrero RB, Therneau TM, Schiff E, Gordon FD, Wiesner RH, Persing DH. Human leukocyte antigen DR markers as predictors of progression to liver transplantation in patients with chronic hepatitis C. Am J Gastroenterol 2000; 95:2056-60. [PMID: 10950057 DOI: 10.1111/j.1572-0241.2000.02137.x] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [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: 12/11/2022]
Abstract
OBJECTIVE Because many patients with chronic viral hepatitis do not progress to end-stage liver disease, it is possible that host factors such as human leukocyte antigen (HLA) differences are important. Our aims were to determine HLA marker-specific rates of progression to liver transplantation among patients with chronic hepatitis C; and to determine if polymerase chain reaction (PCR)-based HLA DRB1 typing can be performed on stored serum samples. METHODS Forty-two hepatitis C virus RNA-positive liver transplant patients and 87 untransplanted patients were included in a Cox proportional hazards model to test whether the occurrence of certain HLA DRB1 markers were associated with progression to liver transplantation. HLA DRB1 typing was performed on stored serum samples using a PCR method. RESULTS There were no differences among the HLA DRB1 markers with regard to the HLA marker-specific rate of progression to transplantation among patients with chronic hepatitis C. CONCLUSIONS HLA DRB1 markers do not appear to be associated with progression of disease in chronic viral hepatitis C. It is possible to perform PCR-based HLA DRB1 typing on stored frozen serum samples.
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Affiliation(s)
- D J Brandhagen
- Department of Health Sciences Research, Mayo Clinic and Foundation, Rochester, Minnesota, USA
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Abstract
BACKGROUND Analgesics (ANA) and nonsteroidal antiinflammatory drugs (NSAID) may simulate an allergic reaction or aggravate asthma and urticaria. OBJECTIVE The aim of this study was the analysis of the clinical findings in patients sensitive to ANA/NSAID. METHODS AND SUBJECTS The charts of 183 patients with history of reacting to these drugs were retrospectively analysed. RESULTS There were 93 (51%) females and 90 (49%) males; 63 (34%) were aged 15 years or less. Females predominate in the age group older than 15 years (p = 0,02). The age by the time of the first reaction varied from 7 months to 65 years (median 15 years). Skin tests to inhalant allergens were positive to at least one antigen in 100/138 patients (72%). Clinical presentation was angioedema (86%); urticaria (39%); systemic reaction (30%); nasal and ocular (15%); and asthma (14%). The frequency of symptoms was not related to age. Family history of ANA/NSAID sensitivity was present in 3.8% of patients. Associated diseases were rhinitis (55%), chronic urticaria (47%), asthma (37%) and conjuntivitis (18%). Among asthmatics 16 (23,5%) had had attacks with ANA/NSAID. Nine non asthmatics (7.7%) had had bronchospasm as clinical presentation. This difference was statistically significant. Repeated reactions occurred in 107 (58%) patients. CONCLUSIONS Sensitivity to ANA/NSAID was frequent in atopics; children and adults responded similarly; reactions were more common in adult females; palpebral angioedema was the most frequent clinical presentation; bronchosphasm was usually seen in asthmatics and most patients reacted repeatedly to different drugs.
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Affiliation(s)
- N A Rosário
- Hospital de Clínicas, Universidade Federal do Paraná, Curitiba, PR
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Ribeiro AC, Gilligan JG, Kapás L. Systemic injection of a nitric oxide synthase inhibitor suppresses sleep responses to sleep deprivation in rats. Am J Physiol Regul Integr Comp Physiol 2000; 278:R1048-56. [PMID: 10749794 DOI: 10.1152/ajpregu.2000.278.4.r1048] [Citation(s) in RCA: 22] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
We hypothesized that nitric oxide (NO) may play a role in homeostatic sleep regulation. To test this hypothesis, we studied the sleep deprivation (SD)-induced homeostatic sleep responses after intraperitoneal administration of an NO synthase inhibitor, Nomega-nitro-L-arginine methyl ester (L-NAME, a cumulative dose of 100 mg/kg). Amounts and intensity of sleep were increased in response to 8 h of SD in control rats (n = 8). Sleep amounts remained above baseline for 16 h after SD followed by a negative rebound. Rapid eye movement sleep (REMS) and non-REMS (NREMS) intensities were elevated for 16 and 4 h, respectively. L-NAME treatment (n = 8) suppressed the rebound increases in NREMS amount and intensity. REMS rebound was attenuated by L-NAME in the first dark period after SD; however, a second rebound appeared in the subsequent dark period. REMS intensity did not increase after SD in L-NAME-injected rats. The finding that the NO synthase inhibitor suppressed rebound increases in NREMS suggests that NO may play a role as a signaling molecule in homeostatic regulation of NREMS.
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Affiliation(s)
- A C Ribeiro
- Department of Biological Sciences, Fordham University, Bronx, New York 10458, USA
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De-Carvalho RR, Maldonado Júnior A, Oliveira Filho EC, Ribeiro AC, Paumgartten FJ, Rey L. Effects of Euphorbia milii latex on Schistosoma mansoni eggs, miracidia and cercariae. Mem Inst Oswaldo Cruz 1999; 93 Suppl 1:235-7. [PMID: 9921358 DOI: 10.1590/s0074-02761998000700042] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Affiliation(s)
- R R De-Carvalho
- Laboratório de Toxicologia Ambiental, Escola Nacional de Saúde Pública, Fiocruz, Rio de Janeiro, Brasil
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Ribeiro AC, Maldonado Júnior A, D'Andrea PS, Vieira GO, Rey L. Susceptibility of Nectomys rattus (Pelzen, 1883) to experimental infection with Schistosoma mansoni (Sambon, 1907): a potential reservoir in Brazil. Mem Inst Oswaldo Cruz 1999; 93 Suppl 1:295-9. [PMID: 9921374 DOI: 10.1590/s0074-02761998000700058] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.5] [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: 11/22/2022] Open
Abstract
The aim of the present research was to evaluate the potential of Nectomys rattus, the "water rat", to develop Schistosoma mansoni infection. Comparison with N. squamipes was carried out. Both species of rodents were submitted to transcutaneous infection using different infective cercariae loads: 50, 100 or 500. N. rattus showed high susceptibility to S. mansoni, with an infection rate of 71%. Rodents were able to excrete viable eggs of S. mansoni in the faeces during all infection period. For both species, the small intestine, followed by the liver and the large intestine, presented the highest concentration of eggs among the surveyed organs. Infection caused no animal death. Moreover, N. rattus accomplished the parasite's life cycle, by infecting the snails Biomphalaria glabrata and later Mus musculus. These evidences indicate that both N. rattus, as for N. squamipes are potential reservoirs for schistosomiasis in Brazil. Considering the fact that N. rattus and N. squamipes exist in the same natural ecosystems of S. mansoni, we suggest that these rodents must be regarded as influential factors in epidemiology surveys.
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Affiliation(s)
- A C Ribeiro
- Departamento de Medicina Tropical, Instituto Oswaldo Cruz, Rio de Janeiro, Brasil.
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Abstract
OBJECTIVE We sought to determine the utility of esophageal manometry in an older patient population. METHODS Consecutively performed manometry studies (470) were reviewed and two groups were chosen for the study, those > or = 75 yr of age (66 patients) and those < or = 50 years (122 patients). Symptoms, manometric findings (lower esophageal sphincter [LES], esophageal body, upper esophageal sphincter [UES]) and diagnoses were compared between the groups. RESULTS Dysphagia was more common (60.6% vs 25.4%), and chest pain was less common (17.9 vs 26.2%) in older patients. In the entire group, there were no differences in LES parameters. Older patients with achalasia had lower LES residual pressures after deglutition (2.7 vs 12.0 mm Hg), but had similar resting pressures (31.4 vs 35.2 mm Hg) compared with younger achalasia patients. Duration and amplitude of peristalsis were similar in both groups, whereas peristaltic sequences were more likely to be simultaneous in the older group (15% vs 4%). The UES had a lower resting pressure in the older patients (49.6 vs 77.6 mm Hg) and a higher residual pressure (2.0 vs -2.7 mm Hg). The older patients were less likely to have normal motility (30.3% vs 44.3%) and were more likely to have achalasia (15.2% vs 4.1%) or diffuse esophageal spasm (16.6% vs 5.0%). When only patients with dysphagia were analyzed, achalasia was still more likely in the older group (20.0% vs 12.9%). CONCLUSION When older patients present with dysphagia, esophageal manometry frequently yields a diagnosis to help explain their symptoms.
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Affiliation(s)
- A C Ribeiro
- Department of Medicine, Mayo Clinic, Jacksonville, Florida 32224, USA
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40
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Affiliation(s)
- A C Ribeiro
- Departamento de Microbiologia, Faculdade de Farmácia de Lisboa, Lisbon, Portugal
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Abstract
Major problems with the treatment of osteomyelitis are associated with poor antibiotic distribution at the site of infection due to limited blood circulation to the skeletal tissue. Improved treatment procedures have been used in drug delivery systems that include bioceramics and natural and synthetic polymers. This work reports the development of anionic collagen:hydroxyapatite composite paste for sustained antibiotic release. Antibiotic release by the composite was characterized by two steps. In the first, 15.0+/-4.9% was released in the first 5 h (n = 53) by a normal Fick diffusion mechanism. In the second step, only 16.8+/-2.2% was released after 7 days. In conclusion, hydroxyapatite:anionic collagen composite can be an efficient support for sustained antibiotic release in the treatment of osteomyelitis because most of the antibiotic release may be associated with composite bioresorption, thus permitting antibiotic release throughout the healing process. Hydroxyapatite:anionic collagen paste showed good biocompatibility associated with bone tissue growth with material still being observed after 60 days from the time of implants.
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Affiliation(s)
- V C Martins
- Depto. Química e Física Molecular, Instituto de Química de São Carlos, Universidade de São Paulo, Brazil
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42
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Ribeiro AC, Cangemi JR. 68-year-old man with peptic ulcer and diarrhea. Mayo Clin Proc 1997; 72:879-82. [PMID: 9294537 DOI: 10.4065/72.9.879] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Affiliation(s)
- A C Ribeiro
- Mayo Graduate School of Medicine, Mayo Clinic Jacksonville, Florida, USA
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Lima M, Porto B, Rodrigues M, Teixeira MA, Coutinho J, Ribeiro AC, Malheiro MI, Justiça B. Cytogenetic findings in a patient presenting simultaneously with chronic lymphocytic leukemia and acute myeloid leukemia. Cancer Genet Cytogenet 1996; 87:38-40. [PMID: 8646738 DOI: 10.1016/0165-4608(95)00262-6] [Citation(s) in RCA: 20] [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] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
A case of simultaneous presentation of B-chronic lymphocytic leukemia (CLL) and acute myeloid leukemia (AML) is described. CLL was documented by bone marrow and peripheral blood lymphocytosis with a typical B-CLL immunophenotype. The diagnosis of AML was supported by the presence of bone marrow and circulating blast cells positive for myeloperoxidase and myeloid-associated markers. Although the immunophenotyping and morphocytochemical studies indicated two different cell populations (mature B-CLL lymphocytes and myeloblasts), chromosome aberrations commonly associated with CLL and AML were found simultaneously in the same metaphases obtained from unstimulated 24-hour cultures of peripheral blood cells.
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MESH Headings
- Aged
- Chromosome Aberrations
- Female
- Humans
- Immunophenotyping
- Leukemia, Lymphocytic, Chronic, B-Cell/genetics
- Leukemia, Lymphocytic, Chronic, B-Cell/immunology
- Leukemia, Myeloid, Acute/genetics
- Leukemia, Myeloid, Acute/immunology
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Affiliation(s)
- M Lima
- Department of Clinical Hematology, S. António's Hospital, Porto, Portugal
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Abbud-Filho M, Barberato JB, Ramalho HJ, Yamazaki WM, Salgueiro MC, Silva ML, Ribeiro AC, Bezas AG. Effects of different immunosuppressive protocols on renal hemodynamics of transplanted patients. Transplant Proc 1994; 26:2594-5. [PMID: 7940805] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Affiliation(s)
- M Abbud-Filho
- Instituto de Urologia e Nefrologia, Sao Jose do Rio Preto, Brazil
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Mulloy B, Ribeiro AC, Alves AP, Vieira RP, Mourão PA. Sulfated fucans from echinoderms have a regular tetrasaccharide repeating unit defined by specific patterns of sulfation at the 0-2 and 0-4 positions. J Biol Chem 1994; 269:22113-23. [PMID: 8071336] [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] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023] Open
Abstract
Sulfated fucans from echinoderms (sea cucumber and sea urchin) have a linear backbone of 1-->3-linked alpha-L-fucopyranose with some sulfate substitution at the 2- and 4-positions. NMR spectroscopy indicates that both polysaccharides have a tetrasaccharide repeat unit in which the separate residues differ only in the extent and position of their sulfate substitution. The sea urchin fucan has the structure, [formula: see text] This type of regular structure has not previously been described, and is in contrast with the random arrangement of substituents on the similar 1-->3-linked alpha-L-fucopyranose backbone of the fucoidans from brown algae.
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Affiliation(s)
- B Mulloy
- National Institute for Biological Standards and Control, Potters Bar, Hertfordshire, United Kingdom
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Carneiro F, Seruca R, Ribeiro AC, Sobrinho-Simões M. An immunohistochemical study of ras oncoprotein expression in gastric carcinoma. Cancer 1994; 73:2010-2. [PMID: 8137234 DOI: 10.1002/1097-0142(19940401)73:7<2010::aid-cncr2820730741>3.0.co;2-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
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Abstract
A purified sulfated alpha-L-fucan from the sea cucumber body wall was studied, before and after almost complete desulfation, using methylation analysis and NMR spectroscopy. NMR analysis indicates that 2,4-di-O-sulfo-L-fucopyranose and unsubstituted fucopyranose are present in equal proportions, and that 2-O-sulfo-L-fucopyranose is present in twice that proportion. There is some NMR evidence that a regular repeating sequence of four residues comprises most or all of the polysaccharide chain.
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Affiliation(s)
- A C Ribeiro
- Departamento de Bioquímica, Universidade Federal do Rio de Janeiro, Brazil
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Mulloy B, Ribeiro AC, Vieira RP, Mourão PA. Structural analysis of sulfated fucans by high-field NMR. Braz J Med Biol Res 1994; 27:515-21. [PMID: 8081275] [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] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023] Open
Abstract
The structures of several sulfated polysaccharides isolated from marine organisms have been determined by a combination of degradative and spectroscopic techniques. For two sulphated fucans, one isolated from the sea cucumber L. grisea, and one from the sea urchin L. variegatus, a novel type of polysaccharide structure is proposed based on the analysis of one- and two-dimensional nuclear magnetic resonance (NMR) spectra. Both polysaccharides are linear, 1-->3 linked alpha-L-fucans in which a four-residue repeating unit is defined by specific patterns of sulfation at the 2- and 4-positions. The four residues give rise to spin systems which may be identified by 2-dimensional 1H-1H correlated spectroscopy (COSY), and the sequence of the residues is deduced from inter-residue nuclear Overhauser enhancements which produce cross-peaks in the NOESY spectrum. To the best of our knowledge, these are the first polysaccharides for which a regular repeating unit is defined by the pattern of sulfate substitution alone.
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Affiliation(s)
- B Mulloy
- Laboratory of Molecular Structure, National Institute for Biological Standards and Control, Hertfordshire, UK
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50
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da Costa Lins RH, Soares DM, van Berg L, Golebiovsky P, Mansur Filho J, Ribeiro AC, Almeida CS, Bomfim V. Surgical treatment of active valvular infective endocarditis. Scand J Thorac Cardiovasc Surg 1988; 22:43-5. [PMID: 3387949 DOI: 10.3109/14017438809106049] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
A review is presented of 20 patients consecutively operated on for acute valvular endocarditis. The diagnosis was established from at least two of the criteria: (a) typical clinical features, (b) two blood cultures positive for the same causal microorganism, and (c) echocardiographic evidence of vegetations. In all cases there was histologic evidence of active infection in the surgical specimen. Only three of the 20 patients had no previous cardiac disease. The most common causal agent was Staphylococcus aureus. The indications for surgery were refractory cardiac failure or infection (18 and 2 cases, respectively). Aortic valve replacement was performed in 16 of the 20 cases, suggesting that aortic valvulopathy aggravates the course of infective endocarditis and increases the risk of heart failure. The overall mortality rate was 30%. All surviving patients were infection-free at postoperative bacteriologic follow-up. Surgery is considered to be the management of choice in active valvular, therapy-resistant bacterial endocarditis with or without cardiac failure.
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Affiliation(s)
- R H da Costa Lins
- Department of Cardiology, Hospital dos Servidores do Estado, Rio de Janeiro, Brazil
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