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1.
Cryo Letters ; 42(4): 210-219, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-35363840

RESUMO

BACKGROUND: Somatic tissue banks represent important tools for the conservation of wild mammals, aiming at the immediate maintenance and safeguarding of biological samples. For agouti, Dasyprocta leporina, studies on the formation of these banks are still scarce, especially regarding protocols of the best cryoprotectant solution employed. OBJECTIVE: To optimize the cryoprotectant solution [ethylene glycol (EG), dimethyl sulfoxide (DMSO), sucrose (SUC)] used for the cryopreservation of agouti somatic tissues. MATERIALS AND METHODS: We treated ear tissues with various cryoprotectant solutions: 3.0 M EG (EG group), 3.0 M EG and 0.25 M SUC (EG-SUC group), 3.0 M DMSO (DMSO group), 3.0 M DMSO and 0.25 M SUC (DMSO-SUC group), 1.5 M EG and 1.5 M DMSO (EG-DMSO group) and 1.5 M EG, 1.5 M DMSO and 0.25 M SUC (EG-DMSO-SUC group). Non-cryopreserved tissues were used as controls. All tissues were analyzed for their ultrastructural and morphometric characteristics by scanning electron microscopy and conventional histology. RESULTS: EG-DMSO-SUC was found to be the optimal cryoprotectant solution in terms of the evaluated parameters, such as thickness of the dermis and skin, number of perinuclear halos, proliferative potential, number of empty lacunas and degenerated chondrocytes. CONCLUSION: Agouti somatic tissue cryopreservation may serve for its conservation and as an experimental model for the development of preservation methods for species of the same genus that are either vulnerable or critically endangered.


Assuntos
Dasyproctidae , Animais , Criopreservação/métodos , Crioprotetores/farmacologia , Dimetil Sulfóxido/farmacologia , Etilenoglicol
2.
Mol Genet Metab ; 124(3): 177-183, 2018 07.
Artigo em Inglês | MEDLINE | ID: mdl-29884465

RESUMO

Newborn screening (NBS) prevents morbidity and mortality by screening babies for selected disorders in the first days of life so that early diagnosis and treatment can be initiated. Congenital disorders impact an estimated 8 million or 6% of annual births worldwide, and of the top five that contribute 25% to the global burden of these disorders, three can be identified and managed by NBS. There are determined pockets of activity in Latin America, Sub-Saharan Africa, and the Asia Pacific region, where partnerships among government, non-governmental organizations, academia, the private sector and civil society are developing novel NBS programs that are both saving lives and preventing disability in those who survive.


Assuntos
Doenças Genéticas Inatas/diagnóstico , Doenças Genéticas Inatas/genética , Triagem Neonatal/história , Triagem Neonatal/métodos , Doenças Genéticas Inatas/epidemiologia , Genética Populacional , Saúde Global , História do Século XX , História do Século XXI , Humanos , Recém-Nascido
3.
Genet Mol Res ; 14(2): 6897-905, 2015 Jun 18.
Artigo em Inglês | MEDLINE | ID: mdl-26125897

RESUMO

The objective of this study was to perform a study of fragile X syndrome (FXS) in São Luís, Maranhão, in males residing in five specialized institutions. Two hundred thirty-eight males with intel-lectual disability of unknown etiology participated in this study. Blood samples were processed and stored until DNA extraction. Screening for FMR1 gene mutations was performed using non-isotopic polymerase chain reaction amplification and DNA sequencing using an ABI Prism 3130 automated sequencer. Two individuals (0.84%) were positive for FMR1 mutations. One had a mutation due to expansion of the CGG repeat beyond normal levels and the other had a deletion in exon 1 of the FMR1 gene, which was confirmed by sequencing. Both probands were over 18 years old, which demonstrates the late diagnosis of the condition in these individuals and reinforces the need to implement ef-fective programs for early diagnosis of FXS in the state of Maranhão. We found that FXS might be transmitted in the families of the two indi-viduals bearing the mutation, and that it is important to understand the mutation dynamics to provide better counseling to the family members of these two individuals.


Assuntos
DNA/genética , Proteína do X Frágil da Deficiência Intelectual/genética , Síndrome do Cromossomo X Frágil/genética , Testes Genéticos , Mutação , Adolescente , Adulto , Brasil , Criança , Pré-Escolar , DNA/isolamento & purificação , Síndrome do Cromossomo X Frágil/diagnóstico , Síndrome do Cromossomo X Frágil/patologia , Aconselhamento Genético , Humanos , Institucionalização , Masculino , Pessoa de Meia-Idade , Linhagem , Reação em Cadeia da Polimerase , Análise de Sequência de DNA
4.
Genet Mol Res ; 14(4): 19094-101, 2015 Dec 29.
Artigo em Inglês | MEDLINE | ID: mdl-26782561

RESUMO

Visceral leishmaniasis (VL) is one of the seven priority endemic diseases in the world. The clinical outcome of many infections is not only dependent on the pathogenic organism, but also on the genetic variability of the host susceptibility to infection. Mannose-binding lectin (MBL) is a protein that plays an important role in the innate immune system. The aim of this study was to compare the serum levels of MBL between healthy controls and carriers of VL. The VL cases were recruited randomly from the main hospitals and referral outpatient clinics for VL in São Luís, and from home visits. Determination of MBL protein levels was performed by enzyme-linked immunosorbent assay. Of the 161 patients with VL and the 161 healthy controls, 60.9 and 67.1% had high levels of MBL, respectively. There was no significant difference in MBL levels between cases and controls. Low socioeconomic status and living conditions are conducive to the occurrence of VL. Owing to the small number of existing studies, it is extremely important to conduct further studies on MBL levels and susceptibility to VL, especially in regions where the disease is endemic, such as Maranhão, Brazil.


Assuntos
Leishmaniose Visceral/sangue , Lectina de Ligação a Manose/sangue , Adolescente , Adulto , Idoso , Brasil , Estudos de Casos e Controles , Criança , Pré-Escolar , Feminino , Humanos , Lactente , Masculino , Pessoa de Meia-Idade , Adulto Jovem
6.
Materials (Basel) ; 17(10)2024 May 14.
Artigo em Inglês | MEDLINE | ID: mdl-38793394

RESUMO

This study investigates the tribocorrosion performance of a cast Co-Cr-Mo alloy prepared using casting and electromagnetic stirring (EMS) at specific frequencies. The tribocorrosion behaviour of the alloy was evaluated when exposed to Ringer's lactate solution to optimize the EMS parameters and improve its properties. The research focuses on biomedical implant applications and explores how EMS affects alloy wear and corrosion resistance. As did the friction coefficient and wear volume, the wear rate of samples produced with EMS frequencies of 75 Hz and 150 Hz decreased. These improvements are attributed to the ability of EMS to refine grain size and homogenize the microstructure, thereby increasing the resistance to tribocorrosion. Techniques such as scanning electron microscopy (SEM) and profilometry were used for surface and wear analysis, while mechanical properties were evaluated through instrumented indentation tests. The findings confirm that EMS improves the alloy's durability and tribocorrosion resistance, making it highly suitable for demanding biomedical applications such as joint replacements. This highlights the importance of advanced manufacturing techniques in optimizing biomedical alloys for simulated body conditions.

7.
Clin Ter ; 174(1): 23-27, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-36655640

RESUMO

Introduction: This study aimed to evaluate the antibiofilm effect of different agents (neutral soap, 4% chlorhexidine, Efferdent effervescent tablets, 1% triclosan, and citronella essential oil) used for ocular prosthesis cleaning. Material and Methods: Biofilms of S. aureus and S. epidermidis were formed on 60 ocular prosthesis acrylic resin specimens. The specimens were cleaned with the studied agents with different techniques. Microorganism counting was performed. Data were submitted to ANOVA and HSD Tukey-Kramer (p<.01). Results: When compared to the control group, all cleaning protocols promoted a reduction in growth of microorganisms. The 4% chlorhexidine, effervescent tablets, and 1% triclosan cleaning agents eliminated biofilm in all groups. Conclusion: Therefore, immersion in 4% chlorhexidine, effervescent tablets, and 1% triclosan could be the best protocols indicated for ocular prosthesis cleaning due to their ability to eliminate biofilm.


Assuntos
Clorexidina , Triclosan , Humanos , Clorexidina/farmacologia , Olho Artificial , Staphylococcus aureus , Triclosan/farmacologia , Biofilmes , Comprimidos/farmacologia
8.
J Fish Biol ; 79(7): 2087-94, 2011 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-22141909

RESUMO

A range expansion of the Taiwan sardinella Sardinella hualiensis to the Philippines is reported. The data suggested that the southern translocation of S. hualiensis occurred across oceanographic features that are typically barriers to small, pelagic fish dispersal. With this addition, the Philippines is among the most diverse countries for Sardinella biodiversity in the world, second only to India.


Assuntos
Peixes/fisiologia , Animais , DNA Mitocondrial/genética , Demografia , Peixes/anatomia & histologia , Peixes/classificação , Peixes/genética , Filipinas , Filogenia , RNA Ribossômico 16S/genética
9.
Mol Microbiol ; 69(2): 361-75, 2008 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-18485068

RESUMO

DNA recombination was investigated by monitoring integration at the rDNA of a circular minichromosome containing a 35S minigene and a replication fork barrier (RFB). The effects of replication fork stalling on integration were studied in wild-type, FOB1Delta, SIR2Delta and the double mutant FOB1DeltaSIR2Delta cells. The results obtained confirmed that Sir2p represses and replication fork stalling enhances integration of the minichromosome. This integration, however, only took place at two distinct sites: the RFB and the 3' end of the 35S gene. For integration to take place at the 35S gene, replication fork stalling must occur at the 3' end of the gene in both the minichromosome and the chromosomal repeats. Integration at the RFB, on the other hand, occurred readily in FOB1Delta cells, indicating that more than a single mechanism triggers homologous recombination at this site. Altogether, these observations strongly suggest that the main role for replication fork stalling at the rDNA locus is to promote homologous recombination rather than just to prevent head-on collision of transcription and replication as originally thought.


Assuntos
Replicação do DNA , DNA Ribossômico/genética , Recombinação Genética , Saccharomyces cerevisiae/fisiologia , Sequência de Bases , Southern Blotting , DNA Ribossômico/metabolismo , Proteínas de Ligação a DNA/genética , Deleção de Genes , Genes Fúngicos , Histona Desacetilases/genética , Dados de Sequência Molecular , Plasmídeos , Proteínas de Saccharomyces cerevisiae/genética , Proteínas Reguladoras de Informação Silenciosa de Saccharomyces cerevisiae/genética , Sirtuína 2 , Sirtuínas/genética
10.
Genet Mol Res ; 7(4): 1097-105, 2008 Oct 21.
Artigo em Inglês | MEDLINE | ID: mdl-19048488

RESUMO

The objective of the present study was to evaluate the genetic variability in micropropagated plantlets of ornamental pineapple, after the fourth period of subculture. The basal culture medium consisted of MS salts, vitamins, 3% sucrose, liquid formulation, supplemented with 6-benzylaminopurine (BAP) at concentrations of 0.125, 0.25, 0.5, 1.0, and 2.0 mg/L. The addition of BAP influenced the occurrence of genetic variation revealed using random amplified polymorphic DNA (RAPD) markers. Of a total of 520 primers tested, 44 were selected and amplified; 402 monomorphic bands (97.2%) and 18 polymorphic bands (2.8%) resulted among regenerated plantlets. The polymorphic fragments were produced by 12 primers (OPA-01, OPA-20, OPB-01, OPB-19, OPC-19, OPF-13, OPL-17, OPM-13, OPP-16, OPT-07, OPV-19, and OPX-03). Among the primers that identified polymorphism, OPA-01, OPA-20, OPB-19, OPC-19, OPL-17, OPP-16, and OPX-3 each showed, one polymorphic band and OPF-13 amplified a maximum of three bands. In this study, the RAPD technique was effective in showing the occurrence of somaclonal variations that occur during the micropropagation process of ornamental pineapple cultivation in BAP-supplemented medium, and it is possible to detect the presence of genetic variation in early stages of plant development.


Assuntos
Ananas/genética , Variação Genética , Técnica de Amplificação ao Acaso de DNA Polimórfico/métodos , Primers do DNA/genética , DNA de Plantas/genética , DNA de Plantas/metabolismo , Marcadores Genéticos/genética
11.
Braz J Biol ; 66(3): 931-8, 2006 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-17119841

RESUMO

One hundred and thirteen specimens of Franciscodoras marmoratus (Reinhardt, 1874) were collected in the upper São Francisco River (18 degrees 12' 32" S, 45 degrees 15' 41" W, state of Minas Gerais) between September, 1999 and January, 2004 to investigate their parasite fauna. From this total, 45 (39.8%) were afflicted by at least one parasite species. The parasitic richness consisted of six species represented by Hirudinea (n = 20), Monogenoidea (n = 25), Eucestoda (n = 55), Nematoda (n = 1, n = 2) and Acanthocephala (n = 41) found in the dry and wet periods making a total of 144 specimens. Proteocephalus renaudi Chambrier & Vaucher, 1994 was the only species with prevalence higher than 10% and a typical aggregate distribution pattern. The prevalence, intensity and abundance of P. renaudi were not influenced by the total length or sex of the hosts or by the collection periods. The relative condition factor indicated that the health of the P. renaudi hosts was not significantly affected in relation to fish not infected by parasites. The fish stocked in tanks before necropsy were opportunistically infested by Lernaea cyprinacea Yashuv, 1959. The various parasites found indicate that F. marmoratus is omnivorous and a potential definitive host. The parasite species, except for Acanthocephala, have expanded their known geographic distribution to the São Francisco River Basin. The parasite community was considered isolationist because of the low endoparasite diversity, infrapopulations with low intensity, lack of evidence of parasite interactions and sparse signs of parasite aggression against their hosts.


Assuntos
Peixes-Gato/parasitologia , Parasitos/isolamento & purificação , Animais , Brasil , Feminino , Interações Hospedeiro-Parasita , Masculino , Parasitos/classificação , Parasitos/fisiologia , Rios , Estações do Ano
12.
Braz J Med Biol Res ; 38(9): 1331-8, 2005 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-16138216

RESUMO

The effects of the aging process and an active life-style on the autonomic control of heart rate (HR) were investigated in nine young sedentary (YS, 23 +/- 2.4 years), 16 young active (YA, 22 +/- 2.1 years), 8 older sedentary (OS, 63 +/- 2.4 years) and 8 older active (OA, 61 +/- 1.1 years) healthy men. Electrocardiogram was continuously recorded for 15 min at rest and for 4 min in the deep breathing test, with a breath rate of 5 to 6 cycles/min in the supine position. Resting HR and RR intervals were analyzed by time (RMSSD index) and frequency domain methods. The power spectral components are reported in normalized units (nu) at low (LF) and high (HF) frequency, and as the LF/HF ratio. The deep breathing test was analyzed by the respiratory sinus arrhythmia indices: expiration/inspiration ratio (E/I) and inspiration-expiration difference (deltaIE). The active groups had lower HR and higher RMSSD index than the sedentary groups (life-style condition: sedentary vs active, P < 0.05). The older groups showed lower HFnu, higher LFnu and higher LF/HF ratio than the young groups (aging effect: young vs older, P < 0.05). The OS group had a lower E/I ratio (1.16) and deltaIE (9.7 bpm) than the other groups studied (YS: 1.38, 22.4 bpm; YA: 1.40, 21.3 bpm; OA: 1.38, 18.5 bpm). The interaction between aging and life-style effects had a P < 0.05. These results suggest that aging reduces HR variability. However, regular physical activity positively affects vagal activity on the heart and consequently attenuates the effects of aging in the autonomic control of HR.


Assuntos
Envelhecimento/fisiologia , Sistema Nervoso Autônomo/fisiologia , Exercício Físico/fisiologia , Frequência Cardíaca/fisiologia , Coração/inervação , Adulto , Fatores Etários , Idoso , Eletrocardiografia , Teste de Esforço , Humanos , Masculino , Pessoa de Meia-Idade , Respiração
13.
J Comp Pathol ; 153(4): 206-11, 2015 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-26604083

RESUMO

Sheep-associated malignant catarrhal fever (SA-MCF) is an important infectious disease of ruminants worldwide that is caused by ovine herpesvirus 2 (OvHV-2). OvHV-2 is transmitted predominantly by contact between infected and susceptible hosts, while the documentation of vertical transmission is rare. This report presents the pathological and molecular findings associated with transplacental transmission of OvHV-2 in cattle. Two Girolanda cows with corneal oedema, lethargy, mucopurulent nasal discharge and ulcerative stomatitis died spontaneously; one of these was pregnant with a 4-month-old fetus. Significant pathological findings included widespread lymphoplasmacytic necrotizing vasculitis and lymphoplasmacytic accumulations in several organs of both cows and the fetus. A polymerase chain reaction that targeted the tegument protein gene of OvHV-2 amplified viral DNA from the brain of the pregnant cow and her fetus, as well as from the kidney of the pregnant cow. The pathological findings observed in the cow and her fetus, together with the presence of OvHV-2 DNA in tissues of these animals, are suggestive of transplacental transmission of OvHV-2 in SA-MCF in cattle.


Assuntos
Transmissão Vertical de Doenças Infecciosas , Febre Catarral Maligna/transmissão , Doenças dos Ovinos , Animais , Bovinos , Feminino , Herpesviridae , Reação em Cadeia da Polimerase , Gravidez , Ovinos
14.
Arq. bras. med. vet. zootec. (Online) ; 72(3): 673-680, May-June, 2020. ilus, tab
Artigo em Português | LILACS, VETINDEX | ID: biblio-1128724

RESUMO

A cotonicultura tem forte fator de impacto na economia nacional, e o estado de Mato Grosso se destaca por ser o maior produtor de algodão herbáceo e deter o maior rebanho bovino do país, condições essas que estimulam o uso do caroço, da torta e do farelo de algodão na alimentação animal. Considerando que o gossipol está presente nos subprodutos do algodão e que seus efeitos sobre a reprodução podem reduzir a fertilidade dos animais, objetivou-se, com essa pesquisa, avaliar o efeito da ingestão de dietas com diferentes teores de gossipol livre por dia sobre a morfometria testicular e a qualidade seminal de touros da raça Nelore. Foram utilizados 28 touros, distribuídos aleatoriamente em seis tratamentos: T0, 0 grama de gossipol livre/touro/dia ; T1, 1,08 grama de gossipol livre/touro/dia; T2, 2,07 gramas de gossipol livre/touro/dia; T3, 3,24 gramas de gossipol livre/touro/dia; T4, 3,82 gramas de gossipol livre/touro/dia e T5, 5,08 gramas de gossipol livre/touro/dia. Os animais de cada tratamento foram mantidos confinados em área média de 100m2, dotada de bebedouro, cochos para mistura mineral e para volumoso/concentrado. O consumo de 3,24 gramas de gossipol livre/touro/dia alterou a qualidade espermática e a morfometria testicular de touros.(AU)


The cotton industry has a strong impact factor in the Brazilian economy and the state of Mato Grosso stands out for being the largest upland-type cotton producer and also holds the largest cattle herd in the country, conditions that stimulate the use of cottonseed pie and cottonseed meal in animal feed. Whereas gossypol is present in cotton by-products and their effects on reproduction can reduce the animal fertility, this research evaluated the effect of diets with different free gossypol contents in the testicular morphometry and semen quality of Nelore bulls. 28 bulls were randomly distributed in six treatments: T0, receiving no free gossypol; T1, receiving 1.08g / bull / day; T2, receiving 2.07g / bull / day; T3, receiving 3.24g / bull / day; T4, receiving 3.82g / bull / day and T5, receiving 5.08g / bull / day of free gossypol respectively. The animals in each treatment were kept confined in an averaged area of 100m2, having fresh water, troughs for mineral mixture and roughage / concentrate. The consumption of 3.24g of free gossypol / bull / day altered the bulls sperm quality and testicular morphometry.(AU)


Assuntos
Animais , Masculino , Bovinos , Testículo/anatomia & histologia , Óleo de Sementes de Algodão/administração & dosagem , Gossipol/administração & dosagem , Análise do Sêmen , Infertilidade Masculina/veterinária
15.
Neurotoxicology ; 20(6): 871-82, 1999 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-10693968

RESUMO

In the present study, the whole-cell mode of the patch-clamp technique was applied to neurons of the CA1 pyramidal layer of rat hippocampal slices to investigate the effects of the organophosphate (OP) sarin on field stimulation-evoked and on tetrodotoxin (TTX)-insensitive postsynaptic currents (PSCs) mediated by activation of type A gamma-aminobutyric acid (GABA) receptors or AMPA-type glutamate receptors. At 0.3-1 nM, sarin reduced the amplitude of GABA-mediated PSCs and had no effect on the amplitude of glutamatergic PSCs evoked by field stimulation of neurons synaptically connected to the neuron under study. The effect of sarin on evoked GABAergic PSCs was unrelated to cholinesterase inhibition, was partially reversed upon washing of the neurons with sarin-free external solution, and was mediated by a direct interaction of the OP with muscarinic acetylcholine receptors present on presynaptic GABAergic neurons. Sarin had no effect on the amplitude or kinetics of GABA- or glutamate-mediated miniature postsynaptic currents (MPSCs) recorded in the presence of the Na+-channel blocker TTX (300 nM), indicating that the OP does not interact with GABA(A) or glutamate receptors. Further, sarin did not alter the frequency of GABAergic or glutamatergic MPSCs, a finding that led to the conclusion that this OP does not affect the TTX-insensitive release of neurotransmitters. A selective reduction by sarin of the action potential-dependent release of GABA in the hippocampus can account for the occurrence of seizures in intoxicated subjects.


Assuntos
Potenciais Evocados/efeitos dos fármacos , Hipocampo/efeitos dos fármacos , Compostos Organofosforados/toxicidade , Receptores de GABA/efeitos dos fármacos , Sarina/toxicidade , Ácido gama-Aminobutírico/metabolismo , Animais , Relação Dose-Resposta a Droga , Estimulação Elétrica , Técnicas In Vitro , Técnicas de Patch-Clamp , Ratos , Ratos Sprague-Dawley , Receptores de Glutamato/efeitos dos fármacos , Sinapses/efeitos dos fármacos , Tetrodotoxina/toxicidade
16.
Neurotoxicology ; 18(2): 589-602, 1997.
Artigo em Inglês | MEDLINE | ID: mdl-9291508

RESUMO

Methamidophos (O,S-dimethyl phosphoroamidothiolate, Tamaron), an organophosphate (OP) anticholinesterase of limited toxicity, is widely used as an insecticide and acaricide. To provide additional insight into the molecular basis of its action, we have used electrophysiological and biochemical techniques to study the effects of methamidophos on the neuromuscular junction of rat and frog and on the central nervous system of rat. Methamidophos has a relatively weak inhibitory action on cholinesterases in rat diaphragm muscle, brain and hippocampal homogenates, with IC50 values on the order of 20-20 microM. An even weaker anticholinesterase activity was found in frog muscle homogenates, with the IC50 being above 300 microM. As further evidence of anticholinesterase activity, methamidophos (1-100 microM) was able to reverse the blockade by d-tubocurarine (0.5-0.7 microM) of neuromuscular transmission in rat phrenic nerve-hemidiaphragm preparations. Inhibition of cholinesterase activity by methamidophos was long lasting, which is consistent with the formation by the agent of a covalent bond with the enzyme's active serine residue. The action was also slowly reversible, which suggests spontaneous reactivation of the enzyme. electrophysiological studies at the rat neuromuscular junction showed that, due to its anticholinesterase activity, methamidophos increased the amplitude and prolonged the decay phase of nerve-evoked and spontaneous miniature end-plate potentials. In contrast to other OP compounds, e.g., paraoxon (Rocha et al., 1996a), methamidophos did not affect neurotransmitter release, nor did it interact directly with the muscle nicotinic acetylcholine receptor. Moreover, it contrast to paraoxon, methamidophos did not affect the whole-cell currents induced by application of acetylcholine, glutamate or gamma-aminobutyric acid recorded to cultured hippocampal neurons. Based on these data, methamidophos appears to have a selective effect on cholinesterase.


Assuntos
Inibidores da Colinesterase/toxicidade , Inseticidas/toxicidade , Neurotransmissores/metabolismo , Compostos Organotiofosforados/toxicidade , Sinapses/efeitos dos fármacos , Animais , Diafragma/efeitos dos fármacos , Diafragma/inervação , Potenciais Evocados/efeitos dos fármacos , Técnicas In Vitro , Canais Iônicos/efeitos dos fármacos , Masculino , Placa Motora/efeitos dos fármacos , Contração Muscular/efeitos dos fármacos , Técnicas de Patch-Clamp , Ratos , Ratos Wistar , Sinapses/metabolismo
17.
Chem Biol Interact ; 116(1-2): 105-22, 1998 Nov 06.
Artigo em Inglês | MEDLINE | ID: mdl-9877204

RESUMO

The following aspects were investigated in the present work: (a) the action of flufenamic acid on hepatic metabolism (oxygen uptake, glycolysis, gluconeogenesis, uricogenesis and glycogenolysis), (b) the action of flufenamic acid on the cellular adenine nucleotide levels, and (c) the transport and distribution space of flufenamic acid in the liver parenchyma. The experimental system was the isolated perfused rat liver. Perfusion was accomplished in an open, non-recirculating system. The perfusion fluid was Krebs/Henseleit-bicarbonate buffer (pH 7.4), saturated with a mixture of oxygen and carbon dioxide (95:5) by means of a membrane oxygenator and heated to 37 degrees C. The distribution space of flufenamic acid was measured by means of the multiple-indicator dilution technique with constant infusion (step input) of [3H]water plus flufenamic acid. The results of the present work indicate that the metabolic effects of flufenamic acid are the consequence of an uncoupling of oxidative phosphorylation, a conclusion based on the following observations: (a) flufenamic acid increased oxygen uptake, a common property of all uncouplers; (b) the drug also increased glycolysis and glycogenolysis in livers from fed rats (these are expected compensatory phenomena for the decreased mitochondrial ATP formation); (c) flufenamic acid inhibited glucose production from fructose, an energy-dependent process; (d) the cellular ATP levels were decreased by flufenamic acid whereas the AMP levels were increased; and (e) the total adenine nucleotide content was decreased by flufenamic acid and uric acid production was stimulated. Indicator-dilution experiments with flufenamic acid revealed that this substance undergoes flow-limited distribution in the liver and that its apparent distribution space greatly exceeds the aqueous space of the liver. Flufenamic acid changed its behaviour when the portal concentration was increased from 25 to 50 microM. At 25 microM the initial upslope of the outflow profile clearly preceded that of all other concentrations. From the trend of the curves obtained with 50, 100 and 250 microM, one would expect an initial upslope situated at the right of the 50-microM curve. Furthermore, the time of appearance of flufenamic acid in the outflowing perfusate was practically the same irrespective of the portal concentration. For theoretical reasons one would expect progressively longer appearance times when the portal concentration was decreased. It is possible that the amount of flufenamic acid bound to the cell membranes during the early stages of the infusion produced changes that enabled these structures to bind a larger quantity of the drug than originally possible.


Assuntos
Anti-Inflamatórios não Esteroides/farmacologia , Ácido Flufenâmico/farmacologia , Fígado/efeitos dos fármacos , Fígado/metabolismo , Nucleotídeos de Adenina/metabolismo , Trifosfato de Adenosina/metabolismo , Animais , Frutose/metabolismo , Glicogênio Hepático/metabolismo , Masculino , Oxigênio/metabolismo , Perfusão , Ratos , Ratos Wistar , Distribuição Tecidual , Ácido Úrico/metabolismo
18.
J Endod ; 25(9): 609-12, 1999 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-10687539

RESUMO

This study evaluated the sectional gutta-percha obturation technique advocated by Lightspeed Technology, Inc. Single relatively straight-canaled teeth were prepared with rotary instruments and divided into three groups. Groups A and B served as controls and were obturated using laterally condensed gutta-percha and either Roth's 801 or Ketac-Endo sealer. Group C was obturated using the Lightspeed technique that included placement of a 5-mm apical section of gutta-percha, followed by backfill with Ketac-Endo sealer and a single gutta-percha cone. All teeth were suspended in India ink for 14 days then cleared. Four additional teeth, which were obturated as in group C then sectioned, revealed a tightly adapted apical section of gutta-percha with a very thin layer of sealer. However, voids were noted in the middle and coronal areas. There was no significant difference in apical microleakage among the three groups. The sectional method was significantly faster than lateral condensation and seems to offer promise as an effective obturation method.


Assuntos
Infiltração Dentária , Obturação do Canal Radicular/métodos , Distribuição de Qui-Quadrado , Equipamentos Odontológicos de Alta Rotação , Estudos de Avaliação como Assunto , Cimentos de Ionômeros de Vidro , Guta-Percha , Humanos , Materiais Restauradores do Canal Radicular , Estatísticas não Paramétricas , Ápice Dentário , Cimento de Óxido de Zinco e Eugenol
19.
Poult Sci ; 76(10): 1342-8, 1997 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-9316108

RESUMO

A series of experiments were carried out in order to determine doxycycline hydrochloride (DoxHCl) plasma levels in 6-wk-old turkeys medicated via drinking water containing DoxHCl at a concentration of 250 mg/L under laboratory and field conditions. Maximal plasma concentration (Cmax) values of 5.7 (+/-1.0) microgram/mL and 4.9 (+/-1.4) micrograms/mL obtained after DoxHCl administration during 2 and 7 d, respectively, were not significantly different. A significant difference was found between the area under the plasma concentration-time profile, calculated between 0 and 168 h (AUC(0-168)), Cmax, and the minimal plasma concentration (Cmin) values obtained after medication with a DoxHCl solution at a concentration of 250 mg/L (431.9 +/- 96.6 micrograms.h/mL, 4.9 +/- 1.4 micrograms/mL and 0.7 +/- 0.3 microgram/mL) and after medication with a DoxHCl solution at a concentration of 750 mg/L (1,176.5 +/- 201.8 micrograms.h/mL, 12.5 +/- 2.7 micrograms/mL and 2.9 +/- 0.4 micrograms/mL), respectively. The increase in body weight was also significantly higher for turkeys medicated with a DoxHCl solution at a concentration of 750 mg/L (83.7 g/d) than for the lower concentration (35.6 g/d). The DoxHCl solution uptake significantly decreased with the increase of DoxHCl concentration. A Cmax value of 1.7 +/- 0.6 micrograms/mL and a Cmin value of 0.5 +/- 0.1 microgram/mL were observed during the field experiment. Water consumption under laboratory conditions was followed for tap water (70 +/- 50 mL/kg.d) and for a DoxHCl solution at a concentration of 250 mg/L supplemented with 1 g anhydrous citric acid/L (119 +/- 6 mL/kg.d) and revealed to be not significantly different. The variability was significantly higher for tap water than for the DoxHCl solution. The stability of the DoxHCl solution containing 1 g citric acid/L over 24 h was 99% expressed as the percentage of the initial concentration.


Assuntos
Doxiciclina/administração & dosagem , Ingestão de Líquidos/fisiologia , Tetraciclinas/administração & dosagem , Perus/sangue , Administração Oral , Animais , Disponibilidade Biológica , Peso Corporal/fisiologia , Ácido Cítrico/farmacologia , Simulação por Computador , Relação Dose-Resposta a Droga , Doxiciclina/sangue , Doxiciclina/farmacocinética , Temperatura , Tetraciclinas/sangue , Tetraciclinas/farmacocinética , Fatores de Tempo , Perus/fisiologia
20.
Appl Radiat Isot ; 61(6): 1343-7, 2004 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-15388131

RESUMO

In this work we have studied the direct detection and spectrometric capabilities of low-cost commercial silicon photodiodes for X- and gamma-rays (energies from 10 up to 80 keV) envisaging their use in characterization of porous microstructures by X-ray microtomography. The best values of the energy resolution for the 59.5 keV 241Am gamma-ray line, measured at room temperature, were found to be 2.1 and 1.8 keV for SFH00206K (Siemens) and S2506-04 (Hamamatsu) PIN diodes, respectively.


Assuntos
Fótons , Radiometria/instrumentação , Semicondutores , Raios gama , Doses de Radiação , Radiometria/métodos , Reprodutibilidade dos Testes , Sensibilidade e Especificidade , Temperatura , Raios X
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