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2.
Arq. bras. med. vet. zootec. (Online) ; 72(1): 145-152, Jan.-Feb. 2020. tab
Article in English | LILACS, VETINDEX | ID: biblio-1088907

ABSTRACT

This study aimed to evaluate the addition of Vitamin C, reduced Glutathione and trolox on sperm characteristics of pork refrigerated semen. Six pigs were collected through the technique of gloved hand (10 ejaculates/animals). The semen was diluted in MR-A®. After the previous evaluations, the treatments were added: Control group: diluent only; Vitamin C Group: 200µM/mL Vitamin C; Trolox Group: 200µM/mL Trolox; Glutathione group: 2.5mM/ml Reduced glutathione. The semen was stored in thermal boxes and placed inside the refrigerator at 15oC and evaluated at D0, 12, 48, 72 hours. After 30 hours of incubation, each treatment was divided into two equal fractions and the same concentration of antioxidants was added in one of the parts. The results show that reduced glutathione supplementation preserves sperm motility after 24 hours but also has a higher percentage of acrosome intact in the presence of this antioxidant. There was no effect of adding a second dose of the antioxidants. In conclusion, the addition of reduced Glutathione to the swine semen diluent is a promising alternative for better preservation of sperm characteristics and the addition of the second dose of antioxidants during storage is detrimental to semen.(AU)


Este estudo tem como objetivo avaliar a adição da vitamina C, da glutationa reduzida e do trolox sobre características espermáticas do sêmen refrigerado de suínos. Seis cachaços foram coletados pela técnica de mão enluvada (10 coletas/animal). O sêmen foi diluído em MR-A®. Após as avaliações prévias, os tratamentos foram adicionados: grupo controle: apenas diluidor; grupo vitamina C: 200µM/mL de vitamina C; grupo trolox: 200µM/mL de trolox; grupo glutationa: 2.5mM/mL de glutationa reduzida. O sêmen foi armazenado em caixas térmicas e alocado dentro do refrigerador a 15oC e avaliado nos tempos zero, 12, 48 e 72 horas . Após 30 horas de incubação, cada tratamento foi dividido em duas frações iguais e adicionou-se a mesma concentração de antioxidantes em uma das partes. Os resultados demonstram que a suplementação de glutationa reduzida preserva a motilidade espermática após 24 horas, bem como tem maior percentual de acrossoma intacto na presença desse antioxidante. Não houve efeito ao se adicionar uma segunda dose dos antioxidantes. Em conclusão, o acréscimo da glutationa reduzida ao diluidor de sêmen suíno é uma alternativa promissora para melhor preservação das características espermáticas, e a adição da segunda dose dos antioxidantes durante o armazenamento é prejudicial ao sêmen.(AU)


Subject(s)
Animals , Male , Ascorbic Acid/administration & dosage , Semen Preservation/methods , Spermatozoa , Swine , Glutathione/administration & dosage , Semen Preservation/veterinary , Antioxidants/analysis
3.
Arq. bras. med. vet. zootec. (Online) ; 71(3): 811-818, May-June 2019. tab, ilus
Article in English | VETINDEX, LILACS | ID: biblio-1011292

ABSTRACT

Trauma or disease inflicted by tissue injuries may cause tissue degeneration. The use of biomaterials for direct or indirect repair has emerged as a promising alternative, and has become an important research topic. The pequi fruit (Caryocar brasiliense Camb.) has shown antifungal, antibacterial, anti-inflammatory, healing, antitumor, and antioxidant properties. The objective of this study was to develop a new biomaterial using a combination of collagen, gelatin, and pulp pequi oil, and to evaluate its biocompatibility in comparison with that of biomaterials produced without pulp pequi oil. Membranes were prepared from a mixture of bovine tendon collagen, commercial gelatin, and pulp pequi oil. The inflammatory and cicatricial processes were assessed via histopathology of the tissue interface/implants in the subcutaneous tissues and quantitative evaluation of leukocyte and collagen production in Wistar rats. It was observed that the presence of pequi oil reduced the amount of foreign-body giant cells and favored the recruitment of fibroblasts (P< 0.01), thereby promoting greater production of collagen membrane than that in the membranes of control samples. Therefore, it can be concluded that the addition of pequi oil improved the biocompatibility of collagen and accelerated the healing process.(AU)


Trauma ou lesões causadas por doenças podem enfraquecer e degenerar os tecidos humanos e animais. O uso de biomateriais para reparação direta ou indireta surgiu como uma alternativa promissora e tornou-se um importante tema de pesquisa. O óleo de pequi (Caryocar brasiliense Camb.) mostrou propriedades antifúngicas, antibacterianas, anti-inflamatórias, curativas, antitumorais e antioxidantes. O objetivo deste estudo foi obter um novo biomaterial, produzido pela combinação de óleo de pequi, colágeno e gelatina, para avaliar sua biocompatibilidade em comparação às membranas produzidas sem o óleo. As membranas foram preparadas por meio da mistura de colágeno de tendão bovino, gelatina comercial e óleo de pequi. Os processos inflamatórios e cicatriciais foram avaliados por histopatologia da interface / implantes de tecido subcutâneo de ratos Wistar para avaliação quantitativa da produção de leucócitos e colágeno. Observou-se que a presença de óleo de pequi reduziu a quantidade de células gigantes de corpo estranho e favoreceu o recrutamento de fibroblastos (P<0,01), promovendo, assim, maior produção da membrana de colágeno em comparação com a membrana de controle. Portanto, pode-se concluir que a adição de óleo de pequi melhorou a biocompatibilidade do colágeno e acelerou o processo de cicatrização.(AU)


Subject(s)
Animals , Rats , Biocompatible Materials/therapeutic use , Soft Tissue Injuries/veterinary , Ericales , Wound Healing , Collagen/therapeutic use , Gelatin/therapeutic use
4.
Arq. bras. med. vet. zootec ; 68(6): 1531-1538, nov.-dez. 2016. tab, ilus
Article in English | LILACS, VETINDEX | ID: biblio-827927

ABSTRACT

As lesões em membros de grandes animais são um desafio para médicos veterinários, uma vez que somente a osteossíntese não garante resultados satisfatórios. Muitos pesquisadores vêm se dedicando ao desenvolvimento e estudo de substitutos ósseos produzidos de materiais naturais, como quitosana, colágeno e hidroxiapatita, que auxiliam na regeneração óssea. Seis ovinos fêmeas da raça Santa Inês foram submetidos a ostectomias unicorticais de sete milímetros de diâmetro na região proximal da superfície dorsomedial dos III/IV metacarpianos. Foi implantado compósito de quitosana, colágeno e hidroxiapatita em um membro torácico para avaliação da biocompatibilidade do material ao tecido ósseo ovino, e no membro contralateral foi reproduzida a mesma técnica, porém foi mantido sem preenchimento, como controle. Após 60 dias do procedimento cirúrgico, realizou-se biópsia óssea na área de interface entre biomaterial/osso (membro com compósito) e tecido neoformado/osso (membro controle), para realização de avaliação histológica do material não descalcificado, por meio de microscopia de luz e microscopia eletrônica de varredura. Na análise histomorfométrica, mediante microscopia de luz, foi possível identificar maior porcentagem de tecido neoformado em membro controle, quando comparado ao membro com compósito (80% e 63,5%, respectivamente; P<0,05). Por meio da microscopia eletrônica de varredura, observou-se invasão da estrutura interna do compósito por tecido ósseo neoformado. Não houve formação de tecido cicatricial, reação de corpo estranho ou resposta inflamatória crônica nas amostras analisadas. Conclui-se que o compósito de quitosana, colágeno e hidroxiapatita, quando implantado em tecido ósseo ovino, apresenta biocompatibilidade e perfil osteocondutor.(AU)


Fracture management poses a great challenge to large animal practitioners. Osteosynthesis alone is often insufficient to provide satisfactory outcomes in large animals; therefore, several research efforts have been made to investigate and develop bone substitutes capable of promoting bone regeneration. Chitosan-collagen-hydroxyapatite composites constitute a promising alternative given their similar composition to bone. Six Santa Inês ewes were submitted to the creation of experimental 7mm wide unicortical defects on the dorsomedial aspect of the proximal III/IV metacarpal bone diaphysis. Limbs were randomly selected for treatment with chitosan-collagen-hydroxyapatite composite or to serve as untreated controls. Biopsy fragments were collected from the bone/new bone or the bone/biomaterial interface (control and treated defects respectively) within 60 days of surgery; composite biocompatibility was assessed using light and scanning electron microscopy. Histomorphometric analysis under light microscopy revealed greater percentage of new bone tissue in control compared to treated defects (80% and 63.5% respectively; P<0.05). No scar tissue formation, foreign body or chronic inflammatory reactions were observed. Scanning electron microscopy revealed invasion of the composite by new bone tissue. The chitosan-collagen-hydroxyapatite composite studied is biocompatible with bone and shows osteoconductive properties in sheep.


Subject(s)
Animals , Biocompatible Materials/analysis , Bone and Bones , Bone Substitutes/analysis , Sheep , Bone Regeneration , Chitosan/therapeutic use , Collagen/therapeutic use , Hydroxyapatites , Microscopy, Electron, Scanning/veterinary
5.
Braz. j. med. biol. res ; 48(9): 852-862, Sept. 2015. tab, ilus
Article in English | LILACS | ID: lil-756406

ABSTRACT

The antioxidant effects of Caryocar brasiliense Camb, commonly known as the pequi fruit, have not been evaluated to determine their protective effects against oxidative damage in lung carcinogenesis. In the present study, we evaluated the role of pequi fruit against urethane-induced DNA damage and oxidative stress in forty 8-12 week old male BALB/C mice. An in vivo comet assay was performed to assess DNA damage in lung tissues and changes in lipid peroxidation and redox cycle antioxidants were monitored for oxidative stress. Prior supplementation with pequi oil or its extract (15 µL, 60 days) significantly reduced urethane-induced oxidative stress. A protective effect against DNA damage was associated with the modulation of lipid peroxidation and low protein and gene expression of nitric oxide synthase. These findings suggest that the intake of pequi fruit might protect against in vivo genotoxicity and oxidative stress.


Subject(s)
Animals , Male , Mice , Antioxidants/pharmacology , DNA Damage/drug effects , Ericales/chemistry , Lung Neoplasms/prevention & control , Oxidative Stress/drug effects , Plant Extracts/pharmacology , Carcinogenesis , Carcinogens , Comet Assay , Genome , Immunohistochemistry , Lipid Peroxidation/drug effects , Lung Neoplasms/chemically induced , Lung Neoplasms/pathology , Mice, Inbred BALB C , Urethane
6.
Braz. j. med. biol. res ; 48(6): 557-567, 06/2015. tab, graf
Article in English | LILACS | ID: lil-748226

ABSTRACT

Hyaluronan (HA) shows promise for detecting cancerous change in pleural effusion and urine. However, there is uncertainty about the localization of HA in tumor tissue and its relationship with different histological types and other components of the extracellular matrix, such as angiogenesis. We evaluated the association between HA and degree of malignancy through expression in lung tumor tissue and sputum. Tumoral tissue had significantly increased HA compared to normal tissue. Strong HA staining intensity associated with cancer cells was significant in squamous cell carcinoma compared to adenocarcinoma and large cell carcinoma. A significant direct association was found between tumors with a high percentage of HA and MVD (microvessel density) in tumoral stroma. Similarly significant was the direct association between N1 tumors and high levels of HA in cancer cells. Cox multivariate analysis showed significant association between better survival and low HA. HA increased in sputum from lung cancer patients compared to cancer-free and healthy volunteers and a significant correlation was found between HA in sputum and HA in cancer tissue. Localization of HA in tumor tissue was related to malignancy and reflected in sputum, making this an emerging factor for an important diagnostic procedure in patients suspected to have lung cancer. Further study in additional patients in a randomized prospective trial is required to finalize these results and to validate our quantitative assessment of HA, as well as to couple it to gold standard sputum cytology.


Subject(s)
Adult , Aged , Aged, 80 and over , Female , Humans , Male , Middle Aged , Carcinoma/chemistry , Hyaluronic Acid/analysis , Lung Neoplasms/chemistry , Sputum/chemistry , Biopsy , Biomarkers, Tumor/analysis , Case-Control Studies , Carcinoma/pathology , Enzyme-Linked Immunosorbent Assay , Immunohistochemistry , Lung Neoplasms/pathology , Lung/chemistry , Lung/pathology , Neoplasm Staging , Reproducibility of Results , Risk Factors , Sensitivity and Specificity , Statistics, Nonparametric , Smoking/adverse effects , Stromal Cells/chemistry , Stromal Cells/pathology
7.
Arq. bras. med. vet. zootec ; 66(4): 1281-1286, 08/2014. graf
Article in Portuguese | LILACS, VETINDEX | ID: biblio-1096013

ABSTRACT

Morphometry and ultrasound of carcasses were used to estimate the growth curve of Criola Lageana cows, raised under natural conditions. A total of 111 cows, raised under extensively production system in Central Plateau of Santa Catarina, were evaluated. Morphometrics and ultrasound measurements were related with the age of the animals using the targeted univariate regression model, assigning the variable response to gamma distribution. The inflection points of the growth curve were 24 and 25 months for withers height and hip height, between 27 and 29 for weight, body length, rump length, thorax perimeter, depth and distance between ilea. For ribeye area (REA), inflection point was 18 months. The Crioula Lageana cows presented greater growth velocity around 27 months, showing good productive performance under the natural conditions of the Central Plateau of Santa Catarina.(AU)


Subject(s)
Animals , Female , Cattle , Body Weights and Measures , Weight Gain , Growth and Development
8.
Braz. j. med. biol. res ; 47(7): 567-575, 07/2014. tab, graf
Article in English | LILACS | ID: lil-712970

ABSTRACT

Limitations on tissue proliferation capacity determined by telomerase/apoptosis balance have been implicated in pathogenesis of idiopathic pulmonary fibrosis. In addition, collagen V shows promise as an inductor of apoptosis. We evaluated the quantitative relationship between the telomerase/apoptosis index, collagen V synthesis, and epithelial/fibroblast replication in mice exposed to butylated hydroxytoluene (BHT) at high oxygen concentration. Two groups of mice were analyzed: 20 mice received BHT, and 10 control mice received corn oil. Telomerase expression, apoptosis, collagen I, III, and V fibers, and hydroxyproline were evaluated by immunohistochemistry, in situ detection of apoptosis, electron microscopy, immunofluorescence, and histomorphometry. Electron microscopy confirmed the presence of increased alveolar epithelial cells type 1 (AEC1) in apoptosis. Immunostaining showed increased nuclear expression of telomerase in AEC type 2 (AEC2) between normal and chronic scarring areas of usual interstitial pneumonia (UIP). Control lungs and normal areas from UIP lungs showed weak green birefringence of type I and III collagens in the alveolar wall and type V collagen in the basement membrane of alveolar capillaries. The increase in collagen V was greater than collagens I and III in scarring areas of UIP. A significant direct association was found between collagen V and AEC2 apoptosis. We concluded that telomerase, collagen V fiber density, and apoptosis evaluation in experimental UIP offers the potential to control reepithelization of alveolar septa and fibroblast proliferation. Strategies aimed at preventing high rates of collagen V synthesis, or local responses to high rates of cell apoptosis, may have a significant impact in pulmonary fibrosis.


Subject(s)
Animals , Male , Apoptosis/physiology , Collagen Type V/biosynthesis , Idiopathic Pulmonary Fibrosis/pathology , Pulmonary Fibrosis/pathology , Telomerase/metabolism , Butylated Hydroxytoluene , Cell Proliferation , Collagen Type I/analysis , Collagen Type II/analysis , Collagen Type V/analysis , Disease Models, Animal , Epithelial Cells/metabolism , Epithelial Cells/pathology , Fluorescent Antibody Technique , Fibroblasts/metabolism , Fibroblasts/pathology , Hydroxyproline/analysis , Immunohistochemistry , In Situ Nick-End Labeling , Mice, Inbred BALB C , Microscopy, Electron , Pulmonary Alveoli/pathology , Pulmonary Alveoli/ultrastructure , Staining and Labeling , Telomerase/isolation & purification
9.
Arq. bras. med. vet. zootec ; 64(6): 1449-1455, Dec. 2012. ilus
Article in Portuguese | LILACS | ID: lil-660209

ABSTRACT

Com o objetivo de avaliar a concentração plasmática de diclofenaco sódico (DS) emulgel em cães com ou sem o uso de fonoforese e de verificar se a fonoforese induz à maior absorção desse fármaco, foram utilizados cinco cães, e todos eles passaram por oito grupos distintos. Um grupo recebeu, via oral, um comprimido de DS, 40mg, por animal, e sete grupos receberam aplicação transdérmica de diclofenaco sódico emulgel por ultrassom. Pela via transdérmica, a área de aplicação era de 20cm². A frequência do ultrassom foi de 1MHz, modo contínuo, com intensidade de 0,4Wcm-2. Colheram-se amostras de sangue antes de se executarem os protocolos - tempo zero -, após uma hora - tempo 1 - e após quatro horas da aplicação - tempo 2 - em todos os grupos, e realizou-se análise das amostras por cromatografia líquida de alta eficiência. Houve diferença (P<0,05) apenas nas amostras no tempo 1 do grupo que recebeu dose oral de DS em relação às outras amostras. Não foi possível verificar concentração plasmática de diclofenaco sódico com aplicação tópica em cães submetidos ou não à fonoforese, apenas quantificou-se o diclofenaco sódico pela administração via oral. A facilitação da penetração transdérmica pelo ultrassom não foi verificada sob o protocolo especificado nesta pesquisa.


The aim of this study was to evaluate the plasma concentration of diclofenac sodium (DS) in dogs submitted to diclofenaco phonophoresis and to evaluate if phonophoresis induces greater absorption of this drug in dogs. Five dogs were used in eight different groups at different times: One group received oral administration of 40mg of DS per dog and seven groups received topical application of emulgel DS. The topical application area was 20cm². A continuous ultrasound frequency of 1MHz and intensity of 0.4W cm-2 was used. Blood collections were performed before the treatment (T0), and 1h (T1) and 4h (T2) after ultrasound application for all groups. DS concentrations in plasma were measured by high performance liquid choramatohraphy (HPLC). There was significant increase of DS plasma concentration only at T1 in the oral administration group. It was not possible to detect any concentration of DS in the plasma of dogs after topical application of DS, even after DS phonophoresis. The facilitation of transdermal penetration by ultrasound has not been verified under the protocol specified in this research.


Subject(s)
Animals , Dogs , Absorption , Absorption/radiation effects , Diclofenac/administration & dosage , Phonophoresis/veterinary , Cell Membrane , Cell Membrane , Administration, Cutaneous , Administration, Oral , Chromatography, High Pressure Liquid/veterinary , Ultrasonics
10.
Braz. j. med. biol. res ; 38(1): 11-15, Jan. 2005. ilus, tab
Article in English | LILACS | ID: lil-405534

ABSTRACT

Cystic fibrosis (CF) is the most common genetic disease among Caucasians and is rare among sub-Saharan Africans. The Brazilian population is not ethnically homogeneous but it is the result of three-way ethnic admixture of Europeans, Africans and Amerindians in varying proportions, depending on the region. In the present study, we investigated 33 patients who had been diagnosed and are currently under treatment for CF at the University Hospital João de Barros Barreto, Belém, Pará State. The molecular analysis for G542X, G551D and R553X mutations was performed by PCR followed by RFLP using BstNI, HincII and MboI, respectively, in polyacrylamide gel eletrophoresis and stained with AgNO3. ThedeltaF508 mutation (a deletion of 3 bp) was only analyzed by polyacrylamide gel electrophoresis and stained with AgNO3. Each sample was analyzed for regions of interest in the CFTR gene using amplified by PCR and specific primers. The deltaF508 and G551D mutations presented frequencies of 22.7 and 3 percent, respectively. In 74.3 percent of the remaining patients, none of the mutations investigated was found. The present study characterized in a sample of patients with an established clinical diagnosis of CF (asthma, repeated bronchopneumonia, disorders of nutritional status, etc.) the most frequent mutation ( deltaF508) in the North region of Brazil and is also the first report of the G551D mutation. In spite of the wide spectrum of CF mutations and the heterogeneous ethnic origin of the Amazon population, the molecular diagnosis is a helpful additional tool for the diagnosis and treatment of CF patients.


Subject(s)
Humans , Cystic Fibrosis Transmembrane Conductance Regulator/genetics , Cystic Fibrosis/genetics , Mutation , Brazil , Electrophoresis, Polyacrylamide Gel , Genetic Markers/genetics , Polymerase Chain Reaction , Polymorphism, Restriction Fragment Length , Prevalence
11.
Braz. j. med. biol. res ; 37(10): 1463-1472, Oct. 2004. ilus, mapas, tab
Article in English | LILACS | ID: lil-383031

ABSTRACT

Leaf-cutting ants of the genera Atta and Acromyrmex (tribe Attini) are symbiotic with basidiomycete fungi of the genus Leucoagaricus (tribe Leucocoprineae), which they cultivate on vegetable matter inside their nests. We determined the variation of the 28S, 18S, and 5.8S ribosomal DNA (rDNA) gene loci and the rapidly evolving internal transcribed spacers 1 and 2 (ITS1 and ITS2) of 15 sympatric and allopatric fungi associated with colonies of 11 species of leafcutter ants living up to 2,600 km apart in Brazil. We found that the fungal rDNA and ITS sequences from different species of ants were identical (or nearly identical) to each other, whereas 10 GenBank Leucoagaricus species showed higher ITS variation. Our findings suggest that Atta and Acromyrmex leafcutters living in geographic sites that are very distant from each other cultivate a single fungal species made up of closely related lineages of Leucoagaricus gongylophorus. We discuss the strikingly high similarity in the ITS1 and ITS2 regions of the Atta and Acromyrmex symbiotic L. gongylophorus studied by us, in contrast to the lower similarity displayed by their non-symbiotic counterparts. We suggest that the similarity of our L. gongylophorus isolates is an indication of the recent association of the fungus with these ants, and propose that both the intense lateral transmission of fungal material within leafcutter nests and the selection of more adapted fungal strains are involved in the homogenization of the symbiotic fungal stock.


Subject(s)
Animals , Ants , DNA, Ribosomal Spacer , Fungi , Symbiosis , Brazil , Genetic Variation , Plant Leaves , Polymerase Chain Reaction , Sequence Analysis, DNA
12.
Arq. bras. med. vet. zootec ; 56(2): 157-167, abr. 2004. ilus, tab
Article in English | LILACS | ID: lil-360678

ABSTRACT

Foram avaliadas as diferenças morfológicas e a participação da apoptose na população de células do placentoma de vacas das raças Holandesa e Nelore no período periparto. Foram utilizadas 22 vacas da raça Holandesa com parto a termo (tratamento I) e 10 com parto induzido (tratamento II). Nos tratamentos III e IV foram utilizadas 10 vacas Nelore com parto a termo e 21 com parto induzido, respectivamente. As células binucleadas trofoblásticas e epiteliais carunculares e os corpos apoptóticos foram quantificadas por microscopia óptica. A apoptose também foi avaliada por microscopia eletrônica de transmissão, ELISA e determinação da fragmentação do DNA por eletroforese em gel de agarose. O número de células epitelilais carunculares não variou entre as raças com parto normal ou induzido. O número de células binucleadas diferiu entre raças com parto a termo (tratamentos I e III); contudo seu número não variou quando o parto foi induzido. Em vacas com parto a termo a intensidade da apoptose foi significativamente maior no tratamento I do que no III, pela avaliação morfométrica e por ELISA. Entretanto, não foi encontrada diferença entre os tratamentos II e IV. A característica da fragmentação de DNA para a apoptose em eletroforese foi identificada pela presença de bandas com 200 pares de bases ou múltiplos. As características da apoptose no epitélio materno e fetal e no endotélio vascular foram identificadas por microscopia eletrônica de transmissão. Os resultados permitem concluir que em vacas Nelore a maturação da placenta ocorre precocemente quando comparada à da raça Holandesa e que em ambas as raças a apoptose é um evento fisiológico ativo na maturação e eliminação da placenta.


Subject(s)
Animals , Apoptosis , Horses , Placenta
13.
Braz. j. med. biol. res ; 34(5): 585-595, May 2001.
Article in English | LILACS | ID: lil-285872

ABSTRACT

Prions have been extensively studied since they represent a new class of infectious agents in which a protein, PrPsc (prion scrapie), appears to be the sole component of the infectious particle. They are responsible for transmissible spongiform encephalopathies, which affect both humans and animals. The mechanism of disease propagation is well understood and involves the interaction of PrPsc with its cellular isoform (PrPc) and subsequently abnormal structural conversion of the latter. PrPc is a glycoprotein anchored on the cell surface by a glycosylphosphatidylinositol moiety and expressed in most cell types but mainly in neurons. Prion diseases have been associated with the accumulation of the abnormally folded protein and its neurotoxic effects; however, it is not known if PrPc loss of function is an important component. New efforts are addressing this question and trying to characterize the physiological function of PrPc. At least four different mouse strains in which the PrP gene was ablated were generated and the results regarding their phenotype are controversial. Localization of PrPc on the cell membrane makes it a potential candidate for a ligand uptake, cell adhesion and recognition molecule or a membrane signaling molecule. Recent data have shown a potential role for PrPc in the metabolism of copper and moreover that this metal stimulates PrPc endocytosis. Our group has recently demonstrated that PrPc is a high affinity laminin ligand and that this interaction mediates neuronal cell adhesion and neurite extension and maintenance. Moreover, PrPc-caveolin-1 dependent coupling seems to trigger the tyrosine kinase Fyn activation. These data provide the first evidence for PrPc involvement in signal transduction


Subject(s)
Humans , Animals , Mice , Membrane Proteins/physiology , Prion Diseases/physiopathology , PrPC Proteins/physiology , Copper/metabolism , Endocytosis , Laminin/physiology , Ligands , Membrane Proteins/genetics , Phenotype , PrPC Proteins/genetics , PrPC Proteins/isolation & purification , PrPSc Proteins/genetics
14.
Genet. mol. biol ; 24(1/4): 169-174, 2001. ilus, tab
Article in English | LILACS | ID: lil-313887

ABSTRACT

Com o propósito de determinar a relaçäo filogenética entre a cana-de-açúcar e membros da subtribo Saccharinae,a regiäo gênica nuclear ITS1-5,8S-ITS2 (ITS: espaçador interno transcrito; 5,8S: DNA ribossomal 5.8S), com alta taxa evolutiva, foi identificada no banco de dados do projeto genoma "Sugarcane Expressed Sequence Tag" (SUCEST). Uma análise através do método de parcimônia, utilizando esta regiäo e seqüências homólogas de 23 Andropogoneae retiradas da base de dados GenBank, indicou que a cana-de-açúcar é o grupo-irmäo de Saccharum sinense. No entanto, devido à pequena quantidade de caracteres informativos para parcimônia e à homoplasia presentes na regiäo ITS1-5,8S-ITS2, näo foi possível determinar com segurança a relaçäo filogenética entre a cana-de-açúcar e alguns dos demais membros da tribo Saccharine. Como alternativa para esta baixa resoluçäo, dezessete regiões gênicas nucleares, cloroplasmáticas ou mitocondriais foram selecionadas a partir do banco de dados SUCEST com o objetivo de encontrar marcadores mais apropriados para a reconstruçäo da filogenia da cana-de-açúcar. Entre elas, aquelas correspondentes à alfa-tubulina, rpl16, a rpoC2 apresentaram baixa incidência de polimorfismo e taxas de evoluçäo equivalentes ou mesmo maiores do que a observada para a regiäo ITS1-5,8S-ITS2. Estes marcadores säo propostos como preferenciais para estudos filogenéticos da subtribo Saccharinae.


Subject(s)
Expressed Sequence Tags , Phylogeny , Plants , Databases as Topic
15.
Braz. j. med. biol. res ; 32(7): 853-9, July 1999.
Article in English | LILACS | ID: lil-234891

ABSTRACT

Prions are an unconventional form of infectious agents composed only of protein and involved in transmissible spongiform encephalopathies in humans and animals. The infectious particle is composed by PrPsc which is an isoform of a normal cellular glycosyl-phosphatidylinositol (GPI) anchored protein, PrPc, of unknown function. The two proteins differ only in conformation, PrPc is composed of 40 percent helix while PrPsc has 60 percent ß-sheet and 20 percent helix structure. The infection mechanism is trigged by interaction of PrPsc with cellular prion protein causing conversion of the latter's conformation. Therefore, the infection spreads because new PrPsc molecules are generated exponentially from the normal PrPc. The accumulation of insoluble PrPsc is probably one of the events that lead to neuronal death. Conflicting data in the literature showed that PrPc internalization is mediated either by clathrin-coated pits or by caveolae-like membranous domains. However, both pathways seem to require a third protein (a receptor or a prion-binding protein) either to make the connection between the GPI-anchored molecule to clathrin or to convert PrPc into PrPsc. We have recently characterized a 66-kDa membrane receptor which binds PrPc in vitro and in vivo and mediates the neurotoxicity of a human prion peptide. Therefore, the receptor should have a role in the pathogenesis of prion-related diseases and in the normal cellular process. Further work is necessary to clarify the events triggered by the association of PrPc/PrPsc with the receptor


Subject(s)
Mice , Humans , Animals , Cricetinae , Prion Diseases/metabolism , Receptors, Cell Surface/metabolism , PrPC Proteins/analysis , PrPC Proteins/metabolism , PrPSc Proteins/analysis , PrPSc Proteins/metabolism
16.
Arq. bras. cardiol ; 69(6): 401-5, dez. 1997. ilus, tab, graf
Article in Portuguese | LILACS | ID: lil-234373

ABSTRACT

OBJETIVO - Relatar experiência no emprego de altas doses de amiodarona via oral (1800mg/d) na reversão da fibrilação atrial (FA) em pacientes submetidos à cirurgia cardíaca. MÉTODOS - Analisados, retrospectivamente, 80 pacientes, que apresentaram FA no pós operatório de cirurgia cardíaca, constituindo 2 grupos: grupo A com 28 pacientes em uso de amiodarona e grupo B recebendo digital, sendo que este grupo foi subdividido no grupo C com 21 pacientes onde foi associada amiodarona, quando não houvesse reversão da arritmia em 48h. As diferenças foram consideradas significativas para um valor de P<0,05. RESULTADOS - A FA esteve presente em 19,4 'por cento' dos pacientes operados, com predomínio no sexo masculino e entre 60-69 anos. No grupo A, a reversão ocorreu em 78,6 'por cento' dos casos, grupo B, o digital obteve sucesso em 60 'por cento' das vezes e no grupo C, a taxa de sucesso foi de 90 'por cento'. CONCLUSÄO - O uso de altas doses de amiodarona via oral, isolada ou em combinação com digital pode ser segura e eficaz no tratamento da FA em pós operatório de cirurgia cardíaca.


Subject(s)
Humans , Male , Middle Aged , Amiodarone/administration & dosage , Atrial Fibrillation/therapy , Epidemiology, Descriptive , Postoperative Care , Prevalence , Retrospective Studies , Thoracic Surgery
17.
Rev. bras. ortop ; 32(3): 249-53, mar. 1997. ilus, tab
Article in Portuguese | LILACS | ID: lil-209248

ABSTRACT

Os autores estudaram as medidas biométricas de nove tálus de sete pacientes portadores de artrogripose múltipla congênita com as de nove tálus de oito pacientes com pé eqüinovaro congênito idiopático. Como grupo-controle foram utilizados 12 tálus de seis cadáveres humanos adultos sem deformidades aparentes. Foram avaliados o comprimento, a altura média do corpo, o formato da tróclea, os ângulos do colo com o corpo talar nos planos horizontal e sagital e o peso. Após análise estatística, demonstraram que o tálus no pé artrogripótico tem menor peso, a tróclea menos deformada e o colo menos desviado medialmente que no pé eqüinovaro idiopático.


Subject(s)
Humans , Male , Female , Adult , Middle Aged , Arthrogryposis , Biometry , Foot Deformities , Talipes , Talus/anatomy & histology , Statistics, Nonparametric
20.
An. farm. quím. Säo Paulo ; 26/28: 57-77, 1988. tab
Article in Portuguese | LILACS | ID: lil-76844

ABSTRACT

O presente estudo foi realizado com a finalidade de analisar receptores de glicocorticóide em leucócitos mononucleares (MNL) de sangue periférico de indivíduos normais, näo tratados e de indivíduos normal aos quais foram administrados exogenamente os corticóides: prednisona e deflazacort. MNL de mulheres e homens normais apresentaram uma concentraçäo de receptores de glicocorticóide de 7,52 ñ 2,5fMol/10**6 cel e uma constante de dissociaçäo (Kd) de 9,5 ñ 2,3nM. Näo houve diferença em relaçäo ao sexo e as fases do ciclo menstrual. Em indivíduos tratados com predinisona, näo houve mudança nos parâmetros de ligaçäo. A administraçäo deflazacort determinou uma sensível reduçäo dos sítios de ligaçäo. Concluímos que certos glicocorticóides podem exercer um efeito regulatório sobre seus receptores


Subject(s)
Adolescent , Adult , Middle Aged , Humans , Male , Female , Leukocytes, Mononuclear/analysis , Prednisone/blood , Pregnenediones/blood , Receptors, Glucocorticoid/analysis
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