Time filter

Source Type

Lazoski C.,Institute Biologia | Gusmao J.,Institute Biologia | Gusmao J.,Institute Biologia Roberto Alcantara Gomes | Boudry P.,French Research Institute for Exploitation of the Sea | Sole-Cava A.M.,Institute Biologia
Marine Ecology Progress Series | Year: 2011

The phylogenetic relationships between naturally occurring Atlantic Crassostrea oyster species were inferred through analyses of mitochondrial (cytochrome oxidase subunit I and 16S) and nuclear (second internal transcribed spacer) sequences. We also scored 15 allozyme loci on 422 oysters to study population structuring of C. rhizophorae and C. brasiliana along 9000 km of the Western Atlantic coastline. Despite morphological similarities, C. virginica was genetically more closely related to C. rhizophorae than to C. brasiliana. In contrast, C. paraibanensis was genetically indistinguishable from C. brasiliana, which is probably a junior synonym of the African C. gasar. Significant genetic differentiation between populations of C. rhizophorae and C. gasar were found along the Western Atlantic coast, supporting an isolation-by-distance pattern. © 2011 Inter-Research.


Tavares C.,Institute Biologia Roberto Alcantara Gomes | Tavares C.,State University of Rio de Janeiro | Gusmao J.,Institute Biologia Roberto Alcantara Gomes
Zootaxa | Year: 2016

The pink shrimp, Farfantepenaeus subtilis, actually comprises two cryptic species confused under a single name. Despite morphological and molecular evidences accumulated since 1967, the new species confused with F. subtilis has never been formally described. In this paper, Farfantepenaeus isabelae sp. nov., is described and compared to its close relatives, F. brasiliensis, F. notialis, F. paulensis and F. subtilis s. str. © 2016 Magnolia Press.


Filgueiras C.C.,State University of Rio de Janeiro | Filgueiras C.C.,Institute Biologia Roberto Alcantara Gomes | Pohl-Guimaraes F.,Virginia Commonwealth University | Krahe T.E.,Virginia Commonwealth University | And 2 more authors.
Pharmacology Biochemistry and Behavior | Year: 2013

The brain is extremely vulnerable to teratogenic insults during the brain growth spurt, a period that starts during the third trimester of human gestation and is characterized by synaptogenesis establishment of neuronal circuits. While the treatment of epilepsy during pregnancy increases the risk of neurodevelopmental disorders in offspring, the consequences of exposure to anticonvulsants during the brain growth spurt remain poorly known. Here we investigate whether exposure to sodium valproate (VPA) during a similar period in rats impairs spatial learning of juvenile rats. Long-Evans rats were exposed to VPA (200 mg/kg) or saline solution (SAL) every other day between postnatal day (PN) 4 and PN10. At PN23 and PN30, Morris water maze performance was evaluated during 6 consecutive days. In the group of animals which started their tests at PN23, the VPA exposure impaired both, swimming speed and learning/memory performance. Interestingly, no differences were observed between VPA and control animals tested from PN30 to PN35. Our data suggests that the neurobehavioral deficits caused by VPA exposure during the brain growth spurt are transitory. © 2012 Elsevier Inc. All rights reserved.


PubMed | Institute Biofisica Carlos Chagas Filho and Institute Biologia Roberto Alcantara Gomes
Type: Journal Article | Journal: Journal of microscopy | Year: 2016

Some chemotherapeutic agents used for breast cancer (BC) treatment can induce severe side effects in the ovarian tissue. The combination of cyclophosphamide and docetaxel (TC) is widely used for BC treatment; however, its late effects in the ovary are not completely understood. The main purpose of this study was to evaluate the structural and ultrastructural alterations in the ovarian stroma induced by TC treatment. Wistar rats were divided into two groups: a control group and a TC group. They were euthanized 5 months after the end of treatment, and their plasma and ovaries were collected. Important alterations were noted. The serum estradiol level was significantly reduced in the TC group compared with the control group. Additionally, the number of apoptotic nuclei was higher in the TC group. The role of the inflammatory response in the development of ovarian damage was investigated, and we found an increased number of mast cells and increased expression of TNF- in the TC group. The involvement of fibrosis was also investigated. The results showed that the TC group had increased expression levels of TGF-1, collagen type I (col-I) and collagen type III (col-III) compared with the control group. Ultrastructural analysis revealed the presence of collagen fibrils in the treated group and illustrated that the ovarian tissue architecture was more disorganized in this group than in the control group. The results from this study are important in the study of chemotherapy-induced ovarian failure and provide further insight into the mechanisms involved in the development of this disease.


PubMed | Federal University of Juiz de fora and Institute Biologia Roberto Alcantara Gomes
Type: | Journal: Brazilian journal of medical and biological research = Revista brasileira de pesquisas medicas e biologicas | Year: 2015

Semiconductor laser devices are readily available and practical radiation sources providing wavelength tenability and high monochromaticity. Low-intensity red and near-infrared lasers are considered safe for use in clinical applications. However, adverse effects can occur via free radical generation, and the biological effects of these lasers from unusually high fluences or high doses have not yet been evaluated. Here, we evaluated the survival, filamentation induction and morphology of Escherichia coli cells deficient in repair of oxidative DNA lesions when exposed to low-intensity red and infrared lasers at unusually high fluences. Cultures of wild-type (AB1157), endonuclease III-deficient (JW1625-1), and endonuclease IV-deficient (JW2146-1) E. coli, in exponential and stationary growth phases, were exposed to red and infrared lasers (0, 250, 500, and 1000 J/cm2) to evaluate their survival rates, filamentation phenotype induction and cell morphologies. The results showed that low-intensity red and infrared lasers at high fluences are lethal, induce a filamentation phenotype, and alter the morphology of the E. coli cells. Low-intensity red and infrared lasers have potential to induce adverse effects on cells, whether used at unusually high fluences, or at high doses. Hence, there is a need to reinforce the importance of accurate dosimetry in therapeutic protocols.


PubMed | Federal University of Juiz de fora and Institute Biologia Roberto Alcantara Gomes
Type: Journal Article | Journal: Brazilian journal of medical and biological research = Revista brasileira de pesquisas medicas e biologicas | Year: 2015

Low-intensity lasers are used for prevention and management of oral mucositis induced by anticancer therapy, but the effectiveness of treatment depends on the genetic characteristics of affected cells. This study evaluated the survival and induction of filamentation of Escherichia coli cells deficient in the nucleotide excision repair pathway, and the action of T4endonuclease V on plasmid DNA exposed to low-intensity red and near-infrared laser light. Cultures of wild-type (strain AB1157) E. coli and strain AB1886 (deficient in uvrA protein) were exposed to red (660 nm) and infrared (808 nm) lasers at various fluences, powers and emission modes to study bacterial survival and filamentation. Also, plasmid DNA was exposed to laser light to study DNA lesions produced in vitro by T4endonuclease V. Low-intensity lasers:i) had no effect on survival of wild-type E. coli but decreased the survival of uvrA protein-deficient cells,ii) induced bacterial filamentation, iii) did not alter the electrophoretic profile of plasmids in agarose gels, andiv) did not alter the electrophoretic profile of plasmids incubated with T4 endonuclease V. These results increase our understanding of the effects of laser light on cells with various genetic characteristics, such as xeroderma pigmentosum cells deficient in nucleotide excision pathway activity in patients with mucositis treated by low-intensity lasers.


PubMed | Centro Universitario Serra dos =rgaos, Federal University of Juiz de fora and Institute Biologia Roberto Alcantara Gomes
Type: Journal Article | Journal: Brazilian journal of medical and biological research = Revista brasileira de pesquisas medicas e biologicas | Year: 2015

Low-level lasers are used at low power densities and doses according to clinical protocols supplied with laser devices or based on professional practice. Although use of these lasers is increasing in many countries, the molecular mechanisms involved in effects of low-level lasers, mainly on DNA, are controversial. In this study, we evaluated the effects of low-level red lasers on survival, filamentation, and morphology of Escherichia colicells that were exposed to ultraviolet C (UVC) radiation. Exponential and stationary wild-type and uvrA-deficientE. coli cells were exposed to a low-level red laser and in sequence to UVC radiation. Bacterial survival was evaluated to determine the laser protection factor (ratio between the number of viable cells after exposure to the red laser and UVC and the number of viable cells after exposure to UVC). Bacterial filaments were counted to obtain the percentage of filamentation. Area-perimeter ratios were calculated for evaluation of cellular morphology. Experiments were carried out in duplicate and the results are reported as the means of three independent assays. Pre-exposure to a red laser protected wild-type and uvrA-deficient E. coli cells against the lethal effect of UVC radiation, and increased the percentage of filamentation and the area-perimeter ratio, depending on UVC fluence and physiological conditions in the cells. Therapeutic, low-level red laser radiation can induce DNA lesions at a sub-lethal level. Consequences to cells and tissues should be considered when clinical protocols based on this laser are carried out.


PubMed | Federal University of Juiz de fora and Institute Biologia Roberto Alcantara Gomes
Type: Journal Article | Journal: Brazilian journal of medical and biological research = Revista brasileira de pesquisas medicas e biologicas | Year: 2015

Semiconductor laser devices are readily available and practical radiation sources providing wavelength tenability and high monochromaticity. Low-intensity red and near-infrared lasers are considered safe for use in clinical applications. However, adverse effects can occur via free radical generation, and the biological effects of these lasers from unusually high fluences or high doses have not yet been evaluated. Here, we evaluated the survival, filamentation induction and morphology of Escherichia coli cells deficient in repair of oxidative DNA lesions when exposed to low-intensity red and infrared lasers at unusually high fluences. Cultures of wild-type (AB1157), endonuclease III-deficient (JW1625-1), and endonuclease IV-deficient (JW2146-1) E. coli, in exponential and stationary growth phases, were exposed to red and infrared lasers (0, 250, 500, and 1000 J/cm2) to evaluate their survival rates, filamentation phenotype induction and cell morphologies. The results showed that low-intensity red and infrared lasers at high fluences are lethal, induce a filamentation phenotype, and alter the morphology of the E. coli cells. Low-intensity red and infrared lasers have potential to induce adverse effects on cells, whether used at unusually high fluences, or at high doses. Hence, there is a need to reinforce the importance of accurate dosimetry in therapeutic protocols.


Callado C.H.,Institute Biologia Roberto Alcantara Gomes | Barros C.F.,Institute Pesquisas Jardim Botanico Do Rio Of Janeiro | Costa M.S.,Institute Biologia Roberto Alcantara Gomes | De Vasconcellos T.J.,Institute Biologia Roberto Alcantara Gomes
IAWA Journal | Year: 2013

This study is aimed to understand responses in growth rhythm to different climatic conditions of the widespread deciduous species Cedrela odorata. Our own research was conducted in Nova Iguaçu. Rio de Janeiro State, Brazil) and compared with literature data from Aripuanã. Mato Grosso State, Brazil), Manaus. Amazonas State, Brazil) and Barinas. Barinas State, Venezuela). Growth periodicity was evaluated through leaf phenological behavior and radial growth. In Nova Iguaçu, leaf phenology was monitored monthly and radial growth was evaluated by cambial histological analysis of samples collected in wet and dry seasons. In the other sites, the authors evaluated the growth rhythm by dendrometer bands. Growth always occurs in the wet season, even when there is no water deficit during the dry season. Thus, the species is considered conservative concerning the maintenance of growth seasonality. Nevertheless, C. odorata was able to change its growth period, following local seasonality of its different growth sites. Therefore we suggest caution when performing climate analysis from a chronology using trees that grow in different periods of the year. © International Association of Wood Anatomists, 2013.


PubMed | Institute Biologia Roberto Alcantara Gomes
Type: Journal Article | Journal: Journal of biosciences | Year: 2016

Laser used to stimulate acupoints is called laser acupuncture (LA). It is generally believed that similar clinical responses to manual acupuncture can be achieved. Here we analysed the effects of the laser (904 nm) at the Zusanli acupoint (ST.36) of the stomach meridian on the biodistribution of the radiopharmaceutical Na(99m)TcO4. Wistar rats were divided into control (CG) and experimental groups (EG). The EG were exposed daily to the laser (904 nm) at ST.36 with 1 joule/min (40 mW/cm(2)) for 1 min. The animals of the CG were not exposed to laser at all. On the 8th day after LA, the animals were sedated and Na(99m)TcO4 was administered. After 10 min, the animals were all sacrificed and the organs removed. The radioactivity was counted in each organ to calculate the percentage of radioactivity of the injected dose per gram (%ATI/ g). Comparison of the %ATI/g in EG and CG was performed by Mann-Whitney test. The %ATI/g was significantly increased in the thyroid due to the stimulation of the ST.36 by laser. It is possible to conclude that the stimulation of ST.36 does lead to biological phenomena that interfere with the metabolism of the thyroid.

Loading Institute Biologia Roberto Alcantara Gomes collaborators
Loading Institute Biologia Roberto Alcantara Gomes collaborators