As aneuploidias constituem a principal alteracao genetica encontrada na especie humana e podem en... more As aneuploidias constituem a principal alteracao genetica encontrada na especie humana e podem envolver tanto cromossomos autossomicos quanto sexuais. As neuploidias em mosaicos sao menos frequentes do que as trissomias livres, podendo apresentar-se, do ponto de vista clinico, de forma bastante heterogenea. O mosaicismo acontece devido ao surgimento de uma segunda linhagem celular (trissomica ou dissomica) durante o periodo pos-zigotico. A tecnica de FISH em nucleo interfasico tem sido descrita como mais sensivel na deteccao de mosaicismos, por prescindir do cultivo celular e por possibilitar a analise de um grande numero de celulas de cada vez. Neste trabalho utilizou-se a citogenetica convencional e a do FISH interfasico, em 3 grupos de individuos: 1) 10 pacientes com mosaicismo cromossomico conhecido (3 mosaicos tetraploides-diploides, 1 mosaico do cromossomo 15, 1 mosaico do cromossomo 14, 1 mosaico de cromossomo marcador e 4 casos de mosaicos do cromossomo 21); 2) 9 pacientes p...
... Em 1793, foi para o acervo do museu do Louvre e em 1911 foi roubada. O quadro reapa-receu ano... more ... Em 1793, foi para o acervo do museu do Louvre e em 1911 foi roubada. O quadro reapa-receu anos depois na Itália, pelas mãos de um pintor nacionalista que quis devolver a obra à sua pátria de origem. Foi este episódio que trou-xe grande fama à Gioconda. Ingrid Lemos ...
Chimerism is rare in humans and is usually discovered accidentally when a 46,XX and 46,XY karyoty... more Chimerism is rare in humans and is usually discovered accidentally when a 46,XX and 46,XY karyotype is found in a same individual. We describe a malformed female infant with neural tube defect (NTD) and a 47,XY,+21[5]/46,XX[30] karyotype.
The central objective of this study was to assess solar radiation-induced changes in cellular fun... more The central objective of this study was to assess solar radiation-induced changes in cellular function, mitochondrial function and mitochondrial DNA to further investigate the role of these energy-dedicated and metabolically essential organelles in the response to the main environmental stressor associated with skin cancer initiation. An in vitro approach was chosen employing the human malignant melanoma (A375) and human amelanotic melanoma (C32) cells and the human spontaneously immortalized keratinocytes (HaCaT). A Q-Sun Solar Simulator was used to expose cells to low-level simulated solar radiation (SSR) as it provides a mimic of solar radiation that is environmentally relevant in the UV spectrum. Cell viability, apoptosis, DNA and protein content were analysed as cellular response end-points and they have been observed to change in a cell type-specific and time- dependent manner post SSR. Increases in mitochondrial genome number and mtDNA3895 were observed as an early response t...
To assess changes in mitochondrial morphology and mitophagy induced by simulated sunlight irradia... more To assess changes in mitochondrial morphology and mitophagy induced by simulated sunlight irradiation (SSI) and how these changes are modulated by mitochondrial activity and energy source. Human malignant amelanotic melanoma A375 cells were pre-treated with either a mitochondrial activity enhancer, uncoupler or were either melanin or glutamine supplemented/starved for 4 hours pre-exposure to sunlight. A Q-Sun Solar Simulator (Q-Lab, Homestead, FL, USA) was employed to expose cells to simulated sunlight. Confocal microscopy imaging of A375 cells co-loaded with mitochondria and lysosome-specific fluorescent dyes was used to identify these organelles and predict mitophagic events. SSI induces pronounced changes in mitochondrial dynamics and mitophagy in exposed skin cells compared to control and these effects were modified by both glutamine and melanin. Mitochondrial dynamics and rate of mitophagy in melanoma cells are sensitive to even short bursts of environmentally relevant SSI. Mitochondrial dynamics, and its modulation, may also play a role in mitophagy regulation, cell survival and proliferation post SSI.
The aim of this study was to describe clinical features and search for primary mitochondrial DNA ... more The aim of this study was to describe clinical features and search for primary mitochondrial DNA (mtDNA) mutations in 13 unrelated Brazilian patients with Leber's hereditary optic neuropathy (LHON). Analysis of the G11778A, G3460A, and T14484C mutations was done by polymerase chain reaction and restriction fragment length polymorphism, and mutations were confirmed by direct sequencing. Mean age of onset was 24.5 years and all cases were bilateral. Sex ratio (12M:1F) and frequency of simultaneous involvement (9/13) were higher than in other studies. In nine cases there was familial recurrence: 24 male and two female relatives. Ten patients had a mutation: G11778A in six, T14484C in three and one G3460A. The frequency of patients bearing a primary mutation was lower than that described in multicentric studies but similar to that observed among Asians. A higher frequency of the T14484C mutation was detected. The contribution of Amerindians and Africans to the Brazilian mtDNA pool may account for differences in the type and frequency of primary LHON mutations.
Solar ultraviolet radiation (UVR) is the principal etiological factor in skin carcinogenesis. In ... more Solar ultraviolet radiation (UVR) is the principal etiological factor in skin carcinogenesis. In vivo and in vitro studies have demonstrated previously that oxidative DNA damage, mitochondrial mass and mitochondrial membrane potential (MMP) changes are associated with skin cell response to UVR stress. Spontaneously immortalized human skin keratinocytes were irradiated with increasing sub-lethal doses of simulated sunlight irradiation (SSI) using a Q-Sun solar simulator. The effects of SSI on reactive oxygen species (ROS) formation, mitochondrial mass and MMP were then determined. SSI induced mitochondrial mass increase post low SSI (0.25-2.5 J/cm²), whereas higher SSI doses (5.0 and 7.5 J/cm²) decreased mitochondrial mass. Mitochondrial mass increased with time post 5.0 J/cm² irradiation and all changes in mass were independent of cell density status. Changes in ROS and MMP were cell density dependent. Additionally, an inverted dose-dependent decrease in ROS formation was observed 3...
... Send correspondence to Denise Pontes Cavalcanti. ... Am J Med Genet 65:160-166. Sawai T, Yosh... more ... Send correspondence to Denise Pontes Cavalcanti. ... Am J Med Genet 65:160-166. Sawai T, Yoshimoto M, Kinoshita E, Baba T, Matsumoto T, Tsuji Y, Fukuda S, Harada N and Niikawa N (1994) Case of 46,XX/47,XY,+21 chimerism in newborn infant with am-biguous genitalia. ...
We report tetraploid/diploid mosaicism in a boy and two girls detected by cultured skin fibroblas... more We report tetraploid/diploid mosaicism in a boy and two girls detected by cultured skin fibroblasts. In all these children, interphase-FISH using DXZ1 probe confirmed the original karyotype. Tetraploid mosaicism was also confirmed by alpha-satellite probes from chromosomes 2, 6, 7, 9, 10, 17, 18 and Y in fibroblasts from the boy. The common features in these children are failure to thrive, slight mental deficiency and some degree of body asymmetry. The advantage of using interphase-FISH is the possibility of analysing a great number of cells in short time, thus giving a more precise percentage with regard to abnormal cells.
As aneuploidias constituem a principal alteracao genetica encontrada na especie humana e podem en... more As aneuploidias constituem a principal alteracao genetica encontrada na especie humana e podem envolver tanto cromossomos autossomicos quanto sexuais. As neuploidias em mosaicos sao menos frequentes do que as trissomias livres, podendo apresentar-se, do ponto de vista clinico, de forma bastante heterogenea. O mosaicismo acontece devido ao surgimento de uma segunda linhagem celular (trissomica ou dissomica) durante o periodo pos-zigotico. A tecnica de FISH em nucleo interfasico tem sido descrita como mais sensivel na deteccao de mosaicismos, por prescindir do cultivo celular e por possibilitar a analise de um grande numero de celulas de cada vez. Neste trabalho utilizou-se a citogenetica convencional e a do FISH interfasico, em 3 grupos de individuos: 1) 10 pacientes com mosaicismo cromossomico conhecido (3 mosaicos tetraploides-diploides, 1 mosaico do cromossomo 15, 1 mosaico do cromossomo 14, 1 mosaico de cromossomo marcador e 4 casos de mosaicos do cromossomo 21); 2) 9 pacientes p...
... Em 1793, foi para o acervo do museu do Louvre e em 1911 foi roubada. O quadro reapa-receu ano... more ... Em 1793, foi para o acervo do museu do Louvre e em 1911 foi roubada. O quadro reapa-receu anos depois na Itália, pelas mãos de um pintor nacionalista que quis devolver a obra à sua pátria de origem. Foi este episódio que trou-xe grande fama à Gioconda. Ingrid Lemos ...
Chimerism is rare in humans and is usually discovered accidentally when a 46,XX and 46,XY karyoty... more Chimerism is rare in humans and is usually discovered accidentally when a 46,XX and 46,XY karyotype is found in a same individual. We describe a malformed female infant with neural tube defect (NTD) and a 47,XY,+21[5]/46,XX[30] karyotype.
The central objective of this study was to assess solar radiation-induced changes in cellular fun... more The central objective of this study was to assess solar radiation-induced changes in cellular function, mitochondrial function and mitochondrial DNA to further investigate the role of these energy-dedicated and metabolically essential organelles in the response to the main environmental stressor associated with skin cancer initiation. An in vitro approach was chosen employing the human malignant melanoma (A375) and human amelanotic melanoma (C32) cells and the human spontaneously immortalized keratinocytes (HaCaT). A Q-Sun Solar Simulator was used to expose cells to low-level simulated solar radiation (SSR) as it provides a mimic of solar radiation that is environmentally relevant in the UV spectrum. Cell viability, apoptosis, DNA and protein content were analysed as cellular response end-points and they have been observed to change in a cell type-specific and time- dependent manner post SSR. Increases in mitochondrial genome number and mtDNA3895 were observed as an early response t...
To assess changes in mitochondrial morphology and mitophagy induced by simulated sunlight irradia... more To assess changes in mitochondrial morphology and mitophagy induced by simulated sunlight irradiation (SSI) and how these changes are modulated by mitochondrial activity and energy source. Human malignant amelanotic melanoma A375 cells were pre-treated with either a mitochondrial activity enhancer, uncoupler or were either melanin or glutamine supplemented/starved for 4 hours pre-exposure to sunlight. A Q-Sun Solar Simulator (Q-Lab, Homestead, FL, USA) was employed to expose cells to simulated sunlight. Confocal microscopy imaging of A375 cells co-loaded with mitochondria and lysosome-specific fluorescent dyes was used to identify these organelles and predict mitophagic events. SSI induces pronounced changes in mitochondrial dynamics and mitophagy in exposed skin cells compared to control and these effects were modified by both glutamine and melanin. Mitochondrial dynamics and rate of mitophagy in melanoma cells are sensitive to even short bursts of environmentally relevant SSI. Mitochondrial dynamics, and its modulation, may also play a role in mitophagy regulation, cell survival and proliferation post SSI.
The aim of this study was to describe clinical features and search for primary mitochondrial DNA ... more The aim of this study was to describe clinical features and search for primary mitochondrial DNA (mtDNA) mutations in 13 unrelated Brazilian patients with Leber's hereditary optic neuropathy (LHON). Analysis of the G11778A, G3460A, and T14484C mutations was done by polymerase chain reaction and restriction fragment length polymorphism, and mutations were confirmed by direct sequencing. Mean age of onset was 24.5 years and all cases were bilateral. Sex ratio (12M:1F) and frequency of simultaneous involvement (9/13) were higher than in other studies. In nine cases there was familial recurrence: 24 male and two female relatives. Ten patients had a mutation: G11778A in six, T14484C in three and one G3460A. The frequency of patients bearing a primary mutation was lower than that described in multicentric studies but similar to that observed among Asians. A higher frequency of the T14484C mutation was detected. The contribution of Amerindians and Africans to the Brazilian mtDNA pool may account for differences in the type and frequency of primary LHON mutations.
Solar ultraviolet radiation (UVR) is the principal etiological factor in skin carcinogenesis. In ... more Solar ultraviolet radiation (UVR) is the principal etiological factor in skin carcinogenesis. In vivo and in vitro studies have demonstrated previously that oxidative DNA damage, mitochondrial mass and mitochondrial membrane potential (MMP) changes are associated with skin cell response to UVR stress. Spontaneously immortalized human skin keratinocytes were irradiated with increasing sub-lethal doses of simulated sunlight irradiation (SSI) using a Q-Sun solar simulator. The effects of SSI on reactive oxygen species (ROS) formation, mitochondrial mass and MMP were then determined. SSI induced mitochondrial mass increase post low SSI (0.25-2.5 J/cm²), whereas higher SSI doses (5.0 and 7.5 J/cm²) decreased mitochondrial mass. Mitochondrial mass increased with time post 5.0 J/cm² irradiation and all changes in mass were independent of cell density status. Changes in ROS and MMP were cell density dependent. Additionally, an inverted dose-dependent decrease in ROS formation was observed 3...
... Send correspondence to Denise Pontes Cavalcanti. ... Am J Med Genet 65:160-166. Sawai T, Yosh... more ... Send correspondence to Denise Pontes Cavalcanti. ... Am J Med Genet 65:160-166. Sawai T, Yoshimoto M, Kinoshita E, Baba T, Matsumoto T, Tsuji Y, Fukuda S, Harada N and Niikawa N (1994) Case of 46,XX/47,XY,+21 chimerism in newborn infant with am-biguous genitalia. ...
We report tetraploid/diploid mosaicism in a boy and two girls detected by cultured skin fibroblas... more We report tetraploid/diploid mosaicism in a boy and two girls detected by cultured skin fibroblasts. In all these children, interphase-FISH using DXZ1 probe confirmed the original karyotype. Tetraploid mosaicism was also confirmed by alpha-satellite probes from chromosomes 2, 6, 7, 9, 10, 17, 18 and Y in fibroblasts from the boy. The common features in these children are failure to thrive, slight mental deficiency and some degree of body asymmetry. The advantage of using interphase-FISH is the possibility of analysing a great number of cells in short time, thus giving a more precise percentage with regard to abnormal cells.
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