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1.
Braz J Med Biol Res ; 55: e12072, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35766708

RESUMO

Constitutional genomic imbalances are known to cause malformations, disabilities, neurodevelopmental delay, and dysmorphia and can lead to dysfunctions in the cell cycle. In extremely rare genetic conditions such as small supernumerary marker chromosomes (sSMC), it is important to understand the cellular consequences of this extra marker, as well the factors that contribute to their maintenance or elimination through successive cell cycles and phenotypic impact. The study of chromosomal mosaicism provides a natural model to characterize the effect of aneuploidy on genome stability and compare cells with the same genetic background and environment exposure, but differing in the presence of sSMC. Here, we report the functional characterization of different cell lines from two familial patients with mosaic sSMC derived from chromosome 12. We performed studies of proliferation dynamics, stability, and variability of these cells using fluorescent in situ hybridization (FISH), sister chromatid exchanges (SCE), and conventional staining. We also quantified the telomere-related genomic instability of sSMC cells using 3D telomeric profile analysis by quantitative-FISH. sSMC cells exhibited differences in the cell cycle dynamics compared to normal cells. First, the sSMC cells exhibited lower proliferation index and higher frequency of SCE than normal cells, associated with a higher level of chromosomal instability. Second, sSMC cells exhibited more telomeric-related genomic instability. Lastly, the differences of sSMC cells distribution among tissues could explain different phenotypic repercussions observed in patients. These results will help in our understanding of the sSMC stability, maintenance during cell cycle, and the cell cycle variables involved in the different phenotypic manifestations.


Assuntos
Cromossomos Humanos Par 12 , Mosaicismo , Pai , Marcadores Genéticos/genética , Instabilidade Genômica/genética , Humanos , Hibridização in Situ Fluorescente , Masculino , Núcleo Familiar
2.
Braz. j. med. biol. res ; 55: e12072, 2022. tab, graf
Artigo em Inglês | LILACS-Express | LILACS | ID: biblio-1384151

RESUMO

Constitutional genomic imbalances are known to cause malformations, disabilities, neurodevelopmental delay, and dysmorphia and can lead to dysfunctions in the cell cycle. In extremely rare genetic conditions such as small supernumerary marker chromosomes (sSMC), it is important to understand the cellular consequences of this extra marker, as well the factors that contribute to their maintenance or elimination through successive cell cycles and phenotypic impact. The study of chromosomal mosaicism provides a natural model to characterize the effect of aneuploidy on genome stability and compare cells with the same genetic background and environment exposure, but differing in the presence of sSMC. Here, we report the functional characterization of different cell lines from two familial patients with mosaic sSMC derived from chromosome 12. We performed studies of proliferation dynamics, stability, and variability of these cells using fluorescent in situ hybridization (FISH), sister chromatid exchanges (SCE), and conventional staining. We also quantified the telomere-related genomic instability of sSMC cells using 3D telomeric profile analysis by quantitative-FISH. sSMC cells exhibited differences in the cell cycle dynamics compared to normal cells. First, the sSMC cells exhibited lower proliferation index and higher frequency of SCE than normal cells, associated with a higher level of chromosomal instability. Second, sSMC cells exhibited more telomeric-related genomic instability. Lastly, the differences of sSMC cells distribution among tissues could explain different phenotypic repercussions observed in patients. These results will help in our understanding of the sSMC stability, maintenance during cell cycle, and the cell cycle variables involved in the different phenotypic manifestations.

3.
Med Oral Patol Oral Cir Bucal ; 26(4): e451-e458, 2021 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-33247565

RESUMO

BACKGROUND: An increase in oral squamous cell carcinoma (OSCC) cases was observed despite the reduction in exposure to classic risk factors. Although the exact cause of this trend remains unknown, epigenetic factors could be contributing to an increased occurrence of these tumors. This study aims to assess the influence of PMS2 protein immunoexpression on the prognosis of patients with OSCC. MATERIAL AND METHODS: This study comprised 76 cases of OSCC treated between 2011 and 2016. Immunohistochemical staining for PMS2 was performed. For evaluation, 10 fields per histological section were photographed at a 400x magnification and positively-stained cells were counted with Image J. Mann-Whitney and Kruskal-Wallis tests were used to compare the immunolabeling pattern with the clinical-pathological and prognostic characteristics. Survival analysis was performed with Chi-square, Long-Rank Mantel-Cox and Cox regression tests (p<0.05). RESULTS: An overexpression of PMS2 was observed in N0/1 tumors and in oral cancers found in unusual locations. In patients ≤60 years of age, high levels of PMS2 (>60%; p=0.041) were associated with low survival (p=0.029). In multivariate analysis, surgery combined with chemotherapy (p=0.030) and high PMS2 immunoexpression (p=0.042) significantly increased the risk of death for ≤60 years old patients. CONCLUSIONS: The findings of this study indicate that PMS2 can be a potential prognostic protein marker in OSCC patients 60 years of age and younger.


Assuntos
Carcinoma de Células Escamosas , Neoplasias de Cabeça e Pescoço , Neoplasias Bucais , Biomarcadores Tumorais , Carcinoma de Células Escamosas/diagnóstico , Humanos , Imuno-Histoquímica , Pessoa de Meia-Idade , Endonuclease PMS2 de Reparo de Erro de Pareamento , Neoplasias Bucais/diagnóstico , Prognóstico , Carcinoma de Células Escamosas de Cabeça e Pescoço
4.
Braz. j. biol ; 79(2): 243-247, Apr.-June 2019. graf
Artigo em Inglês | LILACS | ID: biblio-989456

RESUMO

Abstract Acupuncture is a therapy of the traditional Chinese medicine technique, which over the years has been widespread in the West. Defined as a needle-point treatment technique (acupoints), exactly preconfigured in the body to produce a specific physiological reaction to restore the balance between the function of conflicting states and homeostasis, alternating states of energy and thus maintain the ideal organ and body organization. Thus, the objective of this study was to map and describe the main points of acupuncture in the species Boa constrictor , and their indications to promote the balance of this species. The unprecedented result of the mapping was the discovery of specific acupoints with individual location indications without distribution in specific meridians and dispersedly distributed in the body.


Resumo A acupuntura é uma técnica terapêutica da Medicina Tradicional Chinesa, que ao longo dos anos tem sido muito difundida no Ocidente. Definida como uma técnica de tratamento com inserção de agulhas em pontos (acupontos) exatamente pré-estabelecidos sobre o organismo, para produzir uma reação fisiológica específica com o intuito de restabelecer o equilíbrio entre estados contraditórios de função e a homeostase, alternando os estados de energia e com isto mantendo a organização do órgão e do organismo. Com isso, o objetivo do presente trabalho foi mapear e descrever os principais pontos de acupuntura nas espécies Boa constrictore suas indicações para promover o equilíbrio dessa espécie. O resultado inédito do mapeamento foi à descoberta de pontos de acupuntura específicos com indicações de localização individuais sem distribuição em meridianos específicos e dispersamente distribuídos no corpo.


Assuntos
Animais , Pontos de Acupuntura , Boidae/anatomia & histologia , Boidae/fisiologia , Medicina Tradicional Chinesa
5.
Braz J Biol ; 79(2): 243-247, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-29995135

RESUMO

Acupuncture is a therapy of the traditional Chinese medicine technique, which over the years has been widespread in the West. Defined as a needle-point treatment technique (acupoints), exactly preconfigured in the body to produce a specific physiological reaction to restore the balance between the function of conflicting states and homeostasis, alternating states of energy and thus maintain the ideal organ and body organization. Thus, the objective of this study was to map and describe the main points of acupuncture in the species Boa constrictor , and their indications to promote the balance of this species. The unprecedented result of the mapping was the discovery of specific acupoints with individual location indications without distribution in specific meridians and dispersedly distributed in the body.


Assuntos
Pontos de Acupuntura , Boidae , Animais , Boidae/anatomia & histologia , Boidae/fisiologia , Medicina Tradicional Chinesa
6.
J Fish Biol ; 91(2): 686-694, 2017 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-28776707

RESUMO

The reproductive biology of Centropomus pectinatus is described from an artisanal fish landings collaborative monitoring programme between May 2012 and April 2013 in estuarine waters in north-eastern Brazil. The total length (LT ) at which 50% are mature was 24 cm, corresponding to 37·7% of the maximum recorded LT . Gonado-somatic indices were variable, but highest values were in June and August 2012. Length-frequency distributions showed male dominance in smaller length classes (15-30 cm) and females in larger length classes (>30 cm).


Assuntos
Perciformes/fisiologia , Reprodução , Animais , Oceano Atlântico , Tamanho Corporal , Brasil , Feminino , Pesqueiros , Masculino , Perciformes/anatomia & histologia , Perciformes/crescimento & desenvolvimento , Estações do Ano , Maturidade Sexual
7.
J Fish Biol ; 90(5): 2111-2124, 2017 May.
Artigo em Inglês | MEDLINE | ID: mdl-28321878

RESUMO

The reproductive biology of the white grunt Haemulon plumierii was studied from 360 individuals obtained from artisanal fisheries landings in the Abrolhos Bank, Brazil, between August 2010 and March 2012. The overall sex-ratio did not differ significantly from 1:1, although males predominated in larger size classes. ß-Binomial modelling of historical sex-ratio data indicated that the catch rate of females has increased in recent years. Females reached maturity at a smaller total length (LT ; 214 mm) than males (235 mm LT ) and the LT at which 50% of all individuals are mature (L50 ) was 220 mm, corresponding to 41·5% of the maximum recorded LT . Variation in the gonado-somatic index and in the relative frequency of reproductive stages indicates that reproduction occurs year round, with increased activity during the austral spring and summer. Fecundity was not size dependent. The reproductive parameters provided here can support management measures focussed on seasonal closures during spawning peaks (September to November and February to March) and minimum sizes (>L50 ) for the capture of this important artisanal fisheries resource in Abrolhos, the region with the largest and most biodiverse coralline reefs in the South Atlantic Ocean.


Assuntos
Pesqueiros , Peixes/fisiologia , Reprodução/fisiologia , Distribuição Animal , Animais , Oceano Atlântico , Feminino , Peixes/classificação , Masculino , Modelos Estatísticos , Dinâmica Populacional , Estações do Ano , Razão de Masculinidade
9.
Braz. j. biol ; 76(3): 743-749, tab, graf
Artigo em Inglês | LILACS | ID: lil-785025

RESUMO

Abstract Many aspects of sex change in reef fishes have been studied, including behavior and social organization. However, gonad histology remains the most robust way to identify sexual patterns in fishes. Some uncommon tissues remain poorly described, such as the accessory gonadal structures found in species from the Gobiidae family, which are rare in other bony fishes. This is the first report of the testicular gland in Gramma brasiliensis and for the Grammatidae family. Between April 2011 and February 2012 eighty specimens were collected during four dive campaigns on the Taipus de Fora reef (13°56’20”S 38°55’32”W), Bahia, Northeast Brazil, and their sex was determined. Thirteen per cent of the active-females and 90% of the active-males had testicular gland tissue in their ovotestis. This discovery led to additional research into the characteristics of the gland tissue and its relationship with gonadal maturation. Three patterns of testicular gland development were found in Brazilian basslet ovotestis. Both ova and sperm-producing gonad contained testicular gland tissue, and the appearance of this tissue seems to be the first modification of ovotestis tissue marking the beginning of the protogynous sex-change process in G. brasiliensis.


Resumo Diversos aspectos da troca de sexo em peixes recifais vem sendo estudados, incluindo comportamentos e organização social. Entretanto, a histologia das gônadas continua sendo a maneira mais robusta para se identificar padrões sexuais em peixes. Alguns tecidos incomuns, tais como as estruturas anexas a gônada encontradas em espécies da família Gobiidae e raras em outras espécies são pouco estudados. Este trabalho é a primeira descrição da glândula testicular em Gramma brasiliensis e para a família Grammatidae. Entre abril de 2011 e fevereiro de 2012, oitenta espécimes foram coletados durante quatro amostragens no recife de Taipus de Fora (13°56’20”S 38°55’32”W), Bahia, Brasil, e tiveram seus sexos determinados. Treze por cento das fêmeas ativas e noventa por cento dos machos ativos apresentaram tecido da glândula testicular em suas gônadas. Esta descoberta levou ao estudo da características dessa estrutura e sua relação com a maturação gonadal. Foram identificados três padrões de desenvolvimento da glândula testicular nas gônadas do Gramma brasiliensis. Tanto as gônadas produtoras de espermatozoides quanto as de oócitos apresentaram tecido da glândula testicular, e o surgimento desse tecido parece ser a primeira modificação gonadal do início da troca de sexo protogínica em G. brasiliensis.


Assuntos
Animais , Masculino , Feminino , Testículo/fisiologia , Perciformes/fisiologia , Adaptação Fisiológica/fisiologia , Organismos Hermafroditas/fisiologia , Brasil , Gônadas/fisiologia
10.
J Thromb Haemost ; 14(10): 2011-2022, 2016 10.
Artigo em Inglês | MEDLINE | ID: mdl-27514025

RESUMO

Essentials Recently, ADAMTS-13 has been shown to undergo substrate induced conformation activation. Conformational quiescence of ADAMTS-13 may serve to prevent off-target proteolysis in plasma. Conformationally active ADAMTS-13 variants are capable of proteolysing the Aα chain of fibrinogen. This should be considered as ADAMTS-13 variants are developed as potential therapeutic agents. Click to hear Dr Zheng's presentation on structure function and cofactor-dependent regulation of ADAMTS-13 SUMMARY: Background Recent work has revealed that ADAMTS-13 circulates in a 'closed' conformation, only fully interacting with von Willebrand factor (VWF) following a conformational change. We hypothesized that this conformational quiescence also maintains the substrate specificity of ADAMTS-13 and that the 'open' conformation of the protease might facilitate proteolytic promiscuity. Objectives To identify a novel substrate for a constitutively active gain of function (GoF) ADAMTS-13 variant (R568K/F592Y/R660K/Y661F/Y665F). Methods Fibrinogen proteolysis was characterized using SDS PAGE and liquid chromatography-tandem mass spectrometry (LC-MS/MS). Fibrin formation was monitored by turbidity measurements and fibrin structure visualized by confocal microscopy. Results ADAMTS-13 exhibits proteolytic activity against the Aα chain of human fibrinogen, but this is only manifest on its conformational activation. Accordingly, the GoF ADAMTS-13 variant and truncated variants such as MDTCS exhibit this activity. The cleavage site has been determined by LC-MS/MS to be Aα chain Lys225-Met226. Proteolysis of fibrinogen by GoF ADAMTS-13 impairs fibrin formation in plasma-based assays, alters clot structure and increases clot permeability. Although GoF ADAMTS-13 does not appear to proteolyse preformed cross-linked fibrin, its proteolytic activity against fibrinogen increases the susceptibility of fibrin to tissue-type plasminogen activator (t-PA)-induced lysis by plasmin and increases the fibrin clearance rate more than 8-fold compared with wild-type (WT) ADAMTS-13 (EC50 values of 3.0 ± 1.7 nm and 25.2 ± 9.7 nm, respectively) in in vitro thrombosis models. Conclusion The 'closed' conformation of ADAMTS-13 restricts its specificity and protects against fibrinogenolysis. Induced substrate promiscuity will be important as ADAMTS-13 variants are developed as potential therapeutic agents against thrombotic thrombocytopenic purpura (TTP) and other cardiovascular diseases.


Assuntos
Proteína ADAMTS13/química , Fibrinogênio/química , Proteína ADAMTS13/genética , Coagulação Sanguínea , Fibrina/química , Fibrinolisina/metabolismo , Células HEK293 , Humanos , Microscopia Confocal , Conformação Proteica , Proteólise , Púrpura Trombocitopênica Trombótica/sangue , Espectrometria de Massas por Ionização e Dessorção a Laser Assistida por Matriz , Especificidade por Substrato , Espectrometria de Massas em Tandem , Trombose
11.
J Fish Biol ; 89(1): 876-89, 2016 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-27264779

RESUMO

In this study, seasonal numerical abundance of the critically endangered Atlantic goliath grouper Epinephelus itajara was estimated by conducting scuba dive surveys and calculating sightings-per-unit-effort (SPUE) at three sites in southern Brazil. Seasonal differences in size and reproductive condition of captured or confiscated specimens were compared. The SPUE differed significantly with season, increasing in late spring and peaking during the austral summer months. A significant effect was observed in the number of fish relative to the lunar cycle. All females sampled during the summer were spawning capable, while all those sampled during other seasons were either regressing or regenerating. What these data strongly infer is that the E. itajara spawning aggregation sites have been located in the southern state of Paraná and the northern state of Santa Catarina and summer is the most likely spawning season. Size frequency distributions, abundance and reproductive state were estimated and correlated with environmental variables.


Assuntos
Bass/fisiologia , Reprodução , Comportamento Social , Animais , Bass/anatomia & histologia , Brasil , Feminino , Masculino , Lua , Ovário/anatomia & histologia , Estações do Ano
12.
Braz J Biol ; 76(3): 743-9, 2016 Apr 19.
Artigo em Inglês | MEDLINE | ID: mdl-27097082

RESUMO

Many aspects of sex change in reef fishes have been studied, including behavior and social organization. However, gonad histology remains the most robust way to identify sexual patterns in fishes. Some uncommon tissues remain poorly described, such as the accessory gonadal structures found in species from the Gobiidae family, which are rare in other bony fishes. This is the first report of the testicular gland in Gramma brasiliensis and for the Grammatidae family. Between April 2011 and February 2012 eighty specimens were collected during four dive campaigns on the Taipus de Fora reef (13°56'20"S 38°55'32"W), Bahia, Northeast Brazil, and their sex was determined. Thirteen per cent of the active-females and 90% of the active-males had testicular gland tissue in their ovotestis. This discovery led to additional research into the characteristics of the gland tissue and its relationship with gonadal maturation. Three patterns of testicular gland development were found in Brazilian basslet ovotestis. Both ova and sperm-producing gonad contained testicular gland tissue, and the appearance of this tissue seems to be the first modification of ovotestis tissue marking the beginning of the protogynous sex-change process in G. brasiliensis.


Assuntos
Adaptação Fisiológica/fisiologia , Organismos Hermafroditas/fisiologia , Perciformes/fisiologia , Testículo/fisiologia , Animais , Brasil , Feminino , Gônadas/fisiologia , Masculino
13.
Cell Mol Life Sci ; 66(2): 254-62, 2009 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-18810320

RESUMO

The peroxisomal protein import machinery displays remarkable properties. Be it its capacity to accept already folded proteins as substrates, its complex architecture or its energetics, almost every aspect of this machinery seems unique. The list of unusual properties is still growing as shown by the recent finding that one of its central components, Pex5p, is transiently monoubiquitinated at a cysteine residue. However, the data gathered in recent years also suggest that the peroxisomal import machinery is not that exclusive and similarities with p97/Cdc48-mediated processes and with multisubunit RING-E3 ligases are starting to emerge. Here, we discuss these data trying to distill the principles by which this complex machinery operates.


Assuntos
Proteínas de Membrana Transportadoras/metabolismo , Peroxissomos/metabolismo , Transporte Proteico/fisiologia , Ubiquitinação , Animais , Humanos , Modelos Moleculares
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