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1.
Brain Inj ; 36(12-14): 1340-1348, 2022 12 06.
Artigo em Inglês | MEDLINE | ID: mdl-36317233

RESUMO

OBJECTIVE: Cognitive recovery after a traumatic brain injury (TBI) may be negatively affected by a prior alcohol use disorder (AUD). This study aims to compare the cognitive recovery of patients who had comorbid TBI and AUD relative to TBI alone and investigate the influence of blood alcohol level (BAL) at hospital admission on this recovery. METHOD: The sample consisted of 42 patients who had sustained a TBI (mild or moderate) and had an AUD diagnosis (TBI+AUD), and 42 patients who had sustained a TBI alone (TBI). The Brief Cognitive Exam in Traumatology (EXACT), designed to evaluate cognitive functions in the acute phase of TBI was administered (± 2 weeks post-injury). RESULTS: After controlling for BAL at admission, the TBI+AUD group had a lower EXACT total score compared to the TBI group. The negative influence of age on the results was more pronounced in the TBI+AUD group. The number of intoxicated patients at admission was also higher in this group, although there was no correlation between BAL at admission and cognitive outcome. CONCLUSION: The presence of an AUD diagnosis seems to exert a greater negative influence on cognitive recovery following a mild/moderate TBI than BAL at admission, especially in older patients.


Assuntos
Alcoolismo , Concussão Encefálica , Lesões Encefálicas Traumáticas , Lesões Encefálicas , Humanos , Idoso , Alcoolismo/complicações , Lesões Encefálicas/psicologia , Lesões Encefálicas Traumáticas/complicações , Consumo de Bebidas Alcoólicas , Cognição
2.
Appl Neuropsychol Adult ; : 1-11, 2022 May 25.
Artigo em Inglês | MEDLINE | ID: mdl-35611614

RESUMO

Although several studies have documented the chronic phase of traumatic brain injury (TBI), few verified the nature and severity of cognitive impairments during the acute phase. Among the studies carried out during the acute phase, instrumental functions were rarely examined compared to attention, memory, and executive functions. This study aimed to compare the nature and intensity of cognitive problems in the acute phase according to TBI severity and age. It was hypothesized that cognitive impairments would increase in line with TBI severity and age, and that instrumental functions would be less affected in victims of mild or moderate TBI than in those with severe TBI. The Brief Cognitive Exam in Traumatology (EXACT), a new and reliable test specifically designed and validated to briefly assess global cognitive functioning during the acute phase, was administered to 319 mild to severe TBI victims (aged 16 to 96 years), within three months post-accident. The EXACT evaluates five domains: Language, Instrumental functions (other than language), Attention and working memory, Episodic memory, and Executive functions and behavioral regulation. Results confirmed the negative influence of TBI severity and age on global cognitive functioning. Also, compared to victims with a mild or moderate TBI, a higher proportion of those with a severe TBI presented impaired instrumental functions (calculation, praxis, and gnosis). Thus, during the acute phase, the nature and severity of cognitive impairments vary according to TBI severity.

3.
Arch Phys Med Rehabil ; 103(11): 2131-2137, 2022 11.
Artigo em Inglês | MEDLINE | ID: mdl-35307342

RESUMO

OBJECTIVE: To determine how results on the EXAmen Cognitif abrégé en Traumatologie (EXACT), a new test specifically designed to briefly assess global cognitive functioning during the acute phase of traumatic brain injury (TBI), can predict long-term functional outcome compared with length of posttraumatic amnesia (PTA), a well-established predictor. DESIGN: Inception cohort. SETTINGS: Level 1 trauma center. PARTICIPANTS: A total of 90 patients (N=90) hospitalized for a moderate or severe TBI. INTERVENTIONS: Not applicable. MAIN OUTCOME MEASURES: Performance on the EXACT in the first 3 months after injury and results on the Disability Rating Scale (DRS) at follow-up 1-2 years later. RESULTS: EXACT scores were all correlated with length of PTA and DRS result. Compared with length of PTA, the EXACT added significantly to the regression and improved prediction of functional outcome. More specifically, a total score ≤80 on the EXACT was associated with a higher rate of long-term disability because of more severe TBI consequences. Behavioral regulation and executive functions were the cognitive domains that showed the most impairment, followed by attention and working memory as well as episodic memory. Except for length of PTA and hospital stay, the DRS score was not correlated with other demographic (age, education) or clinical variables (Glasgow Coma Scale and maximum score on the Therapy Intensity Level Scale). CONCLUSIONS: The EXACT can be administered to most patients early in the acute phase of TBI, and results could be used, along with other predictors such as PTA, to estimate their long-term functional sequelae. The EXACT may be a promising brief cognitive instrument for future studies investigating recovery after TBI.


Assuntos
Lesões Encefálicas Traumáticas , Lesões Encefálicas , Humanos , Lesões Encefálicas/psicologia , Lesões Encefálicas Traumáticas/psicologia , Escala de Coma de Glasgow , Testes Neuropsicológicos , Função Executiva , Recuperação de Função Fisiológica
4.
Int J Circumpolar Health ; 80(1): 1880143, 2021 12.
Artigo em Inglês | MEDLINE | ID: mdl-33691591

RESUMO

This study reports results of a life course study conducted with Inuit in Nunavik to obtain information on the life adversities and cumulative burden of adversity for three groups: those who died by suicide, those who attempted suicide, and those who experienced suicidal ideation but never attempted. The study involved different levels of collaboration between health authorities, front-line health workers and the research team. Results indicate that substance misuse and relational difficulties are most associated with the burden of adversity for those people who died by suicide, while bullying is most associated with the burden of adversity for those people who have made suicide attempts and those who have never made a suicide attempt. Specifically targeting parent-child relations, substance misuse, and bullying may be an important upstream strategy for reducing future suicidality in Nunavik.


Assuntos
Bullying , Tentativa de Suicídio , Humanos , Relações Pais-Filho , Fatores de Risco , Ideação Suicida
5.
Clin Neuropsychol ; 33(7): 1175-1194, 2019 10.
Artigo em Inglês | MEDLINE | ID: mdl-31007154

RESUMO

Objective: Prospective memory (PM) is the ability to remember to perform an intention at the appropriate time in the future. It is of primary importance for daily living, and its disruption may impact functional autonomy. To date, few studies have examined PM during the acute phase of mild traumatic brain injury (mTBI), despite the high prevalence of this neurological condition and its potential impact on cognition. Method: Twenty mTBI patients (time since injury ranged from 45 to 73 days) and 15 healthy control participants performed the Ecological Test of Prospective Memory (TEMP), a simulated errand task in which participants were required to execute 10 event-based (EB) and five time-based (TB) tasks. The TEMP separately evaluates PM phases as well as prospective and retrospective components in event- and time-based conditions. Participants also completed a neuropsychological test battery. Correlations were performed between cognitive composite scores and the TEMP. Results: mTBI patients experienced difficulty in learning the content of intentions, retrieving these intentions in the time-based condition (prospective component) and recalling the associated actions in the event- and time-based conditions (retrospective component). Retrospective memory composite score was correlated with the learning and retention phases of the TEMP, whereas attention/working memory and executive composite scores were correlated with the time-based condition and performance on the ongoing task. Conclusion: These results suggest the presence of global PM impairment during the acute phase of mTBI, as well as impairment of retrospective memory, attention/working memory, and executive functions, which are key components for PM performance.


Assuntos
Lesões Encefálicas Traumáticas/diagnóstico , Memória Episódica , Testes Neuropsicológicos/normas , Doença Aguda , Adulto , Feminino , Voluntários Saudáveis , Humanos , Masculino , Pessoa de Meia-Idade , Estudos Prospectivos , Medição de Risco , Adulto Jovem
6.
Hum Reprod ; 32(6): 1293-1303, 2017 06 01.
Artigo em Inglês | MEDLINE | ID: mdl-28449121

RESUMO

STUDY QUESTION: What are the chromosome segregation errors in human oocyte meiosis-I that may underlie oocyte aneuploidy? SUMMARY ANSWER: Multiple modes of chromosome segregation error were observed, including tri-directional anaphases, which we attribute to loss of bipolar spindle structure at anaphase-I. WHAT IS KNOWN ALREADY: Oocyte aneuploidy is common and associated with infertility, but mechanistic information on the chromosome segregation errors underlying these defects is scarce. Lagging chromosomes were recently reported as a possible mechanism by which segregation errors occur. STUDY DESIGN, SIZE, DURATION: Long-term confocal imaging of chromosome dynamics in 50 human oocytes collected between January 2015 and May 2016. PARTICIPANTS/MATERIALS, SETTING, METHODS: Germinal vesicle (GV) stage oocytes were collected from women undergoing intracytoplasmic sperm injection cycles and also CD1 mice. Oocytes were microinjected with complementary RNAs to label chromosomes, and in a subset of oocytes, the meiotic spindle. Oocytes were imaged live through meiosis-I using confocal microscopy. 3D image reconstruction was used to classify chromosome segregation phenotypes at anaphase-I. Segregation phenotypes were related to spindle dynamics and cell cycle timings. MAIN RESULTS AND THE ROLE OF CHANCE: Most (87%) mouse oocytes segregated chromosomes with no obvious defects. We found that 20% of human oocytes segregated chromosomes bi-directionally with no lagging chromosomes. The rest were categorised as bi-directional anaphase with lagging chromosomes (20%), bi-directional anaphase with chromatin mass separation (34%) or tri-directional anaphase (26%). Segregation errors correlated with chromosome misalignment prior to anaphase. Spindles were tripolar when tri-directional anaphases occurred. Anaphase phenotypes did not correlate with meiosis-I duration (P = 0.73). LARGE SCALE DATA: Not applicable. LIMITATIONS, REASONS FOR CAUTION: Oocytes were recovered at GV stage after gonadotrophin-stimulation, and the usual oocyte quality caveats apply. Whilst the possibility that imaging may affect oocyte physiology cannot be formally excluded, detailed controls and justifications are presented. WIDER IMPLICATIONS OF THE FINDINGS: This is one of the first reports of live imaging of chromosome dynamics in human oocytes, introducing tri-directional anaphases as a novel potential mechanism for oocyte aneuploidy. STUDY FUNDING/COMPETING INTEREST(S): This study was funded by grants from Fondation Jean-Louis Lévesque (Canada), CIHR (MOP142334) and CFI (32711) to GF. JH is supported by Postdoctoral Fellowships from The Lalor Foundation and CIHR (146703). The authors have no conflict of interest.


Assuntos
Anáfase , Aneuploidia , Segregação de Cromossomos , Oócitos/patologia , Oogênese , Animais , Animais não Endogâmicos , Células Cultivadas , Feminino , Humanos , Imageamento Tridimensional , Infertilidade Feminina/patologia , Proteínas Luminescentes/genética , Proteínas Luminescentes/metabolismo , Camundongos , Microinjeções , Microscopia Confocal , Microscopia de Fluorescência , Oócitos/citologia , Oócitos/metabolismo , Interferência de RNA , RNA Complementar/metabolismo , Proteínas Recombinantes de Fusão/metabolismo , Organismos Livres de Patógenos Específicos , Fuso Acromático/metabolismo , Fuso Acromático/patologia , Imagem com Lapso de Tempo
7.
Curr Biol ; 20(22): 2046-51, 2010 Nov 23.
Artigo em Inglês | MEDLINE | ID: mdl-21055941

RESUMO

Polar body extrusion (PBE) is the specialized asymmetric division by which oocytes accomplish reduction in ploidy and retention of cytoplasm. During maternal gametogenesis, as in male meiosis and mitosis, cytokinesis is accomplished by a ring rich in active Rho, myosin, and formin-nucleated F-actin [1-7]. However, unlike mitosis, wherein the contractile ring encircles the cell equator, the polar body ring assembles as a discoid cortical washer. Here we show that in Caenorhabditis elegans, the meiotic contractile ring transforms during closure from a disc above the spindle to a cylinder around the spindle midzone. The meiotic midbody tube comprises stacked cytoskeletal rings. This topological transition suggests a novel mechanism for constriction of an initially discoid cytokinetic ring. Analysis of mouse PBE indicates that midbody tube formation is a conserved process. Depletion of the scaffold protein anillin (ANI-1) from C. elegans results in large and unstable polar bodies that often fuse with the oocyte. Anillin is dispensable for contractile ring assembly, initiation, and closure but is required for the meiotic contractile ring to transform from a disc into a tube. We propose that cytoskeletal bundling by anillin promotes formation of the midbody tube, which ensures the fidelity of PBE.


Assuntos
Actomiosina/metabolismo , Proteínas de Caenorhabditis elegans/fisiologia , Caenorhabditis elegans/ultraestrutura , Citocinese/fisiologia , Proteínas dos Microfilamentos/fisiologia , Animais , Caenorhabditis elegans/genética , Caenorhabditis elegans/metabolismo , Proteínas de Caenorhabditis elegans/genética , Proteínas de Caenorhabditis elegans/metabolismo , Polaridade Celular , Meiose/fisiologia , Proteínas dos Microfilamentos/genética , Proteínas dos Microfilamentos/metabolismo , Modelos Biológicos
8.
J Cardiovasc Nurs ; 25(2): 130-41, 2010.
Artigo em Inglês | MEDLINE | ID: mdl-20168193

RESUMO

BACKGROUND AND RESEARCH OBJECTIVE: : Heart failure (HF) patients experience frequent episodes of decompensation. While medication and behavior change play a major role in maintaining physiological stability, patient adherence to self-care recommendations is not optimal. The Theory of Heart Failure Self-care helped to understand the concepts of self-care and chose a model of intervention. Conviction and confidence are central factors in facilitating self-care. Motivational interviewing (MI), which aims to strengthen conviction and confidence, has been shown to improve self-care. In addition, the Transtheoretical Model, based on patients' readiness to change, also has proven efficacy. The MI based on the stages of change (MISC), a combination of MI and Transtheoretical Model, offers promise for improving self-care. The goal of this pilot study was to evaluate the preliminary effect of an MISC intervention on HF patients' self-care behaviors. SUBJECTS AND METHOD: : Thirty patients were recruited from an HF clinic and randomly assigned to an experimental (EG) or control group (n = 15/group). Patients from the EG received 3 interventions (1 in person, 2 on the phone). Data were collected at baseline and at 1 month after randomization. The effect of the intervention was assessed on 5 self-care outcomes using analysis-of-covariance models. RESULTS AND CONCLUSION: : Significant results were obtained regarding the confidence in performing self-care behaviors specific to HF (P =.005). Although the results of the other hypotheses were not statistically significant, for the majority, trends were in the expected direction in favor of the EG. The study suggests that an MISC intervention is useful to increase patients' confidence in HF self-care and has potential to improve self-care. Further research is needed.


Assuntos
Terapia Comportamental , Insuficiência Cardíaca/enfermagem , Insuficiência Cardíaca/psicologia , Motivação , Padrões de Prática em Enfermagem , Autocuidado/psicologia , Idoso , Idoso de 80 Anos ou mais , Feminino , Insuficiência Cardíaca/terapia , Humanos , Masculino , Pessoa de Meia-Idade , Cuidados de Enfermagem , Cooperação do Paciente , Projetos Piloto , Autoeficácia
9.
PLoS One ; 4(10): e7500, 2009 Oct 19.
Artigo em Inglês | MEDLINE | ID: mdl-19838297

RESUMO

The cystatin protein superfamily is characterized by the presence of conserved sequences that display cysteine protease inhibitory activity (e.g., towards cathepsins). Type 1 and 2 cystatins are encoded by 25 genes of which 23 are grouped in 2 clusters localized on mouse chromosomes 16 and 2. The expression and essential roles of most of these genes in mouse development and hematopoiesis remain poorly characterized. In this study, we describe a set of quantitative real-time PCR assays and a global expression profile of cystatin genes in normal mouse tissues. Benefiting from our collection of DelES embryonic stem cell clones harboring large chromosomal deletions (to be reported elsewhere), we selected a clone in which a 95-kb region of chromosome 16 is missing (Del(16qB3Delta/+)). In this particular clone, 2 cystatin genes, namely Csta and Stfa2l1 are absent along with 2 other genes (Fam162a, Ccdc58) and associated intergenic regions. From this line, we established a new homozygous mutant mouse model (Del(16qB3Delta/16qB3Delta)) to assess the in vivo biological functions of the 2 deleted cystatins. Stfa2l1 gene expression is high in wild-type fetal liver, bone marrow, and spleen, while Csta is ubiquitously expressed. Homozygous Del(16qB3Delta/16qB3Delta) animals are phenotypically normal, fertile, and not overtly susceptible to spontaneous or irradiation-induced tumor formation. The hematopoietic stem and progenitor cell activity in these mutant mice are also normal. Interestingly, quantitative real-time PCR expression profiling reveals a marked increase in the expression levels of Stfa2l1/Csta phylogenetically-related genes (Stfa1, Stfa2, and Stfa3) in Del(16qB3Delta/16qB3Delta) hematopoietic tissues, suggesting that these candidate genes might be contributing to compensatory mechanisms. Overall, this study presents an optimized approach to globally monitor cystatin gene expression as well as a new mouse model deficient in Stfa2l1/Csta genes, expanding the available tools to dissect cystatin roles under normal and pathological conditions.


Assuntos
Deleção Cromossômica , Cistatina A/genética , Cistatinas/biossíntese , Perfilação da Expressão Gênica , Regulação da Expressão Gênica , Células-Tronco/citologia , Alelos , Animais , Sobrevivência Celular , Modelos Animais de Doenças , Feminino , Células-Tronco Hematopoéticas/citologia , Homozigoto , Camundongos , Camundongos Endogâmicos C57BL
10.
J Biol Chem ; 283(49): 34045-52, 2008 Dec 05.
Artigo em Inglês | MEDLINE | ID: mdl-18809675

RESUMO

Entry inhibitors of human immunodeficiency virus, type 1 (HIV-1) have been the focus of much recent research. C34, a potent fusion inhibitor derived from the HR2 region of gp41, was engineered into a 1:1 human serum albumin conjugate through stable covalent attachment of a maleimido-C34 analog onto cysteine 34 of albumin. This bioconjugate, PC-1505, was designed to require less frequent dosing and less peptide than T-20 and was assessed for its antifusogenic activity both in vitro and in vivo in the SCID-hu Thy/Liv mouse model. PC-1505 was essentially equipotent to the original C34 peptide and to T-20 in vitro. In HIV-1-infected SCID-hu Thy/Liv mice, T-20 lost activity with infrequent dosing, whereas the antiviral potency of PC-1505 was sustained, and PC-1505 was active against T-20-resistant ("DIV") virus with a G36D substitution in gp41. The in vivo results are the direct result of a significantly improved pharmacokinetic profile for the C34 peptide following albumin conjugation. Contrary to previous reports that the gp41 NHR trimer is poorly accessible to C34 fused to protein cargoes of increasing size (Hamburger, A. E., Kim, S., Welch, B. D., and Kay, M. S. (2005) J. Biol. Chem. 280, 12567-12572), these results are the first demonstration of the capacity for a large, endogenous serum protein to gain unobstructed access to the transient gp41 intermediates that exist during the HIV fusion process, and it supports further development of albumin conjugation as a promising approach to inhibit HIV-1 entry.


Assuntos
Albuminas/química , Proteína gp41 do Envelope de HIV/química , Proteína gp41 do Envelope de HIV/farmacologia , Inibidores da Fusão de HIV/farmacologia , HIV-1/metabolismo , Fragmentos de Peptídeos/química , Fragmentos de Peptídeos/farmacologia , Peptídeos/farmacologia , Proteínas Virais de Fusão/química , Sequência de Aminoácidos , Animais , Modelos Animais de Doenças , Enfuvirtida , Inibidores da Fusão de HIV/química , Camundongos , Camundongos SCID , Dados de Sequência Molecular , Peptídeos/química , Ratos , Ratos Sprague-Dawley
11.
Vision Res ; 46(10): 1646-54, 2006 May.
Artigo em Inglês | MEDLINE | ID: mdl-16375945

RESUMO

Attention to a visual target can affect perception of a subsequent target for half a second, increasing its sensitivity to backward masking (the attentional blink, AB). In 6 studies, we compared the AB when the second target and its mask had a common onset and when the mask appeared after the target. The results indicate that common-onset masks do not produce large ABs even when there is a feature change or an interruption of the mask after the target but do produce a large AB if the location of the mask is changed. The data suggest that new object onsets reduce conscious access to unattended targets.


Assuntos
Atenção , Percepção de Forma , Mascaramento Perceptivo , Adulto , Sensibilidades de Contraste , Feminino , Área de Dependência-Independência , Humanos , Masculino , Estimulação Luminosa/métodos , Fatores de Tempo
12.
Bioconjug Chem ; 16(4): 1000-8, 2005.
Artigo em Inglês | MEDLINE | ID: mdl-16029043

RESUMO

A series of human insulin maleimido derivatives with short and long linkers was synthesized by exploiting the variations in the pK(a) values and environment of the three amino groups present in the protein. The syntheses were accomplished in organic solvent because of maleimide's instability in basic aqueous media. The derivatives thus obtained were conjugated to the free thiol on Cys34 of human serum albumin (HSA) and purified. A structure-activity relationship based on in vitro receptor binding and activation results for this series of insulin-HSA conjugates showed that the best compounds were attached at the B1 position of insulin with either short or long linkers. Two conjugates were administered subcutaneously to streptozotocin-induced diabetic rats and found to possess blood glucose normalizing activity up to 8 h post-administration. The return to diabetic plasma glucose levels was not observed within the time frame of the experiment (48 h). In comparison, the insulin-treated group's normalization activity lasted 2 h and returned to a diabetic level at 8 h. The onset of the conjugate activities were delayed by 1 h when compared to the activity of human insulin. The study results led to the identification of CJC-1575 as a potent and long lasting human insulin analogue.


Assuntos
Insulina/química , Albumina Sérica/química , Sequência de Aminoácidos , Animais , Diabetes Mellitus Experimental/terapia , Avaliação Pré-Clínica de Medicamentos , Eletroforese em Gel de Poliacrilamida , Humanos , Insulina/administração & dosagem , Insulina/síntese química , Insulina/farmacocinética , Espectroscopia de Ressonância Magnética , Masculino , Dados de Sequência Molecular , Ratos , Ratos Sprague-Dawley , Proteínas Recombinantes de Fusão/administração & dosagem , Proteínas Recombinantes de Fusão/síntese química , Proteínas Recombinantes de Fusão/química , Proteínas Recombinantes de Fusão/farmacocinética , Albumina Sérica/administração & dosagem , Albumina Sérica/síntese química , Albumina Sérica/farmacocinética , Estreptozocina , Relação Estrutura-Atividade
13.
Endocrinology ; 146(7): 3052-8, 2005 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-15817669

RESUMO

In vivo bioconjugation to the free thiol on Cys34 of serum albumin by a strategically placed reactive group on a bioactive peptide is a useful tool to extend plasma half-life. Three maleimido derivates of human GH-releasing factor (hGRF)(1-29) were synthesized and bioconjugated to human serum albumin ex vivo. All three human serum albumin conjugates showed enhanced in vitro stability against dipeptidylpeptidase-IV and were bioactive in a GH secretion assay in cultured rat anterior pituitary cells. When the maleimido derivatives were individually administered sc to normal male Sprague Dawley rats, an acute secretion of GH was measured in plasma. The best compound, CJC-1295, showed a 4-fold increase in GH area under the curve over a 2-h period compared with hGRF(1-29). CJC-1295, a tetrasubstituted form of hGRF(1-29) with an added N epsilon-3-maleimidopropionamide derivative of lysine at the C terminus, was selected for further pharmacokinetic evaluation, where it was found to be present in plasma beyond 72 h. A Western blot analysis of the plasma of a rat injected with CJC-1295 showed the presence of a CJC-1295 immunoreactive species on the band corresponding to serum albumin, appearing after 15 min and remaining in circulation beyond 24 h. These results led to the identification of CJC-1295 as a stable and active hGRF(1-29) analog with an extended plasma half-life.


Assuntos
Proteínas de Ligação a DNA/metabolismo , Hormônio Liberador de Hormônio do Crescimento/análogos & derivados , Hormônio Liberador de Hormônio do Crescimento/farmacologia , Fragmentos de Peptídeos/farmacologia , Adeno-Hipófise/metabolismo , Albumina Sérica/farmacologia , Fatores de Transcrição/metabolismo , Sequência de Aminoácidos , Animais , Células Cultivadas , Proteínas de Ligação a DNA/efeitos dos fármacos , Dipeptidil Peptidase 4/farmacologia , Estabilidade de Medicamentos , Hormônio Liberador de Hormônio do Crescimento/administração & dosagem , Hormônio Liberador de Hormônio do Crescimento/genética , Hormônio Liberador de Hormônio do Crescimento/metabolismo , Hormônio Liberador de Hormônio do Crescimento/farmacocinética , Meia-Vida , Humanos , Injeções Subcutâneas , Masculino , Dados de Sequência Molecular , Fragmentos de Peptídeos/administração & dosagem , Fragmentos de Peptídeos/genética , Fragmentos de Peptídeos/metabolismo , Fragmentos de Peptídeos/farmacocinética , Ratos , Ratos Sprague-Dawley , Sermorelina/farmacocinética , Albumina Sérica/metabolismo , Fatores de Transcrição/efeitos dos fármacos
14.
Biol Reprod ; 68(4): 1098-106, 2003 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-12606467

RESUMO

To study the process of mammalian sex determination and in particular to further understand the mechanisms of transcriptional regulation of the SRY gene, we have isolated a 4.5-kilobase (kb) pig SRY 5' flanking sequence. To facilitate the in vitro analysis of these sequences, we have generated a porcine genital ridge (PGR) cell line (9E11) that expresses SRY as well as SOX9, steroidogenic factor-1 (SF-1), and DAX1. Via primer extension analysis on RNA from this cell line, a transcription start site for porcine SRY was identified at -661 base pairs (bps) 5' from the translation initiation site. Deletion studies of the SRY 5' flanking sequences in PGR 9E11 cells demonstrated that -1.4 kb of 5' flanking sequences retained full transcriptional activity compared with the -4.5 kb fragment, but that transcriptional activity fell when further deletions were made. Sequences downstream of the transcriptional start site are important for promoter activity, because deleting transcribed but not translated sequences eliminated promoter activity. Sequence analysis of the -1.4 kb fragment identified two potential binding sites for SF-1, at -1369 and at -290 from the ATG. To address the role of SF-1 transactivation in SRY promoter activity, mutagenesis studies of the potential SF-1 binding sites were performed and revealed that these sites were indeed important for SRY promoter activity. Cotransfection studies in a heterologous cell system (mouse CV-1 cells) demonstrated that pig SF-1 was able to transactivate the pig SRY promoter. Gel shift assays confirmed that the upstream site was recognized by mouse SF-1 protein. We conclude that two sites for SF-1 transactivation exist within the pig SRY promoter, at -1369 bp and at -290 bp, and that the site at -1369 bp is quantitatively the most important.


Assuntos
Proteínas de Ligação a DNA/genética , Proteínas de Ligação a DNA/fisiologia , Proteínas Nucleares , Regiões Promotoras Genéticas , Suínos/genética , Fatores de Transcrição/fisiologia , Animais , Sequência de Bases/genética , Sítios de Ligação/genética , Linhagem Celular , Proteínas de Ligação a DNA/metabolismo , Embrião de Mamíferos/citologia , Fatores de Transcrição Fushi Tarazu , Deleção de Genes , Genitália/embriologia , Proteínas de Homeodomínio , Dados de Sequência Molecular , Mutação , Regiões Promotoras Genéticas/genética , Receptores Citoplasmáticos e Nucleares , Proteína da Região Y Determinante do Sexo , Fator Esteroidogênico 1 , Suínos/embriologia , Fatores de Transcrição/metabolismo , Transcrição Gênica/fisiologia
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