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1.
Aging (Albany NY) ; 7(11): 911-27, 2015 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-26546739

RESUMO

The TERT gene encodes for the reverse transcriptase activity of the telomerase complex and mutations in TERT can lead to dysfunctional telomerase activity resulting in diseases such as dyskeratosis congenita (DKC). Here, we describe a novel TERT mutation at position T1129P leading to DKC with progressive bone marrow (BM) failure in homozygous members of a consanguineous family. BM hematopoietic stem cells (HSCs) of an affected family member were 300-fold reduced associated with a significantly impaired colony forming capacity in vitro and impaired repopulation activity in mouse xenografts. Recent data in yeast suggested improved cellular checkpoint controls by mTOR inhibition preventing cells with short telomeres or DNA damage from dividing. To evaluate a potential therapeutic option for the patient, we treated her primary skin fibroblasts and BM HSCs with the mTOR inhibitor rapamycin. This led to prolonged survival and decreased levels of senescence in T1129P mutant fibroblasts. In contrast, the impaired HSC function could not be improved by mTOR inhibition, as colony forming capacity and multilineage engraftment potential in xenotransplanted mice remained severely impaired. Thus, rapamycin treatment did not rescue the compromised stem cell function of TERTT1129P mutant patient HSCs and outlines limitations of a potential DKC therapy based on rapamycin.


Assuntos
Antígenos CD34/análise , Senescência Celular , Disceratose Congênita/genética , Células-Tronco Hematopoéticas/fisiologia , Mutação , Sirolimo/farmacologia , Serina-Treonina Quinases TOR/antagonistas & inibidores , Telomerase/genética , Animais , Feminino , Células HeLa , Transplante de Células-Tronco Hematopoéticas , Humanos , Camundongos , Telômero
2.
PLoS One ; 10(8): e0135997, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-26275228

RESUMO

BACKGROUND: Children and patients with cognitive deficits may find it difficult to understand the implication of research. In the European Union (EU), clinical studies outside the EU directives concerning medicinal products or medical devices, i.e., "miscellaneous clinical studies", have no legally mandated timelines for institutional review boards' (IRB) decisions. GOAL: To evaluate the review process of IRBs for two different "miscellaneous" multicenter clinical research protocols involving vulnerable subjects (children and adult stroke patients). METHODS: Descriptive and comparative statistics. Protocol 1 is a prospective, multicenter, cross-sectional screening study of a symptomatic pediatric population at risk for Fabry disease involving genetic testing (NCT02152189). Protocol 2 is a prospective, multicenter, randomized, controlled, open-label, blinded endpoint post-market study to evaluate the effectiveness of stent retrievers (NCT02135926). After having obtained positive initial IRB votes at the main study site, both protocols were subsequently submitted to the remaining IRBs. RESULTS: Protocol 1 was submitted to 19 IRBs. No IRB objected to the study. Median time-to-final vote was 34 (IQR 10-65; range 0 to 130) days. Two IRBs accepted the coordinating center's IRB votes without re-evaluation. Changes to the informed consent documents were asked by 7/19 IRBs, amendments to the protocol by 2. Protocol 2 was submitted to 16 IRBs. Fifteen decisions were made. No IRB objected to the study. Median time-to final vote was 59 (IQR 10 to 65; range 0 to 128) days, which was not statistically significantly different compared with protocol 1 (Wilcoxon test). Two IRBs accepted a previous IRB decision and did not conduct an independent review. Eight/16 IRBs required changes to the informed consent documents; two IRBs recommended an amendment of the protocol. CONCLUSION: Both clinical research protocols involving vulnerable populations were well accepted. IRB workflows and decision times varied substantially. Some IRBs accepted a previous IRB decision without the necessity of another reevaluation process. Requested changes were focused on the informed consent documents. A more standardized approach across jurisdictions is desirable.


Assuntos
Comitês de Ética em Pesquisa , União Europeia , Doença de Fabry/genética , Stents , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Estudos Transversais , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Estudos Prospectivos
3.
Eur J Pediatr ; 168(8): 969-73, 2009 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-19066960

RESUMO

INTRODUCTION: Multiple sulfatase deficiency is biochemically characterized by the accumulation of sulfated lipids and acid mucopolysaccharides. CASE REPORT: We report clinical, biochemical, and molecular findings in a female newborn affected with a severe form of multiple sulfatase deficiency (Mendelian Inheritance in Man (MIM) # 272200). She presented with primary microcephaly, facial anomalies including depressed nasal bridge, nasal hypoplasia, anteverted nostrils, smooth philtrum, limited mobility of hip and knee joints, mild ichthyosis, as well as muscular hypotonia. The diagnosis is based on detection of excessive mucopolysacchariduria and enzymatic assays performed in leucocytes which showed complete deficiency of all of the measured sulfatases. Sequencing of the coding region of the underlying gene, SUMF1, could not identify any mutation. However, failure to detect the corresponding mRNA by reverse transcription polymerase chain reaction proves defective SUMF1 expression. CONCLUSION: The diagnosis of neonatal MSD should be considered when dealing with the association of distinct facial anomalies, limited joint mobility, ichthyosis, and muscular hypotonia.


Assuntos
Anormalidades Múltiplas , Mucopolissacaridoses , Sulfatases/deficiência , Face/anormalidades , Feminino , Luxação Congênita de Quadril , Humanos , Recém-Nascido , Microcefalia , Mucopolissacaridoses/genética , Oxirredutases atuantes sobre Doadores de Grupo Enxofre , Sulfatases/genética
4.
Neoplasia ; 4(3): 243-54, 2002.
Artigo em Inglês | MEDLINE | ID: mdl-11988844

RESUMO

The distribution of alpha6/alpha3 integrin in adhesion complexes at the basal membrane in human normal and cancer prostate glands was analyzed in 135 biopsies from 61 patients. The levels of the polarized alpha6/alpha3 integrin expression at the basal membrane of prostate tumor glands were determined by quantitative immunohistochemistry. The alpha6/alpha3 integrin expression was compared with Gleason sum score, pathological stage, and preoperative serum prostate-specific antigen (PSA). The associations were assessed by statistical methods. Eighty percent of the tumors expressed the alpha6 or alpha3 integrin and 20% was integrin-negative. Gleason sum score, but not serum PSA, was associated with the integrin expression. Low Gleason sum score correlated with increased integrin expression, high Gleason sum score with low and negative integrin expression. Three prostate tumor phenotypes were distinguished based on differential integrin expression. Type I coexpressed both alpha6 and alpha3 subunits, type II exclusively expressed alpha6 integrin, and type III expressed alpha3 integrin only. Fifteen cases were further examined for the codistribution of vinculin, paxillin, and CD 151 on frozen serial sections using confocal laser scanning microscopy. The alpha6/alpha3 integrins, CD151, paxillin, and vinculin were present within normal glands. In prostate carcinoma, alpha6 integrin was colocalized with CD 151, but not with vinculin or paxillin. In tumor phenotype I, the alpha6 subunit did not colocalize with the alpha subunit indicating the existence of two different adhesion complexes. Human prostate tumors display on their cell surface the alpha6beta1 and/or alpha3beta1 integrins. Three tumor phenotypes associated with two different adhesion complexes were identified, suggesting a reorganization of cell adhesion structures in prostate cancer.


Assuntos
Antígenos CD/biossíntese , Integrinas/biossíntese , Neoplasias da Próstata/metabolismo , Alelos , Sítios de Ligação , Biópsia , Adesão Celular , Proteínas do Citoesqueleto/metabolismo , Humanos , Imuno-Histoquímica , Integrina alfa3 , Integrina alfa6 , Masculino , Microscopia Confocal , Microscopia de Fluorescência , Mutação , Paxilina , Fenótipo , Fosfoproteínas/metabolismo , Antígeno Prostático Específico/biossíntese , Tetraspanina 24 , Vinculina/metabolismo
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