RESUMEN
Oral-facial-digital (OFD) syndromes are a subgroup of ciliopathies distinguished by the co-occurrence of hamartomas and/or multiple frenula of the oral region and digital anomalies. Several clinical forms of OFD syndromes are distinguished by their associated anomalies and/or inheritance patterns, and at least 20 genetic types of OFD syndromes have been delineated. We describe here a child with preaxial and postaxial polydactyly, lingual hamartoma, a congenital heart defect, delayed development and cerebellar peduncles displaying the molar tooth sign. Whole-exome sequencing and SNP array identified compound heterozygous variants in the INTU gene, which encodes a protein involved in the positioning of the ciliary basal body. INTU is a subunit of the CPLANE multiprotein complex essential for the assembly of IFT-A particles and intraflagellar transport. This report of a second patient with INTU-related OFD syndrome and the further delineation of its neuroimaging and skeletal phenotype now allow INTU-related OFD syndromes to be classified within the OFD syndrome type VI group. Patients display a phenotype similar to that of mice with a hypomorphic mutation of Intu, but with the addition of a heart defect.
Asunto(s)
Proteínas del Citoesqueleto/genética , Proteínas de la Membrana/genética , Síndromes Orofaciodigitales/genética , Humanos , Lactante , Recién Nacido , Imagen por Resonancia Magnética , Masculino , Síndromes Orofaciodigitales/diagnóstico por imagenRESUMEN
BACKGROUND: A large number of taxa have undergone evolutionary radiations in mountainous areas, rendering alpine systems particularly suitable to study the extrinsic and intrinsic factors that have shaped diversification patterns in plants. The species-rich genus Saxifraga L. is widely distributed throughout the Northern Hemisphere, with high species numbers in the regions adjacent to the Qinghai-Tibet Plateau (QTP) in particular the Hengduan Mountains and the Himalayas. Using a dataset of 297 taxa (representing at least 60% of extant Saxifraga species), we explored the variation of infrageneric diversification rates. In addition, we used state-dependent speciation and extinction models to test the effects of geographic distribution in the Hengduan Mountains and the entire QTP region as well as of two morphological traits (cushion habit and specialized lime-secreting glands, so-called hydathodes) on the diversification of this genus. RESULTS: We detected two to three rate shifts across the Saxifraga phylogeny and two of these shifts led to radiations within two large subclades of Saxifraga, sect. Ciliatae Haworth subsect. Hirculoideae Engl. & Irmsch. and sect. Porphyrion Tausch subsect. Kabschia Engl. GEOSSE analyses showed that presence in the Hengduan Mountains had a positive effect on diversification across Saxifraga. Influence of these mountains was strongest in Saxifraga sect. Ciliatae subsect. Hirculoideae given its pronounced distribution there, and thus the radiation in this group can be classified at least partially as geographic. In contrast, the evolution of the cushion life form and lime-secreting hydathodes had positive effects on diversification only in selected Saxifraga sections, including sect. Porphyrion subsect. Kabschia. We therefore argue that radiation in this group was likely adaptive. CONCLUSIONS: Our study underlines the complexity of processes and factors underpinning plant radiations: Even in closely related lineages occupying the same life zone, shifts in diversification are not necessarily governed by similar factors. In conclusion, alpine plant radiations result from a complex interaction among geographical settings and/or climatic modifications providing key opportunities for diversification as well as the evolution of key innovations.
Asunto(s)
Saxifragaceae/clasificación , Saxifragaceae/genética , Evolución Biológica , Cambio Climático , Geografía , Filogenia , Saxifragaceae/anatomía & histología , TibetRESUMEN
OBJECTIVES: The heterogeneity of tinnitus in terms of etiology, presentation and sometimes severe impact on quality of life hinders treatment and clinical research. The European School for Interdisciplinary Tinnitus Research Screening Questionnaire (ESIT-SQ) collects standardized tinnitus characteristics for patient subtyping. A validated French translation of the ESIT-SQ is presented here. METHOD: On the initiative of the French Interdisciplinary Tinnitus Association (AFREPA), 3 translators (1 professional translator, 1 clinician and 1 researcher) were missioned to translate the English version of the ESIT-SQ into French, adhering to good practice guidelines. Nine patients were recruited with the help of the France-Acouphènes patient association, to test and validate the translation. Lastly, an exploratory survey of responses to the French questionnaire was conducted online via the Siopi mobile phone application. RESULTS: The French translation of the ESIT-SQ was successfully validated. 105 patients responded to the exploratory survey, and their characteristics are presented here. CONCLUSION: This new validated French translation of the ESIT-SQ will enable epidemiological and clinical data to be collected in French-speaking populations, and thus compiled and compared with data collected with other versions of this questionnaire already published in other languages.
Asunto(s)
Calidad de Vida , Acúfeno , Humanos , Acúfeno/diagnóstico , Lenguaje , Traducciones , Encuestas y Cuestionarios , Francia , Reproducibilidad de los ResultadosRESUMEN
Thymocytes differentiate in the thymic microenvironment into immunocompetent T cell through the interaction with a variety of accessory cells, including thymic epithelial cells (TEC). TEC plays an important role in the selection process presenting self antigens in association with major histocompatibility complex (MHC) molecules to the maturing T cells. The T cell receptor recognizes the self antigen-MHC complex, but other surface molecules help stabilize this interaction. Thus, the CD2/LFA-3 and LFA-1/intercellular adhesion molecule 1 pairs have been shown to participate in the binding between lymphoid cells and TEC. Here we describe an integrin of the very late activation antigen subfamily composed by the known beta 1 chain and by a novel alpha chain. This adhesion molecule is expressed on the surface of medullary TEC and is involved in the adhesion between TEC and thymocytes, but not peripheral blood T lymphocytes.
Asunto(s)
Adhesión Celular , Integrinas/fisiología , Timo/citología , Anticuerpos Monoclonales/inmunología , Células Cultivadas , Células Epiteliales , Epitelio/química , Humanos , Técnicas In Vitro , Integrinas/química , Integrinas/inmunología , Sustancias Macromoleculares , Peso Molecular , Pruebas de Precipitina , Linfocitos T/citologíaRESUMEN
Evidence-based medicine has enabled to approach disease in a more rational and scientific way. Clinical research has identified behaviours and risk factors that could cause disease often "silent" at the beginning, such as diabetes. Despite the clear impact of these evidences on public health, it seems that the individual risk perception level remains weak. To mention as well, the health professionals very often have a different views, which makes it difficult to communicate the risk with patients. In this article we describe the principles of risk perception, the diabetes related risk perception concerning cardiovascular complications, and suggest some practical strategies and tools which could improve risk communication in the everyday practice.
Asunto(s)
Enfermedades Cardiovasculares/etiología , Comunicación , Complicaciones de la Diabetes , Educación del Paciente como Asunto , Diabetes Mellitus Tipo 2/complicaciones , Medicina Basada en la Evidencia , Conocimientos, Actitudes y Práctica en Salud , Humanos , Percepción , Relaciones Médico-Paciente , Medición de Riesgo , Factores de Riesgo , Asunción de RiesgosRESUMEN
The aim of this article is to propose an anthropological point of view about informed consent in medicine. This quest for legitimacy should be read as a relational and social construction. In the heart of clinical complexity we find on one side various techniques employed by the medical community to validate research and to obtain the consent of patients. On the other side patients offer plural and subjective answers due to the doctor patient hierarchical and long relationship. Between constraints and freedoms, informed consent brings to light social relation.
Asunto(s)
Investigación Biomédica/ética , Consentimiento Informado , Humanos , Relaciones Médico-Paciente/ética , Responsabilidad SocialRESUMEN
The recent ACCORD and DIAD studies revealed results which could modify treatments and the screening of diabetes vascular complications. Indeed, ACCORD shows no benefit on the prevention of diabetes vascular complications by aggressive treatment of hypertension or the combined treatment of the dyslipidemia. The intensive treatment of the blood glucose, if associated with severe hypoglycemias, increases mortality. DIAD revealed 20% of silent myocardial ischaemia in diabetic patients but no beneficial effect on the cardiovascular mortality. A careful reading of these studies in the light of long term studies such as UKPDS and STENO reveals that these negative results are generated by a too short follow-up and too aggressive objectives. The long term studies reveal that more realistic objectives remain beneficial.
Asunto(s)
Enfermedad Coronaria/diagnóstico , Enfermedad Coronaria/etiología , Diabetes Mellitus Tipo 2/complicaciones , Enfermedad Coronaria/epidemiología , Enfermedad Coronaria/prevención & control , Dislipidemias/complicaciones , Dislipidemias/tratamiento farmacológico , Medicina Basada en la Evidencia , Fenofibrato/uso terapéutico , Humanos , Hipertensión/complicaciones , Hipertensión/tratamiento farmacológico , Hipolipemiantes/uso terapéutico , Tamizaje Masivo , Ensayos Clínicos Controlados Aleatorios como Asunto , Factores de RiesgoRESUMEN
Primary angiosarcoma is a rare type of breast cancer, the diagnosis is difficult to establish and it has the worst prognostic of all breast malignancies. Two cases of primary breast angiosarcoma have been observed at the centre Henry Kaplan of Tours and at the hospital La Source of Orleans since 2001. Based on a literature review, we analyse the epidemiological, pathological, clinical, diagnostic and treatment aspect of this type of cancer. Mastectomy is the reference treatment and the benefit of radiotherapy and chemotherapy remains to be demonstrated.
Asunto(s)
Neoplasias de la Mama/patología , Hemangiosarcoma/patología , Adulto , Neoplasias de la Mama/terapia , Quimioterapia Adyuvante , Resultado Fatal , Femenino , Hemangiosarcoma/terapia , Humanos , Mastectomía , Persona de Mediana Edad , Metástasis de la Neoplasia , Recurrencia Local de Neoplasia , Radioterapia AdyuvanteRESUMEN
Soil sorption processes largely control the environmental fate of herbicides. Therefore, accuracy of sorption parameters is crucial for accurate prediction of herbicide mobility in agricultural soils. A combined experimental and statistical study was performed to investigate the small-scale spatial variability of sorption parameters for atrazine and dinoseb in soils and to establish the number of samples needed to provide a value of the distribution coefficient (K(d)) next to the mean, with a given precision. The study explored sorption properties of the two herbicides in subsurface samples collected from four pits distributed along a transect of an alluvial soil; two to four samples were taken at about 30 cm apart at each sampling location. When considering all the data, the distribution coefficients were found to be normally and log-normally distributed for atrazine and dinoseb, respectively; the CVs were relatively high (close to 50% for dinoseb and 40% for atrazine). When analyzed horizon by horizon, the data revealed distribution coefficients normally distributed for both herbicides, whatever the soil layer, with lower CVs. The K(d) values were shown to vary considerably between samples collected at very short distance (a few centimeters), suggesting that taking a single soil sample to determine sorption properties through batch experiments can lead to highly unrepresentative results and to poor sorption/mobility predictions.
Asunto(s)
2,4-Dinitrofenol/análogos & derivados , Atrazina/química , Herbicidas/química , Suelo/análisis , 2,4-Dinitrofenol/química , Adsorción , CinéticaRESUMEN
The environment of tRNA 3'-terminus in the 80S ribosomal A and P sites was studied with a tRNA(Asp) analogue that bears a 4-thiouridine residue (s4U) attached to the 3'-terminal adenosine. The tRNA(Asp) analogue was obtained by in vitro T7 transcription followed by crosslinking with [32P]ps4Up and removal of the 3'-terminal phosphate. It was shown that the presence of the additional nucleotide at the 3'-end does not to hinder the codon-dependent binding of the tRNA to the A and P sites of 80S ribosome. Mild UV-irradiation of the ribosomal complexes containing a short appropriately designed mRNA and the tRNA analogue resulted in crosslinking of the analogue exclusively to 28S rRNA. The crosslinking was completely dependent on the presence of s4U in the tRNA analogue. Using hydrolysis of the crosslinked 28S rRNA with RNase H in the presence of deoxyoligomers complementary to various rRNA sequences, we determined that the crosslinking occurred in fragment 4302-4540 of the 28S rRNA. This fragment is evolutionarily conservative and belongs to domain V that is involved in the formation of the peptidyl transferase site in prokaryotic ribosomes. The use of reverse transcription allowed the determination of the tRNA analogue crosslinking in the P site to nucleotides U4461 and U4502, and the analogue in the A site, to nucleotides U4469 and C4507. In addition, nucleotide C4462 was crosslinked to both P site and A site-bound tRNA analogue. An analysis of the results demonstrates that environments of the tRNA 3'-termini are closely similar in both prokaryotic and eukaryotic ribosomes.
Asunto(s)
Reactivos de Enlaces Cruzados/química , ARN Ribosómico 28S/química , ARN de Transferencia de Aspártico/química , Ribonucleasa H/química , Ribosomas/química , Tiouridina/química , Humanos , Rayos UltravioletaRESUMEN
INTRODUCTION: Neural crest (NC) cells differentiate IN VITRO into neuroblasts, precursors of the enteric nervous system (ENS), when stimulated by specific agents. We developed a study aimed at establishing whether NC-derived neuroblasts can survive and colonise IN VIVO when injected into a recipient mouse gut. MATERIALS AND METHODS: The neuroblast precursors of the ENS were obtained from the vagal portion of the neural tubes of 296 CD-1 and GTROSA26 mouse embryos. The embryonic cells of GTROSA26 mice are identifiable through beta-galactosidase activity which allows recognition by blue staining. The host used in this study was the DOM/+ mouse, an animal model for Hirschsprung's disease (aganglionic megacolon). DOM/+ mouse pups (n = 43) received NC-derived cells inoculated into the seromuscular layer of the gut (33/43) or directly into the peritoneal abdominal cavity (10/43). RESULTS: All DOM/+ mice survived the procedure and were sacrificed after 7 or 14 days. Histochemical staining detected implanted cells in all mice. These showed specific myenteric colonisation into the aganglionic and ganglionic gut. CONCLUSION: The striking result of this study was the specific tropism of the injected NC-derived cells to target sites under the action of unknown chemotactic agents. This experimental procedure might represent a possible treatment option for specific forms of human ENS anomaly such as total intestinal aganglionosis.
Asunto(s)
Diferenciación Celular , Células Madre Embrionarias , Sistema Nervioso Entérico/citología , Ganglios/citología , Cresta Neural/citología , Trasplante de Células Madre , Animales , Movimiento Celular , Enfermedad de Hirschsprung/genética , Inmunohistoquímica , Ratones , Ratones Endogámicos C57BL , Ratones Mutantes , Ratones Transgénicos , Modelos AnimalesRESUMEN
Replication protein A (RPA), the nuclear single-stranded DNA binding protein is involved in DNA replication, nucleotide excision repair (NER) and homologous recombination. It is a stable heterotrimer consisting of subunits with molecular masses of 70, 32 and 14 kDa (p70, p32 and p14, respectively). Gapped DNA structures are common intermediates during DNA replication and NER. To analyze the interaction of RPA and its subunits with gapped DNA we designed structures containing 9 and 30 nucleotide gaps with a photoreactive arylazido group at the 3'-end of the upstream oligonucleotide or at the 5'-end of the downstream oligonucleotide. UV crosslinking and subsequent analysis showed that the p70 subunit mainly interacts with the 5'-end of DNA irrespective of DNA structure, while the subunit orientation towards the 3'-end of DNA in the gap structures strongly depends on the gap size. The results are compared with the data obtained previously with the primer-template systems containing 5'- or 3'-protruding DNA strands. Our results suggest a model of polar RPA binding to the gapped DNA.
Asunto(s)
Replicación del ADN , ADN de Cadena Simple/química , Proteínas de Unión al ADN/química , Uridina Trifosfato/análogos & derivados , Azidas/química , Secuencia de Bases , Reactivos de Enlaces Cruzados/química , Daño del ADN , Cartilla de ADN/química , Replicación del ADN/efectos de la radiación , ADN de Cadena Simple/efectos de la radiación , Proteínas de Unión al ADN/efectos de la radiación , Humanos , Datos de Secuencia Molecular , Ácidos Nucleicos Heterodúplex/química , Ácidos Nucleicos Heterodúplex/efectos de la radiación , Proteína de Replicación A , Rayos Ultravioleta , Uridina Trifosfato/químicaRESUMEN
To analyze the interaction of human replication protein A (RPA) and its subunits with the DNA template-primer junction in the DNA replication fork, we designed several template-primer systems differing in the size of the single-stranded template tail (4, 9, 13, 14, 19 and 31 nt). Base substituted photoreactive dNTP analogs-5-[ N -(2-nitro-5-azidobenzoyl)- trans -3-amino-propenyl-1]-2'-deoxyuridine-5'-triphosphate (NAB-4-dUTP) and 5-[ N -[ N -(2-nitro-5-azidobenzoyl)glycyl]- trans -3-aminopropenyl-1]-2'-deoxyuridine-5'-triphosphate (NAB-7-dUTP)-were used as substrates for elongation of radiolabeled primer-template by DNA polymerases in the presence or absence of RPA. Subsequent UV crosslinking showed that the pattern of p32 and p70 RPA subunit labeling, and consequently their interaction with the template-primer junction, is strongly dependent on the template extension length at a particular RPA concentration, as well as on the ratio of RPA to template concentration. Our results suggest a model of changes in the RPA configuration modulating by the length of the template extension in the course of nascent DNA synthesis.
Asunto(s)
Cartilla de ADN/metabolismo , Replicación del ADN/genética , ADN de Cadena Simple/química , ADN de Cadena Simple/metabolismo , Proteínas de Unión al ADN/química , Proteínas de Unión al ADN/metabolismo , Azidas/química , Azidas/metabolismo , Reactivos de Enlaces Cruzados/química , Reactivos de Enlaces Cruzados/metabolismo , ADN/biosíntesis , ADN Helicasas/química , ADN Helicasas/metabolismo , ADN Polimerasa I/metabolismo , ADN Polimerasa beta/metabolismo , Cartilla de ADN/genética , ADN de Cadena Simple/genética , Escherichia coli/enzimología , Humanos , Modelos Biológicos , Peso Molecular , Unión Proteica , Conformación Proteica , Proteína de Replicación A , Moldes Genéticos , Rayos Ultravioleta , Uridina Trifosfato/análogos & derivados , Uridina Trifosfato/química , Uridina Trifosfato/metabolismoRESUMEN
PURPOSE: In 1996, a multicenter randomized study comparing after breast-conservative surgery, sequential vs concurrent adjuvant chemotherapy (CT) with radiation therapy (RT) was initiated (ARCOSEIN study). Seven hundred sixteen patients were included in this trial. After a median follow-up of 6.7 (4.3-9) years, we decided to prospectively evaluate the late effects of these two strategies. PATIENTS AND METHODS: A total of 297 patients were asked to follow-up from the five larger including institutions. Seventy-two percent (214 patients) were eligible for late toxicity. After breast-conserving surgery with axillary dissection, patients were treated either with sequential treatment with CT first followed by RT (arm A) or CT administered concurrently with RT (arm B). In all patients, CT regimen combined mitoxantrone (12 mg/m(2)), 5-FU (500 mg/m(2)), and cyclophosphamide (500 mg/m(2)), 6 cycles (day 1-day 21). In arm B, patients received concurrently the first 3 cycles of CT with RT. In arm A, RT started 3 to 5 weeks after the 6th cycle of CT. Conventional RT was delivered to the whole breast using a 2 Gy-fraction protocol to a total dose of 50 Gy (+/-boost to the primary tumour bed). The assessment of toxicity was blinded to treatment and was graded by the radiation oncologist according to the LENT-SOMA scale. Skin pigmentation was also evaluated using a personal 5-points scoring system (excellent, good, moderate, poor, very poor). RESULTS: Among the 214 evaluated patients, 107 were treated in each arm. The two populations were homogeneous for patients', tumors' and treatment characteristics. Subcutaneous fibrosis (SF), telengectasia (T), skin pigmentation (SP), and breast atrophy (BA) were significantly increased in arm B. Twenty patients experienced grade superior or equal to 2 (SF) in arm B vs five in arm A (P=0.003). Twenty-five and seven patients showed grade superior or equal to 2 (T) in arm B and A, respectively (P=0.001). Forty-four and twenty patients showed grade superior or equal to 2 (BA) in arm B and A, respectively (P=0.0006). Thirty patients experienced grade superior or equal to 3 (SP) in arm B vs fifteen in arm A (P=0.02). No statistical difference was observed between the two arms concerning grade superior or equal to 2 pain, breast oedema, and lymphoedema. No deaths were caused by late toxicity. CONCLUSION: Following breast conserving surgery, the concurrent use of CT with RT is significantly associated with an increase incidence of grade 2 or greater late side effects.
Asunto(s)
Neoplasias de la Mama/cirugía , Mastectomía Segmentaria , Adulto , Anciano , Antineoplásicos/administración & dosificación , Antineoplásicos Alquilantes/administración & dosificación , Protocolos de Quimioterapia Combinada Antineoplásica/uso terapéutico , Atrofia , Mama/efectos de los fármacos , Mama/efectos de la radiación , Neoplasias de la Mama/tratamiento farmacológico , Neoplasias de la Mama/radioterapia , Quimioterapia Adyuvante/efectos adversos , Ciclofosfamida/administración & dosificación , Fraccionamiento de la Dosis de Radiación , Femenino , Fibrosis , Estudios de Seguimiento , Humanos , Escisión del Ganglio Linfático , Persona de Mediana Edad , Mitoxantrona/administración & dosificación , Estudios Prospectivos , Radioterapia Adyuvante/efectos adversos , Método Simple Ciego , Pigmentación de la Piel/efectos de los fármacos , Pigmentación de la Piel/efectos de la radiación , Telangiectasia/inducido químicamente , Telangiectasia/etiologíaRESUMEN
The nucleotides of tRNA(Phe) interacting with the subunits of Thermus thermophilus phenylalanyl-tRNA synthetase (the alpha(2)beta(2) heterotetramer) have been determined by photoaffinity crosslinking of randomly s(4)U-monosubstituted tRNA(Phe) transcripts which retain aminoacylation parameters closely similar to those of the native tRNA(Phe). The thiolated transcripts have been fractionated by affinity electrophoresis and separately crosslinked to the enzyme. Sites of crosslinking to the beta subunit have been identified at positions 33 and 39 and crosslinking sites to the alpha subunit have been localized at positions 20, 45 and 47, using alkaline hydrolysis analysis of the crosslinked proteinase K-treated tRNAs. An additional crosslink to the beta subunit, not identified in the full-length crosslinked tRNAs, has been deduced to occur at position 12, based on the analysis of an unusual (fast migrating) crosslinked product. Nucleotide s(4)U8 of native tRNA(Phe) has been shown to form a minor crosslink to the alpha subunit. Four of the seven crosslinking sites, namely nucleotides 8, 12, 20 and 39, are among those shown to be protected against cleavage by iodine in footprinting experiments; in contrast, only nucleotide 12 is among the contact sites defined in the crystal structure. The data of independent biochemical approaches strongly suggest conformational flexibility of the complex under functional conditions, thus reflecting the importance of macromolecular dynamics for the interaction.
Asunto(s)
Fenilalanina-ARNt Ligasa/metabolismo , ARN de Transferencia de Fenilalanina/metabolismo , Thermus thermophilus/metabolismo , Sitios de Unión , Modelos Moleculares , Fenilalanina-ARNt Ligasa/química , Etiquetas de Fotoafinidad , ARN de Transferencia de Fenilalanina/química , Thermus thermophilus/enzimología , Tiouridina/químicaRESUMEN
The conformation of a hammerhead ribozyme domain, formed between a 35-mer ribozyme and its 14-mer substrate, was studied under cleavage conditions with non-cleavable substrate analogues. Each analogue substrate contained a single 2'-deoxy-4-thiouridine that formed specific intermolecular crosslinks within the ribozyme-substrate complex upon irradiation with 365 nm light. The residues at positions 7 and 8 to 9 (the cleavage site) were found in contact with several bases of the ribozyme 5' conserved region regardless of whether the substrate was all-RNA, with a single deoxynucleotide at the cleavage site, or all-DNA. These contacts were observed in the presence of either 20 mM Mg2+ or 200 mM Na+. The multiple crosslinks generated between the ribozyme central core and each of the three substrates suggest the existence of several folded conformers of the ribozyme. A ribozyme mutation (A28U), which abolishes the catalytic activity, was shown to strongly affect the pattern of crosslinks; this argues for the presence of multiple folded conformers of the ribozyme some of which may be catalytically inactive.
Asunto(s)
Conformación de Ácido Nucleico , ARN Catalítico/química , ARN Catalítico/metabolismo , ARN Viral/metabolismo , Secuencia de Bases , Reactivos de Enlaces Cruzados , ADN/síntesis química , ADN/química , ADN/metabolismo , Desoxiuridina/análogos & derivados , VIH/genética , Datos de Secuencia Molecular , Ácidos Nucleicos Heterodúplex/análisis , ARN Catalítico/síntesis química , ARN Catalítico/genética , ARN Viral/química , ARN Viral/genética , Tiouridina/análogos & derivados , Rayos UltravioletaRESUMEN
The 10.1.2 MoAb reacts with a novel alpha chain that associates with the beta 1 integrin chain and is widely distributed among epithelial and endothelial cells of human adult and fetal tissues. In the epidermis and in other squamous epithelia, alpha 10.1.2 chains are expressed exclusively in the basal cell layer. Here we describe the immunohistochemical localization of alpha 10.1.2 in human epidermis, in other squamous epithelia, as well as in cultured keratinocytes. alpha 10.1.2 chain localization has also been investigated in a variety of non-neoplastic and neoplastic lesions of the skin, the uterine cervix, and the lung. We show that alpha 10.1.2 chains retain their basal keratinocyte localization in hyperplastic skin diseases and in benign tumors of the epidermis and that they are strongly expressed in basal cell carcinomas. In contrast, alpha 10.1.2 expression is decreased in keratinocytes that differentiate in vitro and is lost in epidermal dysplastic conditions, in the invading front of squamous cell carcinomas of the epidermis, in microinvasive cervical cancers, and in well-differentiated squamous lung tumors. These findings indicate that alpha 10.1.2 beta 1 integrin is downregulated during keratinocyte differentiation in vitro and in vivo. Moreover, lack of alpha 10.1.2 expression in basal cells of squamous epithelia is associated with early dysplastic changes and with the acquisition of invasive capacity.
Asunto(s)
Carcinoma Basocelular/química , Carcinoma de Células Escamosas/química , Integrinas/análisis , Neoplasias Cutáneas/química , Piel/química , Piel/citología , Anticuerpos Monoclonales/análisis , Anticuerpos Monoclonales/inmunología , Biopsia , Carcinoma Basocelular/patología , Carcinoma de Células Escamosas/patología , Diferenciación Celular , División Celular , Transformación Celular Neoplásica/patología , Células Cultivadas , Células Epiteliales , Epitelio/química , Epitelio/embriología , Femenino , Feto/patología , Técnica del Anticuerpo Fluorescente , Humanos , Inmunohistoquímica , Integrina beta1 , Integrinas/inmunología , Queratinocitos/química , Queratinocitos/patología , Queratoacantoma/patología , Queratosis/patología , Leiomioma/química , Leiomioma/patología , Neoplasias Pulmonares/química , Neoplasias Pulmonares/patología , Microscopía Inmunoelectrónica , Piel/embriología , Enfermedades de la Piel/patología , Neoplasias Cutáneas/patología , Neoplasias del Cuello Uterino/química , Neoplasias del Cuello Uterino/patología , Neoplasias Uterinas/química , Neoplasias Uterinas/patologíaRESUMEN
s4U-containing transcripts of tRNA(Phe) gene have been prepared by complete substitution of 16 U residues or by random incorporation of s4U residues followed by affinity electrophoresis isolation of s4U-monosubstituted tRNA transcripts. Both analogs have been cross-linked to Thermus thermophilus phenylalanyl-tRNA synthetase (PheRS) and the specificity of the cross-linking has been demonstrated. Functional activity of the covalent complex of PheRS with the s4U-monosubstituted transcript has been shown by aminoacylation of 60% of the enzyme-cross-linked tRNA. This is the first instance in which biological activity of aminoacyl-tRNA synthetase and cross-linked tRNA in a specific complex has been revealed.
Asunto(s)
Fenilalanina-ARNt Ligasa/metabolismo , ARN de Transferencia de Fenilalanina/metabolismo , Acilación , Conformación de Ácido Nucleico , ARN de Transferencia de Fenilalanina/química , Thermus thermophilus/metabolismo , Tiouridina/químicaRESUMEN
To analyze the influence of single-stranded template extension of DNA duplex on the conformation of human replication protein A (RPA) bound to DNA we have designed two template-primer systems differing by the size of the single-stranded template tail (9 and 19 nucleotides (nt)). Base-substituted photoreactive dUTP analogs were used as substrates for elongation of radiolabeled template-primer by DNA polymerase beta in the absence or in the presence of RPA. Following UV-crosslinking it was demonstrated that the pattern of RPA subunit labeling and consequently RPA arrangement near the 3'-end of the primer is strongly dependent upon the length of the template extension.
Asunto(s)
Cartilla de ADN/química , Proteínas de Unión al ADN/química , Conformación Proteica , Reactivos de Enlaces Cruzados/química , Replicación del ADN , Humanos , Etiquetas de Fotoafinidad , Proteína de Replicación A , Moldes GenéticosRESUMEN
Telomerase is a ribonucleoprotein responsible for maintaining telomeres during the cell cycle [1,2]. Here we describe a two-step purification procedure for the Saccharomyces cerevisiae telomerase complex. We have found that the properties (processivity, nuclease activity) of telomerase depend on the isolation procedure. Using a cross-linking approach, we have revealed several proteins that could be components of the telomerase complex. Furthermore, spectra of cross-linked proteins differ in processive and non-processive telomerase complexes.