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1.
SAR QSAR Environ Res ; 33(10): 753-778, 2022 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-36318662

RESUMO

Since interleukin-8 (IL-8/CXCL8) and its receptor, CXCR1 and CXCR2, were known in the early 1990s, biological pathways related to these proteins were proven to have high clinical value in cancer and inflammatory/autoimmune conditions treatment. Recently, IL-8 has been identified as biomarker for severe COVID-19 patients and COVID-19 prognosis. Boyles et al. (mAbs 12 (2020), pp. 1831880) have published a high-resolution X-ray crystal structure of the LY3041658 Fab in a complex human CXCL8. They described the ability to bind to IL-8 and the blocking of IL-8/its receptors interaction by the LY3041658 monoclonal antibody. Therefore, the study has been designed to identify potential small molecules inhibiting interleukin-8 by targeting LY3041658/IL-8 complex structure using an in silico approach. A structure­based pharmacophore and molecular docking models of the protein active site cavity were generated to identify possible candidates, followed by virtual screening with the ZINC database. ADME analysis of hit compounds was also conducted. Molecular dynamics simulations were then performed to survey the behaviour and stability of the ligand-protein complexes. Furthermore, the MM/PBSA technique has been utilized to evaluate the free binding energy. The final data confirmed that one newly obtained compound, ZINC21882765, may serve as the best potential inhibitor for IL-8.


Assuntos
Tratamento Farmacológico da COVID-19 , Interleucina-8 , Humanos , Simulação de Acoplamento Molecular , Relação Quantitativa Estrutura-Atividade , Simulação de Dinâmica Molecular , Ligantes
2.
Vavilovskii Zhurnal Genet Selektsii ; 26(2): 146-152, 2022 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-35434488

RESUMO

Correlations between the morphological features of f lower buds and the developmental stages of the male gametophyte are of great practical interest as a reliable marker that accelerates and simplif ies the selection of appropriate plant material for isolated microspore culture. Microspore culture enables one to quickly obtain many pure lines of different vegetable crops, but it has not yet been widely applied in the melon (Cucumis melo L.). To successfully apply this technique in a new culture, one has to optimize many of its elements: f irst, f ind the biological markers for selecting the f lower buds containing the microspores of certain development stages. The paper presents the results of research estimating the correlations between the length and diameter of the f lower buds, the length of the visual part of the corolla, the length of the anthers and the development stages of the male gametophyte in the F1 hybrid of the Kim Hong Ngoc melon. The strongest correlation (CC = 0.885) was found for the f lower bed diameter and a strong correlation (CC = 0.880), for the bud length. The corolla's visual part was a less reliable morphological feature, and the anther's length should not be used as a parameter to predict the developmental stages of the melon's male gametophyte. It was also found that one anther could contain the microspores and pollen grains of different developmental stages. In the f lower buds less than 4 mm in length and 1.51 ± 0.02 mm in diameter prevailed tetrads, and in the buds 4.0-4.9 mm in length and 2.30 ± 0.02 mm in diameter, early microspores. The microspores of a middle stage of development prevailed in the f lower buds 5.0-5.9 mm in length and 2.32 ± 0.00 mm in diameter; mid and late vacuolated microspores, in the buds 6.0-8.9 mm in length and 2.96 ± 0.37 mm in diameter; and two-celled pollen, in the buds more than 9 mm in length and more than 3.97 ± 0.34 mm in diameter.

3.
ACS Synth Biol ; 9(6): 1406-1417, 2020 06 19.
Artigo em Inglês | MEDLINE | ID: mdl-32496044

RESUMO

Riboswitches are RNA regulatory elements that bind specific ligands to control gene expression. Because of their modular composition, where a ligand-sensing aptamer domain is combined with an expression platform, riboswitches offer unique tools for synthetic biology applications. Here we took a mutational approach to determine functionally important nucleotide residues in the thiamine pyrophosphate (TPP) riboswitch in the THI4 gene of the model alga Chlamydomonas reinhardtii, allowing us to carry out aptamer swap using THIC aptamers from Chlamydomonas and Arabidopsis thaliana. These chimeric riboswitches displayed a distinct specificity and dynamic range of responses to different ligands. Our studies demonstrate ease of assembly as 5'UTR DNA parts, predictability of output, and utility for controlled production of a high-value compound in Chlamydomonas. The simplicity of riboswitch incorporation in current design platforms will facilitate the generation of genetic circuits to advance synthetic biology and metabolic engineering of microalgae.


Assuntos
Chlamydomonas/metabolismo , Engenharia Metabólica/métodos , Riboswitch/genética , Regiões 5' não Traduzidas , Proteínas de Algas/genética , Proteínas de Algas/metabolismo , Aptâmeros de Nucleotídeos/genética , Aptâmeros de Nucleotídeos/metabolismo , Expressão Gênica , Mutagênese , Tiamina Pirofosfato/metabolismo , Raios Ultravioleta
4.
RSC Adv ; 9(29): 16784-16789, 2019 May 24.
Artigo em Inglês | MEDLINE | ID: mdl-35516388

RESUMO

A new Fe-based metal-organic framework (MOF), termed Fe-TBAPy Fe2(OH)2(TBAPy)·4.4H2O, was solvothermally synthesized. Structural analysis revealed that Fe-TBAPy is built from [Fe(OH)(CO2)2]∞ rod-shaped SBUs (SBUs = secondary building units) and 1,3,6,8-tetrakis(p-benzoate)pyrene (TBAPy4-) linker to form the frz topological structure highlighted by 7 Å channels and 3.4 Å narrow pores sandwiching between the pyrene cores of TBAPy4-. Consequently, Fe-TBAPy was used as a recyclable heterogeneous catalyst for benzene hydroxylation. Remarkably, the catalysis reaction resulted in high phenol yield and selectivity of 64.5% and 92.9%, respectively, which are higher than that of the other Fe-based MOFs and comparable with those of the best-performing heterogeneous catalysts for benzene hydroxylation. This finding demonstrated the potential for the design of MOFs with enhancing catalysis activity for benzene hydroxylation.

5.
RSC Adv ; 9(6): 3345-3350, 2019 Jan 22.
Artigo em Inglês | MEDLINE | ID: mdl-35518972

RESUMO

Neodymium-based Ziegler-Natta type catalytic systems are known to produce polydienes with high cis-1,4 content. It is generally believed that in Ziegler-Natta catalytic systems, a halide or pseudohalide, whether in the catalyst itself or a separate source, is required for the success of the polymerization. In this work, we have synthesized an unusual halide-free neodymium diethyl phosphate catalyst for diene polymerization. This neodymium complex combined with triisobutylaluminum (TIBA), formed a binary catalytic system and was used to polymerize ß-myrcene. The catalytic system displays high stereospecificity and produces poly(ß-myrcene) with 96% cis-1,4 content and a relatively narrow molecular weight distribution (M w/M n = 1.80). Also, kinetic studies indicated the catalytic system gives a pseudo-living polymerization. The block copolymer poly(ß-myrcene)-b-poly(isoprene) was successfully synthesized by sequential monomer addition, further demonstrating the pseudo-living nature of polymerization with the neodymium diethyl phosphate catalyst.

6.
Ann Burns Fire Disasters ; 32(4): 294-300, 2019 Dec 31.
Artigo em Inglês | MEDLINE | ID: mdl-32431580

RESUMO

Radiation-induced ulcers are a late-stage skin reaction after radiation therapy for cancer treatment. The present study examined the possibility of using a single-stage reconstructive procedure to manage radiation-related wounds. This prospective study recruited 30 participants who underwent radiation treatment for cancer or hemangioma. The patients ranged in age from 15 to 80 years. They were admitted to the Plastic, Reconstructive, and Regenerative Centre of Viet Nam National Burn Hospital from October 2013 to September 2017. For each patient, the surgeons discussed which reconstructive method would yield the best outcome. Patients' demographic data and information on the radiation-induced ulcer, the reconstructive method used, complications, and length of hospital stay were recorded. The mean age of all participants was 50 ± 36.3 years, and female patients were predominant (83.3%). Eighteen perforator flaps, five random-pattern flaps, three free flaps, three tissue expander flaps, and one full-thickness skin graft were employed, with no instances of recurrence or complications, except for total flap loss in two cases. The median length of stay was 43 days. These data suggest that immediate reconstruction may be a valuable option for managing radiation-induced ulcers.


Les radiodermites chroniques ulcéreuses sont une complication tardive des radiothérapies pour cancer. Cette étude prospective, réalisée dans le service de chirurgie plastique, reconstructive et régénérative de l'hôpital brûlologique national du Viêtnam d'octobre 2013 à septembre 2017, a examiné la possibilité de leur reconstruction en un seul temps chirurgical. Elle a concerné 30 patients irradiés pour cancer ou hémangiome, la meilleure méthode de reconstruction ayant à chaque fois été recherchée par le chirurgien. Les données démographiques, celles de la lésion, la méthode de reconstruction choisie, la durée de séjour et les complications ont été colligées. L'âge moyen était de 50 +/- 36,3 ans (15 ­ 80) et l'échantillon comprenait 83,3% de femmes. Nous avons réalisé 18 lambeaux perforants, 5 lambeaux au hasard, 3 lambeaux libres, 3 lambeaux après expansion et 1 greffe de peau totale. Deux lambeaux ont complétement nécrosé, il n'y a pas eu de récidive. La durée médiane de séjour était de 45 j. La reconstruction en 1 temps semble donc être possible dans le traitement des radiodermites chroniques.

7.
Epidemiol Infect ; 144(1): 35-44, 2016 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-25997360

RESUMO

Porcine reproductive and respiratory syndrome (PRRS) outbreaks in pigs are associated with increased susceptibility of pigs to secondary bacterial infections, including Streptococcus suis - an important zoonotic pathogen causing bacterial meningitis in humans. This case-control study examined the association between human S. suis infection and PRRS outbreaks in pigs in northern Vietnam. We included 90 S. suis case-patients and 183 non-S. suis sepsis controls from a referral hospital in Hanoi in 2010, a period of major PRRS epizootics in Vietnam. PRRS exposure was determined using data from the National Centre of Veterinary Diagnosis. By univariate analysis, significantly more S. suis patients were reported residing in or adjacent to a PRRS district compared to controls [odds ratio (OR) 2·82, 95% confidence interval (CI) 1·35-5·89 and OR 3·15, 95% CI 1·62-6·15, respectively]. Only residency in adjacent districts remained significantly associated with risk of S. suis infection after adjusting for sex, occupation, and eating practices. SaTScan analysis showed a possible cluster of S. suis infection in humans around PRRS confirmed locations during the March-August period. The findings indicate an epidemiological association between PRRS in pigs and S. suis infections in humans. Effective strategies to strengthen control of PRRS in pigs may help reduce transmission of S. suis infection to humans.


Assuntos
Surtos de Doenças/veterinária , Síndrome Respiratória e Reprodutiva Suína/epidemiologia , Vírus da Síndrome Respiratória e Reprodutiva Suína/fisiologia , Infecções Estreptocócicas/epidemiologia , Streptococcus suis/fisiologia , Animais , Humanos , Síndrome Respiratória e Reprodutiva Suína/virologia , Fatores de Risco , Infecções Estreptocócicas/microbiologia , Suínos , Vietnã/epidemiologia
8.
Biophys J ; 101(9): 2170-7, 2011 Nov 02.
Artigo em Inglês | MEDLINE | ID: mdl-22067155

RESUMO

Calmodulin (CaM) binding to the type 2 ryanodine receptor (RyR2) regulates Ca release from the cardiac sarcoplasmic reticulum (SR). However, the structural basis of CaM regulation of the RyR2 is poorly defined, and the presence of other potential CaM binding partners in cardiac myocytes complicates resolution of CaM's regulatory interactions with RyR2. Here, we show that a fluorescence-resonance-energy-transfer (FRET)-based approach can effectively resolve RyR2 CaM binding, both in isolated SR membrane vesicles and in permeabilized ventricular myocytes. A small FRET donor was targeted to the RyR2 cytoplasmic assembly via fluorescent labeling of the FKBP12.6 subunit. Acceptor fluorophore was attached at discrete positions within either the N- or the C-lobe of CaM. FRET between FKBP12.6 and CaM bound to SR vesicles indicated CaM binding at a single high-affinity site within 60 Å of FKBP12.6. Micromolar Ca increased the apparent affinity of CaM binding and slowed CaM dissociation, but did not significantly affect maximal FRET efficiency at saturating CaM. FRET was strongest when the acceptor was attached at either of two positions within CaM's N-lobe versus sites in CaM's C-lobe, providing CaM orientation information. In permeabilized ventricular myocytes, FKBP12.6 and CaM colocalized to Z-lines, and the efficiency of energy transfer to both the N- and C-lobes of CaM was comparable to that observed in SR vesicle experiments. Results also indicate that both the location and orientation of CaM binding on the RyR2 are very similar to the skeletal muscle RyR1 isoform. Specific binding of CaM to functional RyR2 channels in the cardiac myocyte environment can be monitored using FKBP biosensors and FRET.


Assuntos
Calmodulina/metabolismo , Transferência Ressonante de Energia de Fluorescência , Miocárdio/metabolismo , Canal de Liberação de Cálcio do Receptor de Rianodina/metabolismo , Animais , Permeabilidade da Membrana Celular/efeitos dos fármacos , Proteínas Luminescentes/metabolismo , Miócitos Cardíacos/citologia , Miócitos Cardíacos/efeitos dos fármacos , Miócitos Cardíacos/metabolismo , Ligação Proteica/efeitos dos fármacos , Ratos , Retículo Sarcoplasmático/efeitos dos fármacos , Retículo Sarcoplasmático/metabolismo , Sirolimo/farmacologia , Suramina/farmacologia , Sus scrofa , Proteínas de Ligação a Tacrolimo/metabolismo
9.
J Nucl Med Technol ; 38(1): 28-31, 2010 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-20159928

RESUMO

UNLABELLED: The development of small-field-of-view, breast-optimized, gamma-camera designed for breast scintigraphy has resulted in improved breast lesion detection-particularly for lesions smaller than 1 cm. However, unlike with the standard gamma-camera, these images do not include the axilla within the field of view. METHODS: Because of the effectiveness of breast scintigraphy using (99m)Tc-sestamibi in the detection of axillary lymph node metastases, this article describes the development of an axillary imaging protocol for these small-field-of-view systems. RESULTS: In addition, it describes how the improved resolution of these systems affects imaging of the axilla and reports observed, normal variants. CONCLUSION: Last, several example patient cases are discussed, describing both the impact and the limitations of this imaging protocol.


Assuntos
Mama/diagnóstico por imagem , Linfonodos/diagnóstico por imagem , Cintilografia/métodos , Mama/patologia , Mama/cirurgia , Feminino , Humanos , Especificidade de Órgãos , Postura , Cintilografia/instrumentação
10.
Oncogene ; 29(8): 1155-66, 2010 Feb 25.
Artigo em Inglês | MEDLINE | ID: mdl-19935715

RESUMO

The p53 tumor suppressor protein induces apoptosis in response to genotoxic and environmental stresses. Recent studies have revealed the existence of a transcription-independent mitochondrial p53 apoptotic pathway; however, the mechanism that regulates its translocation to the mitochondria has been unknown. In this study, we show that the tumor suppressor Tid1 forms a complex with p53 under hypoxic conditions that directs p53 translocation to the mitochondria and the subsequent initiation of the mitochondrial apoptosis pathway. Loss of Tid1 expression abrogated p53 translocation to the mitochondria and inhibited apoptosis, whereas the over-expression of Tid1 promoted p53 mitochondrial localization and apoptosis. Tid1's mitochondrial signal sequence and DnaJ domain were both required for the movement of the p53-Tid1 complex from the cytosol to the mitochondria. When Tid is over-expressed in cancer cell lines expressing mutant p53 isoforms defective in transcriptional activity, mitochondrial localization and pro-apoptotic activities of the mutant p53 proteins was restored. Our results establish Tid1 as a novel regulator of p53-mediated apoptosis, and suggest that therapies designed to enhance Tid1's function in promoting mitochondrial localization of p53 and apoptosis could be an effective therapy in many cancers.


Assuntos
Apoptose/fisiologia , Proteínas de Choque Térmico HSP40/farmacologia , Mitocôndrias/efeitos dos fármacos , Neoplasias/patologia , Transporte Proteico/efeitos dos fármacos , Proteína Supressora de Tumor p53/fisiologia , Citosol/química , Regulação Neoplásica da Expressão Gênica , Genes Supressores de Tumor , Genes p53/fisiologia , Proteínas de Choque Térmico HSP40/genética , Proteínas de Choque Térmico HSP40/metabolismo , Humanos , Mitocôndrias/metabolismo , Neoplasias/metabolismo , Transporte Proteico/fisiologia , Proteínas Proto-Oncogênicas c-bcl-2/farmacologia , Proteína Supressora de Tumor p53/metabolismo
11.
J Nucl Med Technol ; 37(4): 201-5, 2009 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-19914975

RESUMO

Breast-specific gamma-imaging (BSGI), also known as molecular breast imaging, is breast scintigraphy using a small-field-of-view gamma-camera and (99m)Tc-sestamibi. There are many different types of breast cancer, and many have characteristics making them challenging to detect by mammography and ultrasound. BSGI is a cost-effective, highly sensitive and specific technique that complements other imaging modalities currently being used to identify malignant lesions in the breast. Using the current Society of Nuclear Medicine guidelines for breast scintigraphy, Legacy Good Samaritan Hospital began conducting BSGI, breast scintigraphy with a breast-optimized gamma-camera. In our experience, optimal imaging has been conducted in the Breast Center by a nuclear medicine technologist. In addition, the breast radiologists read the BSGI images in correlation with the mammograms, ultrasounds, and other imaging studies performed. By modifying the current Society of Nuclear Medicine protocol to adapt it to the practice of breast scintigraphy with these new systems and by providing image interpretation in conjunction with the other breast imaging studies, our center has found BSGI to be a valuable adjunctive procedure in the diagnosis of breast cancer. The development of a small-field-of-view gamma-camera, designed to optimize breast imaging, has resulted in improved detection capabilities, particularly for lesions less than 1 cm. Our experience with this procedure has proven to aid in the clinical work-up of many of our breast patients. After reading this article, the reader should understand the history of breast scintigraphy, the pharmaceutical used, patient preparation and positioning, imaging protocol guidelines, clinical indications, and the role of breast scintigraphy in breast cancer diagnosis.


Assuntos
Mama/diagnóstico por imagem , Câmaras gama , Cintilografia/métodos , Tecnécio Tc 99m Sestamibi , Mama/patologia , Neoplasias da Mama/diagnóstico por imagem , Neoplasias da Mama/patologia , Feminino , Humanos , Especificidade de Órgãos , Cintilografia/instrumentação
12.
J Food Sci ; 73(4): E176-82, 2008 May.
Artigo em Inglês | MEDLINE | ID: mdl-18460127

RESUMO

The color of aqueous solutions obtained by heating carrot (Daucus carota L.) roots in water ("stocks") is different when the thermal treatment is applied with or without exposure to light. CIE L*, a*, and b* scale values of stocks processed for different times were recorded and 4 patterns were initially observed. To explain the 1st part of this evolution (patterns 1 and 2), pectin extraction and beta-elimination in stocks were studied. Light dependence was investigated to explain patterns 3 and 4. A model with 2 compounds is proposed to explain all the color variations.


Assuntos
Cor , Daucus carota , Manipulação de Alimentos/métodos , Temperatura Alta , Luz , Raízes de Plantas , Colorimetria , Daucus carota/química , Ácidos Hexurônicos/análise , Concentração de Íons de Hidrogênio , Pectinas/análise , Raízes de Plantas/química , Soluções , Água
13.
Gynecol Obstet Fertil ; 32(5): 404-8, 2004 May.
Artigo em Francês | MEDLINE | ID: mdl-15177210

RESUMO

OBJECTIVE: The aim of the study is to analyze the histological-cytological correlations for Pap smears having detected cancer or high-grade squamous intra-epithelial lesion (HSIL) of the cervix. PATIENTS AND METHOD: The study about 311 women is retrospective. The average age is 36.4 years. Group 1 (histological diagnosis of high-grade or invasive lesion) includes 244 women (77.5%). Group 2 (histological diagnosis other than high-grade or invasive lesion) includes 37 women (11.9%) with a presumed diagnosis of HSIL. Group 3 (absence of histological follow-up) includes 30 women (9.6%) with a presumed diagnosis of HSIL. RESULTS: In group 1, the presumed cytological diagnosis is HSIL in 229 cases, squamous carcinoma in 11 cases and adenocarcinoma in two cases. In this group, the average delay between the Pap smear and the first histology is equal to two months. It is longer than 6 months in seven cases. The diagnosis of cancer or high-grade lesion is confirmed histologically on a first biopsy of the cervix in 196 cases, a second or a third biopsy in 10 cases, an endocervical curettage in six cases and a surgical specimen in 32 cases. In the group 2, the histological diagnosis is normal-benign in 14 cases (presumed cytological false positives) and condyloma-CIN 1 in 23 cases (presumed overevaluations). DISCUSSION AND CONCLUSION: Results highlight benefits of interactive exchanges between clinicians and pathologists, and the necessity of review of discordant cases by several pathologists in due time, with written comments and coding of the conclusions of the review. Histological follow-up is late or not done in some women.


Assuntos
Teste de Papanicolaou , Neoplasias do Colo do Útero/patologia , Esfregaço Vaginal , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Carcinoma de Células Escamosas/patologia , Feminino , Humanos , Pessoa de Meia-Idade , Estudos Retrospectivos , Displasia do Colo do Útero/patologia
14.
Biochem Biophys Res Commun ; 256(2): 299-306, 1999 Mar 16.
Artigo em Inglês | MEDLINE | ID: mdl-10079180

RESUMO

Epithelin/granulin growth factor is synthesized as a 593 amino acid precursor protein that contains 7.5 imperfectly conserved repeats of approximately 57 amino acids. Processed epithelin/granulin peptides have been isolated from vertebrate/invertebrate species and are growth factors implicated in epithelial and haemic cell function. Here they are identified as Human Immunodeficiency Virus (HIV) Tat binding proteins using the yeast two-hybrid assay. Intracellularly in yeast, mutation of selected cysteines in an epithelin/granulin dimeric repeat caused loss of binding to Tat exon 1. In vitro binding of HIV-1 and HIV-2 Tat to epithelin/granulin dimeric and monomeric repeats was also observed by GST-glutathione bead "pulldown" assays. Because Tat is actively secreted from HIV-infected cells and has been shown to serve as a mitogenic factor for angiogenesis and for Kaposi-like cells, our observations suggest that epithelin/granulin growth factors may function as biologically important extracellular Tat co-factors.


Assuntos
Produtos do Gene tat/metabolismo , Substâncias de Crescimento/metabolismo , HIV-1/metabolismo , HIV-2/metabolismo , Peptídeos e Proteínas de Sinalização Intercelular , Sequência de Aminoácidos , Substituição de Aminoácidos , Sítios de Ligação , Sequência Conservada/genética , Cisteína/genética , Cisteína/metabolismo , Éxons/genética , Biblioteca Gênica , Produtos do Gene tat/genética , Granulinas , Substâncias de Crescimento/genética , HIV-1/genética , HIV-2/genética , Humanos , Leucócitos Mononucleares/metabolismo , Dados de Sequência Molecular , Proteínas Nucleares/genética , Proteínas Nucleares/metabolismo , Ligação Proteica , RNA Mensageiro/análise , Proteínas de Ligação a RNA , Proteínas Recombinantes de Fusão/genética , Proteínas Recombinantes de Fusão/metabolismo , Saccharomyces cerevisiae/genética , Deleção de Sequência , Fatores de Processamento de Serina-Arginina , Células Tumorais Cultivadas , Proteínas Virais/genética , Proteínas Virais/metabolismo , Produtos do Gene tat do Vírus da Imunodeficiência Humana
15.
Mol Endocrinol ; 11(2): 203-9, 1997 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-9013767

RESUMO

The proglucagon gene is expressed in a highly cell-specific manner in islet and enteroendocrine cells. DNA sequences within the proximal proglucagon G1 promoter region bind the homeobox protein cdx-2/3, and cdx-2/3 activates the proglucagon promoter in fibroblasts. We show here that cdx-2/3 activates the proglucagon promoter in both islet (InR1-G9) and enteroendocrine (STC-1 and GLUTag) cell lines. Furthermore, transfected cdx-2/3 increased the levels of endogenous proglucagon mRNA transcripts in both transient and stable transfections of InR1-G9 islet cells. The cdx-2/3-dependent induction of endogenous proglucagon mRNA transcripts in stable islet lines was associated with a corresponding increase in the transcriptional activity of proglucagon promoter-luciferase plasmids. An amino-terminally truncated cdx-2/3 derivative containing the homeodomain and carboxy-terminal region of the molecule inhibited both the cdx-2/3 activation of the proglucagon promoter and the induction of endogenous proglucagon mRNA transcripts. These observations demonstrate that cdx-2/3, acting through the proximal G1 element, is a major transcriptional determinant of cell-specific proglucagon gene expression in pancreatic islet cells.


Assuntos
Glucagon/genética , Proteínas de Homeodomínio , Proteínas de Homeodomínio/metabolismo , Ilhotas Pancreáticas/fisiologia , Proteínas do Tecido Nervoso , Precursores de Proteínas/genética , Animais , Sítios de Ligação , Northern Blotting , Fator de Transcrição CDX2 , Células Cultivadas , Fibroblastos/metabolismo , Regulação da Expressão Gênica , Glucagon/metabolismo , Proteínas de Homeodomínio/genética , Intestinos/citologia , Intestinos/fisiologia , Ilhotas Pancreáticas/citologia , Proteínas com Homeodomínio LIM , Luciferases/genética , Luciferases/metabolismo , Camundongos , Plasmídeos , Reação em Cadeia da Polimerase , Proglucagon , Regiões Promotoras Genéticas , Precursores de Proteínas/metabolismo , RNA Mensageiro/biossíntese , Proteínas Recombinantes/genética , Proteínas Recombinantes/metabolismo , Transativadores , Fatores de Transcrição , Transcrição Gênica , Transfecção
16.
Clin Immunol Immunopathol ; 78(2): 172-9, 1996 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-8625559

RESUMO

Prior to the AIDS epidemic, Kaposi's sarcoma (KS) was a rare neoplasm. However, in the context of immunosuppression, cutaneous KS lesions more frequently develop and express various surface molecules recognized by T cells such as intercellular adhesion molecule-1 (ICAM-1; CD54) and HLA-DR. The KS tumor cells are thought to arise locally from endothelial cells via a transdifferentiation process. To determine if KS tumor cells can stimulate resting T cell proliferation, we asked whether the tumor cells express the critically important T cell costimulatory molecules B7-1 (CD-80) and B7-2 (CD-86). In contrast to cytokine-activated endothelial cells, which were induced to express B7-1, but not B7-2 and could function in bacteria-derived superantigen-driven T cell proliferation, four different KS tumor cell lines failed to express either B7-1 or B7-2 and were unable to stimulate allogeneic T cell proliferation upon addition of bacteria-derived superantigen. These results suggest that KS tumor cells behave differently in their response to cytokines compared with endothelial cells and may be able to evade the local immune response by not expressing costimulatory molecules necessary for T cell proliferation.


Assuntos
Ativação Linfocitária , Sarcoma de Kaposi/imunologia , Linfócitos T/imunologia , Antígenos de Bactérias/imunologia , Antígenos CD/análise , Antígeno B7-1/análise , Antígeno B7-2 , Endotélio Vascular/imunologia , Endotélio Vascular/metabolismo , Humanos , Glicoproteínas de Membrana/análise , Sarcoma de Kaposi/metabolismo , Neoplasias Cutâneas/imunologia , Staphylococcus aureus/imunologia , Superantígenos/imunologia , Células Tumorais Cultivadas
17.
J Neurosci ; 16(1): 19-30, 1996 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-8613785

RESUMO

NMDA receptor antagonists can induce a schizophrenia-like psychosis, but the role of NMDA receptors in the pathophysiology of schizophrenia remains unclear. Expression patterns of mRNAs for five NMDA receptor subunits (NR1/NR2A-D) were determined by in situ hybridization in prefrontal, parieto-temporal, and cerebellar cortex of brains from schizophrenics and from neuroleptic-treated and nonmedicated controls. In the cerebral cortex of both schizophrenics and controls, mRNAs for NR1, NR2A, NR2B, and NR2D subunits were preferentially expressed in layers II/III, Va, and VIa, with much higher levels in the prefrontal than in the parieto-temporal cortex. Levels of mRNA for the NR2C subunit were very low overall. By contrast, the cerebellar cortex of both schizophrenics and controls contained very high levels of NR2C subunit mRNA, whereas levels for the other subunit mRNAs were very low, except NR1, for which levels were moderate. Significant alterations in the schizophrenic cohort were confined to the prefrontal cortex. Here there was a shift in the relative proportions of mRNAs for the NR2 subunit family, with a 53% relative increase in expression of the NR2D subunit mRNA. No comparable changes were found in neuroleptic-treated or untreated controls. These findings indicate regional heterogeneity of NMDA receptor subunit expression in human cerebral and cerebellar cortex. In schizophrenics, the alterations in expression of NR2 subunit mRNA in prefrontal cortex are potential indicators of deficits in NMDA receptor-mediated neurotransmission accompanying functional hypoactivity of the frontal lobes.


Assuntos
Córtex Pré-Frontal/fisiopatologia , Receptores de N-Metil-D-Aspartato/genética , Esquizofrenia/genética , Autorradiografia , Cerebelo/fisiopatologia , Cerebelo/ultraestrutura , Feminino , Expressão Gênica/fisiologia , Humanos , Hibridização In Situ , Masculino , Pessoa de Meia-Idade , Lobo Parietal/fisiopatologia , Lobo Parietal/ultraestrutura , Córtex Pré-Frontal/ultraestrutura , RNA Mensageiro/análise , Receptores de N-Metil-D-Aspartato/ultraestrutura , Esquizofrenia/fisiopatologia , Lobo Temporal/fisiopatologia , Lobo Temporal/ultraestrutura
19.
Invasion Metastasis ; 15(5-6): 189-96, 1995.
Artigo em Inglês | MEDLINE | ID: mdl-8765193

RESUMO

Human neonatal foreskin was maintained in organ culture under serum-free, growth-factor-free conditions or in the presence of a combination of growth factors that are known to stimulate keratinocyte proliferation in monolayer culture. Previously, we have shown that normal histology is maintained when growth-factor-free conditions are used but that the epithelium undergoes a hyperproliferative response and invades the dermis in the presence of the exogenous growth factors. In the present study, the tissue was examined by immunofluorescence for expression of alpha 6 and beta 4 integrin components and for E-cadherin. Under growth factor-free conditions, both alpha 6 and beta 4 were localized to the basal surface of epithelial cells in contact with the basement membrane. In contrast, both epitopes were diffusely distributed throughout the basal epithelium in the presence of growth factors. E-cadherin expression was rapidly lost from the tissue in organ culture. This occurred in both the presence and absence of exogenous growth factors. On the basis of these immunochemical results, we conclude that the same changes in alpha 6 and beta 4 expression that are seen in rapidly proliferating keratinocytes and squamous epithelial cell tumors can be seen in the epidermis of organ-cultured skin when it is maintained in the presence of epithelial growth factors. The observed loss of E-cadherin, in contrast, appears to be a consequence of incubation in organ culture.


Assuntos
Moléculas de Adesão Celular/biossíntese , Expressão Gênica , Pele/metabolismo , Antígenos CD/biossíntese , Caderinas/biossíntese , Divisão Celular , Membrana Celular/fisiologia , Meios de Cultivo Condicionados , Células Epiteliais , Epitélio/efeitos dos fármacos , Epitélio/metabolismo , Substâncias de Crescimento/farmacologia , Humanos , Recém-Nascido , Integrina alfa6 , Integrina beta4 , Queratinócitos/citologia , Masculino , Técnicas de Cultura de Órgãos , Pele/citologia
20.
Gastroenterol Clin Biol ; 17(4): 259-63, 1993.
Artigo em Francês | MEDLINE | ID: mdl-8339884

RESUMO

Radiation hazards to operators performing retrograde endoscopic cholangio-pancreatographies (RECP) have been investigated. The principles and central elements of French medical radioprotection legislation are recalled. Doses received by the operators, over a one month period representative of their usual work, were measured in two ways: by using a ionisation chamber and with thermoluminescent detectors worn by the staff. Extrapolated to 12 months, the results were inferior to the annual reglementary dose limit: whole body < 1.2 mSv (against 50 mSv), eye lens = 38.4 mSv (against 150 mSv). Further means for reducing dose levels are proposed.


Assuntos
Colangiopancreatografia Retrógrada Endoscópica/efeitos adversos , Lesões por Radiação/prevenção & controle , Proteção Radiológica , Humanos , Recursos Humanos em Hospital , Doses de Radiação , Lesões por Radiação/etiologia
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