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1.
Morphologie ; 106(355): 252-259, 2022 Dec.
Article in English | MEDLINE | ID: mdl-34924282

ABSTRACT

The anti-Müllerian hormone (AMH) is a heterodimeric glycoprotein belonging to the TGFb superfamily implicated in human embryonic development. This hormone was first described as allowing regression of the epithelial embryonic Müllerian structures in males, which would otherwise differentiate into the uterus and fallopian tubes. It activates a signaling pathway mediated by two transmembrane receptors. Binding of AMH to its receptor induces morphological changes leading to the degeneration of Müllerian ducts. Recently, new data has shown the role played by this hormone on structures other than the genital tract. If testicular AMH expression decreases in humans over the course of a lifetime, synthesis may persist in other tissues in adulthood. The mechanisms underlying its production have been unveiled. The aim of this review is to describe the different pathways in which AMH has been identified and plays a pivotal role.


Subject(s)
Anti-Mullerian Hormone , Mullerian Ducts , Male , Female , Humans , Adult , Anti-Mullerian Hormone/metabolism , Mullerian Ducts/metabolism , Glycoproteins/metabolism , Testis/metabolism , Signal Transduction/physiology
2.
Res Involv Engagem ; 3: 28, 2017.
Article in English | MEDLINE | ID: mdl-29225922

ABSTRACT

PLAIN ENGLISH SUMMARY: It is important for health care workers to know the needs and expectations of their patients. Therefore, service users have to be involved in research. To achieve a meaningful dialogue between service users, healthcare workers and researchers, participatory methods are needed. This paper describes how the application of a specific participatory methodology, Participatory Learning and Action (PLA) can lead to such a meaningful dialogue. In PLA all stakeholders are regarded as equal partners and collaborators in research.During 2011-2015, a European project called RESTORE used PLA in Austria, Greece, Ireland, The Netherlands and the UK to investigate how communication between primary health care workers and their migrant patients could be improved.Seventy eight migrants, interpreters, doctors, nurses and other key stakeholders (see Table 2) participated in 62 PLA sessions. These dialogues (involving discussions, activities, PLA techniques and evaluations) were generally 2-3 h long and were recorded and analysed by the researchers.Participants reported many positive experiences about their dialogues with other stakeholders. There was a positive, trusting atmosphere in which all stakeholders could express their views despite differences in social power. This made for better understanding within and across stakeholder groups. For instance a doctor changed her view on the use of interpreters after a migrant explained why this was important. Negative experiences were rare: some doctors and healthcare workers thought the PLA sessions took a lot of time; and despite the good dialogue, there was disappointment that very few migrants used the new interpreting service. ABSTRACT: Background In order to be effective, primary healthcare must understand the health needs, values and expectations of the population it serves. Recent research has shown that the involvement of service users and other stakeholders and gathering information on their perspectives can contribute positively to many aspects of primary healthcare. Participatory methodologies have the potential to support engagement and dialogue between stakeholders from academic, migrant community and health service settings. This paper focuses on a specific participatory research methodology, Participatory Learning and Action (PLA) in which all stakeholders are regarded as equal partners and collaborators in research.Our research question for this paper was: "Does the application of PLA lead to meaningful engagement of all stakeholders, and if so, what elements contribute to a positive and productive inter-stakeholder dialogue?". Methods We explored the use of PLA in RESTORE, a European FP7-funded project, during 2011-2015 in 5 countries: Austria, Greece, Ireland, the Netherlands and the UK. The objective of RESTORE was to investigate and support the implementation of guidelines and training initiatives (G/TIs) to enhance communication in cross-cultural primary care consultations with migrants.Seventy eight stakeholders (migrants, interpreters, doctors, nurses and others - see Table 2) participated in a total of 62 PLA sessions (discussions, activities, evaluations) of approximately 2-3 h' duration across the five sites. During the fieldwork, qualitative data were generated about stakeholders' experiences of engagement in this dialogue, by means of various methods including participatory evaluations, researchers' fieldwork reports and researcher interviews. These were analysed following the principles of thematic analysis. Results Stakeholders involved in PLA inter-stakeholder dialogues reported a wide range of positive experiences of engagement, and very few negative experiences. A positive atmosphere during early research sessions helped to create a sense of safety and trust. This enabled stakeholders from very different backgrounds, with different social status and power, to offer their perspectives in a way that led to enhanced learning in the group - they learned with and from each other. This fostered shifts in understanding - for example, a doctor changed her view on interpreted consultations because of the input of the migrant service-users. Conclusion PLA successfully promoted stakeholder involvement in meaningful and productive inter-stakeholder dialogues. This makes it an attractive approach to enhance the further development of health research partnerships to advance primary healthcare.

3.
Int J Equity Health ; 16(1): 32, 2017 02 10.
Article in English | MEDLINE | ID: mdl-28222736

ABSTRACT

BACKGROUND: Cross-cultural communication in primary care is often difficult, leading to unsatisfactory, substandard care. Supportive evidence-based guidelines and training initiatives (G/TIs) exist to enhance cross cultural communication but their use in practice is sporadic. The objective of this paper is to elucidate how migrants and other stakeholders can adapt, introduce and evaluate such G/TIs in daily clinical practice. METHODS: We undertook linked qualitative case studies to implement G/TIs focused on enhancing cross cultural communication in primary care, in five European countries. We combined Normalisation Process Theory (NPT) as an analytical framework, with Participatory Learning and Action (PLA) as the research method to engage migrants, primary healthcare providers and other stakeholders. Across all five sites, 66 stakeholders participated in 62 PLA-style focus groups over a 19 month period, and took part in activities to adapt, introduce, and evaluate the G/TIs. Data, including transcripts of group meetings and researchers' fieldwork reports, were coded and thematically analysed by each team using NPT. RESULTS: In all settings, engaging migrants and other stakeholders was challenging but feasible. Stakeholders made significant adaptations to the G/TIs to fit their local context, for example, changing the focus of a G/TI from palliative care to mental health; or altering the target audience from General Practitioners (GPs) to the wider multidisciplinary team. They also progressed plans to deliver them in routine practice, for example liaising with GP practices regarding timing and location of training sessions and to evaluate their impact. All stakeholders reported benefits of the implemented G/TIs in daily practice. Training primary care teams (clinicians and administrators) resulted in a more tolerant attitude and more effective communication, with better focus on migrants' needs. Implementation of interpreter services was difficult mainly because of financial and other resource constraints. However, when used, migrants were more likely to trust the GP's diagnoses and GPs reported a clearer understanding of migrants' symptoms. CONCLUSIONS: Migrants, primary care providers and other key stakeholders can work effectively together to adapt and implement G/TIs to improve communication in cross-cultural consultations, and enhance understanding and trust between GPs and migrant patients.


Subject(s)
Communication , Cultural Competency/education , Emigrants and Immigrants , Health Personnel/education , Practice Guidelines as Topic , Primary Health Care , Transients and Migrants , Communication Barriers , Education , Europe , Female , Focus Groups , Guideline Adherence , Humans , Male , Problem-Based Learning , Qualitative Research , Referral and Consultation
4.
Cancer Radiother ; 17(2): 136-9, 2013 Apr.
Article in French | MEDLINE | ID: mdl-23538040

ABSTRACT

Cutaneous basal or squamous cell carcinomas are frequent lesions, their prognosis being associated to local control. Surgery remains the standard of treatment, if a complete resection can be realized without impairment of cosmesis or function. Brachytherapy can be used in the other cases, and is especially well adapted to periorificial lesions of the face. It is mostly realized with low dose rate iridium wires, but can be done with high dose rate if outpatient treatment is preferred. It allows high local control rates with very few late complications. The indication has to be discussed as first line treatment, according to the patient's age and general condition, the characteristics of the lesion, and the risk of late cosmetic or functional side-effects of the different therapeutic options.


Subject(s)
Brachytherapy/methods , Carcinoma, Basal Cell/radiotherapy , Carcinoma, Squamous Cell/radiotherapy , Lip Neoplasms/radiotherapy , Skin Neoplasms/radiotherapy , Brachytherapy/adverse effects , Esthetics , Female , Humans , Iridium Radioisotopes/therapeutic use , Lymphatic Metastasis , Male , Radiometry , Radiopharmaceuticals/therapeutic use , Radiotherapy Dosage , Radiotherapy Planning, Computer-Assisted , Radiotherapy, Image-Guided , Treatment Outcome
5.
Cancer Radiother ; 17(2): 151-4, 2013 Apr.
Article in French | MEDLINE | ID: mdl-23402876

ABSTRACT

The standard of care of local treatment for extremities soft tissue sarcomas relies on conservative surgery combined with external beam radiotherapy. Brachytherapy can be realized instead of external beam radiotherapy in selected cases, or more often used as a boost dose on a limited volume on the area at major risk of relapse, especially if a microscopic positive resection is expected. In these cases, this combination allows to obtain the best local control rates published. Close interaction and communication between radiation oncologist and surgeon are mandatory at the time of implantation to limit the risk of side effects. Long-term results are available for low-dose rate brachytherapy. Nowadays, pulsed dose rate is more often used. More limited experience has been reported for high dose rate.


Subject(s)
Brachytherapy/methods , Sarcoma/radiotherapy , Aftercare , Brachytherapy/adverse effects , Brachytherapy/instrumentation , Cicatrix/etiology , Combined Modality Therapy , Extremities , Humans , Imaging, Three-Dimensional , Radiation Injuries/etiology , Radiometry , Radiopharmaceuticals/administration & dosage , Radiopharmaceuticals/therapeutic use , Radiotherapy Dosage , Radiotherapy Planning, Computer-Assisted , Randomized Controlled Trials as Topic , Sarcoma/surgery , Treatment Outcome
6.
Phys Med Biol ; 57(8): 2189-207, 2012 Apr 21.
Article in English | MEDLINE | ID: mdl-22456322

ABSTRACT

The energy and specific energy absorbed in the main cell compartments (nucleus and cytoplasm) in typical radiobiology experiments are usually estimated by calculations as they are not accessible for a direct measurement. In most of the work, the cell geometry is modelled using the combination of simple mathematical volumes. We propose a method based on high resolution confocal imaging and ion beam analysis (IBA) in order to import realistic cell nuclei geometries in Monte-Carlo simulations and thus take into account the variety of different geometries encountered in a typical cell population. Seventy-six cell nuclei have been imaged using confocal microscopy and their chemical composition has been measured using IBA. A cellular phantom was created from these data using the ImageJ image analysis software and imported in the Geant4 Monte-Carlo simulation toolkit. Total energy and specific energy distributions in the 76 cell nuclei have been calculated for two types of irradiation protocols: a 3 MeV alpha particle microbeam used for targeted irradiation and a ²³9Pu alpha source used for large angle random irradiation. Qualitative images of the energy deposited along the particle tracks have been produced and show good agreement with images of DNA double strand break signalling proteins obtained experimentally. The methodology presented in this paper provides microdosimetric quantities calculated from realistic cellular volumes. It is based on open-source oriented software that is publicly available.


Subject(s)
Alpha Particles , Keratinocytes/cytology , Keratinocytes/radiation effects , Monte Carlo Method , Absorption , Cell Line , Cell Nucleus/radiation effects , Humans , Phantoms, Imaging
7.
Diabetologia ; 53(2): 331-40, 2010 Feb.
Article in English | MEDLINE | ID: mdl-19908022

ABSTRACT

AIMS/HYPOTHESIS: Pancreatic beta cells chronically exposed to fatty acids may lose specific functions and even undergo apoptosis. Generally, lipotoxicity is triggered by saturated fatty acids, whereas unsaturated fatty acids induce lipodysfunction, the latter being characterised by elevated basal insulin release and impaired glucose responses. The peroxisome proliferator-activated receptor alpha (PPARalpha) has been proposed to play a protective role in this process, although the cellular mechanisms involved are unclear. METHODS: We modulated PPARalpha production in INS-1E beta cells and investigated key metabolic pathways and genes responsible for metabolism-secretion coupling during a culture period of 3 days in the presence of 0.4 mmol/l oleate. RESULTS: In INS-1E cells, the secretory dysfunction primarily induced by oleate was aggravated by silencing of PPARalpha. Conversely, PPARalpha upregulation preserved glucose-stimulated insulin secretion, essentially by increasing the response at a stimulatory concentration of glucose (15 mmol/l), a protection we also observed in human islets. The protective effect was associated with restored glucose oxidation rate and upregulation of the anaplerotic enzyme pyruvate carboxylase. PPARalpha overproduction increased both beta-oxidation and fatty acid storage in the form of neutral triacylglycerol, revealing overall induction of lipid metabolism. These observations were substantiated by expression levels of associated genes. CONCLUSIONS/INTERPRETATION: PPARalpha protected INS-1E beta cells from oleate-induced dysfunction, promoting both preservation of glucose metabolic pathways and fatty acid turnover.


Subject(s)
Carbohydrates/physiology , Insulin-Secreting Cells/physiology , Oleic Acid/toxicity , PPAR alpha/physiology , Adenosine Triphosphate/metabolism , Apoptosis/drug effects , CD36 Antigens/genetics , Carnitine O-Palmitoyltransferase/genetics , Cell Culture Techniques , Fatty Acids, Nonesterified/pharmacology , Gene Expression Regulation , Glucose/pharmacology , Humans , Insulin/metabolism , Insulin Secretion , Insulin-Secreting Cells/cytology , Insulin-Secreting Cells/drug effects , Insulin-Secreting Cells/pathology , PPAR alpha/pharmacology , Reverse Transcriptase Polymerase Chain Reaction , Tubulin/genetics
8.
Oncogene ; 26(29): 4261-71, 2007 Jun 21.
Article in English | MEDLINE | ID: mdl-17260022

ABSTRACT

The paired/homeodomain transcription factor Pax4 is essential for islet beta-cell generation during pancreas development and their survival in adulthood. High Pax4 expression was reported in human insulinomas indicating that deregulation of the gene may be associated with tumorigenesis. We report that rat insulinoma INS-1E cells express 25-fold higher Pax4 mRNA levels than rat islets. In contrast to primary beta-cells, activin A but not betacellulin or glucose induced Pax4 mRNA levels indicating dissociation of Pax4 expression from insulinoma cell proliferation. Short hairpin RNA adenoviral constructs targeted to the paired domain or homeodomain (viPax4PD and viPax4HD) were generated. Pax4 mRNA levels were lowered by 73 and 50% in cells expressing either viPax4PD or viPax4HD. Transcript levels of the Pax4 target gene bcl-xl were reduced by 53 and 47%, whereas Pax6 and Pdx1 mRNA levels were unchanged. viPax4PD-infected cells displayed a twofold increase in spontaneous apoptosis and were more susceptible to cytokine-induced cell death. In contrast, proliferation was unaltered. RNA interference-mediated repression of insulin had no adverse effects on either Pax4 or Pdx1 expression as well as on cell replication or apoptosis. These results indicate that Pax4 is redundant for proliferation of insulinoma cells, whereas it is essential for survival through upregulation of the antiapoptotic gene bcl-xl.


Subject(s)
Homeodomain Proteins/genetics , Insulinoma/genetics , Insulinoma/pathology , Paired Box Transcription Factors/genetics , Animals , Apoptosis/genetics , Apoptosis Regulatory Proteins/genetics , Apoptosis Regulatory Proteins/physiology , Cell Division/genetics , Cell Line, Tumor , Cell Proliferation , Cell Survival/genetics , Homeodomain Proteins/physiology , Insulinoma/metabolism , Paired Box Transcription Factors/physiology , RNA, Messenger/biosynthesis , Rats , Rats, Wistar , Up-Regulation/genetics , bcl-X Protein/biosynthesis , bcl-X Protein/genetics
9.
Diabetologia ; 50(2): 348-58, 2007 Feb.
Article in English | MEDLINE | ID: mdl-17149590

ABSTRACT

AIMS/HYPOTHESIS: Effects of the transcription factor v-maf musculoaponeurotic fibrosarcoma oncogene homologue A (MAFA) on the regulation of beta cell gene expression and function were investigated. MATERIALS AND METHODS: INS-1 stable cell lines permitting inducible up- or downregulation of this transcription factor were established. RESULTS: MAFA overproduction enhanced and its dominant-negative mutant (DN-MAFA) diminished binding of the factor to the insulin promoter, correlating with insulin mRNA levels and cellular protein content. Glucose-stimulated insulin secretion was facilitated by MAFA and blunted by DN-MAFA. This is partly due to alterations in glucokinase production, the glucose sensor of beta cells. In addition, the expression of important beta cell genes, e.g. those encoding solute carrier family 2 (facilitated glucose transporter), member 2 (formerly known as GLUT2), pancreatic and duodenal homeobox factor 1 (PDX1), NK6 transcription factor-related, locus 1 (NKX6-1), glucagon-like peptide 1 receptor (GLP1R), prohormone convertase 1/3 (PCSK1) and pyruvate carboxylase (PC), was regulated positively by MAFA and negatively by DN-MAFA. CONCLUSIONS/INTERPRETATION: The data suggest that MAFA is not only a key activator of insulin transcription, but also a master regulator of genes implicated in maintaining beta cell function, in particular metabolism-secretion coupling, proinsulin processing and GLP1R signalling. Our in vitro study provides molecular targets that explain the phenotype of recently reported Mafa-null mice. We also demonstrate that MAFA is produced specifically in beta cells of human islets. Glucose influenced DNA-binding activity of MAFA in rat islets in a bell-shaped manner. MAFA thus qualifies as a master regulator of beta-cell-specific gene expression and function.


Subject(s)
Insulin-Secreting Cells/physiology , Insulin/genetics , Lectins, C-Type/physiology , Membrane Glycoproteins/physiology , Animals , Cell Line, Tumor , Gene Expression Regulation , Humans , Insulin/biosynthesis , Insulin/metabolism , Insulin Secretion , Insulin-Secreting Cells/metabolism , Insulinoma , Lectins, C-Type/deficiency , Lectins, C-Type/genetics , Membrane Glycoproteins/deficiency , Membrane Glycoproteins/genetics , Mice , Mice, Knockout , Pancreatic Neoplasms , Rats , Transcription, Genetic
10.
Diabetologia ; 48(5): 900-5, 2005 May.
Article in English | MEDLINE | ID: mdl-15834548

ABSTRACT

AIMS/HYPOTHESIS: Loss of pancreatic beta cells is the crucial event in the development of type 1 diabetes. It is the result of an imbalance between autoimmune destruction and insufficient regeneration of islet cells. To study the role of islet cell regeneration in the pathogenesis of type 1 diabetes, we focused on PAX4, a paired homeodomain transcriptional repressor that is involved in islet cell growth. METHODS: The study included 379 diabetic children and 1,070 controls from two distinct populations, and a cohort of children who had not developed type 1 diabetes, despite the presence of islet cell antibodies. Genomic DNA analysis of PAX4 was carried out via direct sequencing of PCR-amplified fragments and allelic discrimination. We compared the transrepression potential of the PAX4 variants in betaTC3 cells and analysed their influence on beta cell growth. RESULTS: The type 1 diabetic subjects are different from the normal individuals in terms of the genotype distribution of the A1168C single nucleotide polymorphism in PAX4. The C/C genotype is frequent among type 1 diabetic children (73%) and rare among the control population (32%). Conversely, the A/C genotype is prevalent among control subjects (62%) and antibody-positive children without type 1 diabetes (73.6%), but uncommon among subjects with type 1 diabetes (17.5%). The combination of PAX4A and PAX4C is functionally more active than PAX4C alone (the "diabetic" variant). Beta cells expressing PAX4A and PAX4C efficiently proliferate when stimulated with glucose, whereas cells expressing the PAX4C variant alone do not. CONCLUSIONS/INTERPRETATION: We have identified a link between beta cell regenerative capacity and susceptibility to type 1 diabetes. This finding could explain the fact that not all of the individuals who develop autoimmunity against beta cells actually contract the disease. The C/C genotype of the A1168C polymorphism in PAX4 can be viewed as a predisposition marker that can help to detect individuals prone to develop type 1 diabetes.


Subject(s)
Diabetes Mellitus, Type 1/genetics , Genetic Variation , Homeodomain Proteins/genetics , Polymorphism, Single Nucleotide , Transcription Factors/genetics , Amino Acid Substitution , Animals , Binding Sites , Blood Glucose/metabolism , Child , DNA/blood , DNA/genetics , DNA/isolation & purification , Diabetes Mellitus, Type 1/blood , Female , Gene Frequency , Genetic Markers , Homeodomain Proteins/metabolism , Humans , Insulin/genetics , Male , Mutation, Missense , Paired Box Transcription Factors , Promoter Regions, Genetic , Reference Values , Switzerland , Transcription Factors/metabolism
11.
Phys Rev Lett ; 91(20): 209801; author reply 209802, 2003 Nov 14.
Article in English | MEDLINE | ID: mdl-14683411
12.
Diabetologia ; 46(6): 810-21, 2003 Jun.
Article in English | MEDLINE | ID: mdl-12783165

ABSTRACT

AIMS/HYPOTHESIS: The transcription factor Pdx1 is required for the development and differentiation of all pancreatic cells. Beta-cell specific inactivation of Pdx1 in developing or adult mice leads to an increase in glucagon-expressing cells, suggesting that absence of Pdx1could favour glucagon gene expression by a default mechanism. METHOD: We investigated the inhibitory role of Pdx1 on glucagon gene expression in vitro. The glucagonoma cell line InR1G9 was transduced with a Pdx1-encoding lentiviral vector and insulin and glucagon mRNA levels were analysed by northern blot and real-time PCR. To understand the mechanism by which Pdx1 inhibits glucagon gene expression, we studied its effect on glucagon promoter activity in non-islet cells using transient transfections and gel-shift analysis. RESULTS: In glucagonoma cells transduced with a Pdx1-encoding lentiviral vector, insulin gene expression was induced while glucagon mRNA levels were reduced by 50 to 60%. In the heterologous cell line BHK-21, Pdx1 inhibited by 60 to 80% the activation of the alpha-cell specific element G1 conferred by Pax-6 and/or Cdx-2/3. Although Pdx1 could bind three AT-rich motifs within G1, two of which are binding sites for Pax-6 and Cdx-2/3, the affinity of Pdx1 for G1 was much lower as compared to Pax-6. In addition, Pdx1 inhibited Pax-6 mediated activation through G3, to which Pdx1 was unable to bind. Moreover, a mutation impairing DNA binding of Pdx1 had no effect on its inhibition on Cdx-2/3. Since Pdx1 interacts directly with Pax-6 and Cdx-2/3 forming heterodimers, we suggest that Pdx1 inhibits glucagon gene transcription through protein to protein interactions with Pax-6 and Cdx-2/3. CONCLUSION/INTERPRETATION: Cell-specific expression of the glucagon gene can only occur when Pdx1 expression extinguishes from the early alpha cell precursor.


Subject(s)
Glucagon/genetics , Trans-Activators/genetics , Transcription, Genetic/genetics , Animals , Base Sequence , Binding Sites , Cell Line , Cricetinae , Genetic Vectors , Homeodomain Proteins/genetics , Homeodomain Proteins/metabolism , Humans , Insulin/genetics , Islets of Langerhans/physiology , Mesocricetus , Molecular Sequence Data , Oligodeoxyribonucleotides , Organ Specificity , Trans-Activators/metabolism , Transfection
13.
Gene ; 279(2): 109-17, 2001 Nov 28.
Article in English | MEDLINE | ID: mdl-11733135

ABSTRACT

Proximal spinal muscular atrophy (SMA) is an autosomal recessive disease characterized by degeneration of alpha-motor neurons and muscular atrophy. The causal survival motor neuron (SMN) gene maps to a complex region of chromosome 5q13 harbouring an inverted duplication. Thus, there are two SMN genes, SMN1 and SMN2, but SMN1-deficiency alone causes SMA. In this study we demonstrate, for the first time, down-regulation of SMN promoter activity during cellular differentiation. Specifically, the minimal SMN promoter is four times more active in undifferentiated embryonal carcinoma P19 cells compared to cells treated with retinoic acid (RA) to initiate neuronal differentiation. This effect is mediated by sequences contained within the minimal core promoter that we have confined to the 257 nucleotides upstream of exon 1. We have identified seven regions that are highly conserved between the mouse and human SMN core promoters and this region contains the consensus sequence for a number of transcription factors. Most notably, AhR, HNF-3 and N-Oct3 have already been shown to respond to RA treatment of EC cells, while E47, HNF-3, MAZ, N-Oct3 and Pit-1a have been implicated in embryonic, muscle or neural development. In addition, we have mapped two strong transcription initiation sites upstream of SMN exon 1. The novel -79 site identified in this study is preferentially utilized during human foetal development. Furthermore, analysis of RNA from SMA patients with deletions of the entire SMN1 gene or chimpanzees that lack SMN2 suggests that the level of transcription initiation at these sites may be different for the SMN1 and SMN2 genes. Taken together, this work provides the first demonstration of transcriptional regulation of these genes during cellular differentiation and development. Deciphering the underlying mechanisms responsible for regulating SMN transcription may provide important clues towards enhancing SMN2 gene expression, one target for the treatment of SMA.


Subject(s)
Cell Differentiation/genetics , Nerve Tissue Proteins/genetics , Animals , Base Sequence , Binding Sites/genetics , Chloramphenicol O-Acetyltransferase/genetics , Chloramphenicol O-Acetyltransferase/metabolism , Cyclic AMP Response Element-Binding Protein , DNA/genetics , Female , Gene Expression Regulation/drug effects , Humans , Mice , Molecular Sequence Data , Muscular Atrophy, Spinal/genetics , Promoter Regions, Genetic/genetics , RNA-Binding Proteins , Recombinant Fusion Proteins/drug effects , Recombinant Fusion Proteins/genetics , Recombinant Fusion Proteins/metabolism , SMN Complex Proteins , Sequence Homology, Nucleic Acid , Survival of Motor Neuron 1 Protein , Survival of Motor Neuron 2 Protein , Transcription Factors/metabolism , Transcription Initiation Site , Transcription, Genetic , Tretinoin/pharmacology , Tumor Cells, Cultured
14.
Phys Rev Lett ; 84(25): 5908-11, 2000 Jun 19.
Article in English | MEDLINE | ID: mdl-10991085

ABSTRACT

Methods for distilling Greenberger-Horne-Zeilinger (GHZ) states from arbitrary entangled tripartite pure states are described. These techniques work for virtually any input state. Each technique has two stages which we call primary and secondary distillations. Primary distillation produces a GHZ state with some probability, so that when applied to an ensemble of systems a certain percentage is discarded. Secondary distillation produces further GHZs from the discarded systems. These protocols are developed with the help of an approach to quantum information theory based on absolutely selective information, which has other potential applications.


Subject(s)
Information Theory , Quantum Theory
15.
J Nucl Med ; 41(8): 1369-79, 2000 Aug.
Article in English | MEDLINE | ID: mdl-10945530

ABSTRACT

UNLABELLED: The availability of accurately aligned, whole-body anatomical (CT) and functional (PET) images could have a significant impact on diagnosing and staging malignant disease and on identifying and localizing metastases. Computer algorithms to align CT and PET images acquired on different scanners are generally successful for the brain, whereas image alignment in other regions of the body is more problematic. METHODS: A combined PET/CT tomograph with the unique capability of acquiring accurately aligned functional and anatomical images for any part of the human body has been designed and built. The PET/CT scanner was developed as a combination of a Siemens Somatom AR.SP spiral CT and a partial-ring, rotating ECAT ART PET scanner. All components are mounted on a common rotational support within a single gantry. The PET and CT components can be operated either separately, or in combined mode. In combined mode, the CT images are used to correct the PET data for scatter and attenuation. Fully quantitative whole-body images are obtained for an axial extent of 100 cm in an imaging time of less than 1 h. When operated in PET mode alone, transmission scans are acquired with dual 137Cs sources. RESULTS: The scanner is fully operational and the combined device has been operated successfully in a clinical environment. Over 110 patients have been imaged, covering a range of different cancers, including lung, esophageal, head and neck, melanoma, lymphoma, pancreas, and renal cell. The aligned PET and CT images are used both for diagnosing and staging disease and for evaluating response to therapy. We report the first performance measurements from the scanner and present some illustrative clinical studies acquired in cancer patients. CONCLUSION: A combined PET and CT scanner is a practical and effective approach to acquiring co-registered anatomical and functional images in a single scanning session.


Subject(s)
Neoplasms/diagnostic imaging , Tomography, Emission-Computed/instrumentation , Tomography, X-Ray Computed/instrumentation , Adult , Aged , Carcinoma, Squamous Cell/diagnostic imaging , Carcinoma, Squamous Cell/pathology , Data Interpretation, Statistical , Duodenal Neoplasms/diagnostic imaging , Equipment Design , Female , Fluorodeoxyglucose F18 , Humans , Lung Neoplasms/diagnostic imaging , Lung Neoplasms/pathology , Male , Neoplasm Metastasis , Pancreatic Neoplasms/diagnostic imaging , Polyps/diagnostic imaging , Radiopharmaceuticals , Tomography, Emission-Computed/methods , Tomography, X-Ray Computed/methods
17.
Article in English | MEDLINE | ID: mdl-11969622

ABSTRACT

We consider a number of proposals for the entropy of sets of classical coarse-grained histories based on the procedures of Jaynes, and we prove a series of inequalities relating these measures. We then examine these as a function of the coarse-graining for various classical systems, and show explicitly that the entropy is minimized by the finest-grained description of a set of histories. We propose an extension of the second law of thermodynamics to the entropy of histories. We briefly discuss the implications for decoherent or consistent history formulations of quantum mechanics.

19.
Endocrinology ; 139(9): 3704-11, 1998 Sep.
Article in English | MEDLINE | ID: mdl-9724021

ABSTRACT

High fat feeding reportedly enhances hypothalamus-pituitary-adrenal (HPA) responses to stress in adult rats. The present study tested whether elevated fat intake during suckling could have short and/or long lasting consequences on HPA regulation in the offspring. Mothers were fed either a control (C; 5% fat) or high fat (HF; 20% fat) diet during the last week of gestation and throughout lactation. After weaning (day 21), pups from C and HF mothers were fed a chow diet. Offspring from both C- and HF-fed mothers were tested for ACTH and corticosterone responses to stress on postnatal days 10 and 35. We found that HF feeding produced higher lipid levels in the milk of HF compared with C lactating rat dams and that offspring of these mothers had significantly increased retroperitoneal fat pad weight and relative adipose mass on day 21 as well as elevated plasma leptin levels on days 10 and 21 of age. After weaning, pups from the HF mothers had lower plasma leptin levels than those from C mothers. Maternal dietary fat affected HPA responsiveness in the offspring in an age-related manner. Neonatal pups (day 10) from the HF mothers exhibited a reduction in the ACTH and corticosterone responses to ether stress. However, in 35-day-old offspring from HF-fed dams, stress-induced ACTH secretion was increased compared with that in pups from the C-fed mothers. These results demonstrate that maternal diet and increased fat intake through the milk are important regulators of HPA responsiveness in neonates and prepubertal rats. During neonatal life, the blunted stress responsiveness seen with elevated fat intake and the resulting high leptin levels might protect the pups from excessive HPA activation. After removal of the maternal dietary influence and reduced leptin levels, enhanced ACTH stress responses are observed as in adult rats fed a HF diet. Because of the inverse relationship between plasma levels of leptin and HPA responses in pups, the possibility exists that the effects of the HF diet on stress responsiveness are mediated by changes in leptin exposure during development.


Subject(s)
Aging/physiology , Animals, Newborn/physiology , Dietary Fats/administration & dosage , Hypothalamo-Hypophyseal System/physiopathology , Lactation/physiology , Pituitary-Adrenal System/physiopathology , Stress, Physiological/physiopathology , Adipose Tissue/anatomy & histology , Animals , Animals, Newborn/growth & development , Body Composition/drug effects , Dietary Fats/pharmacology , Female , Leptin , Lipids/analysis , Male , Milk/chemistry , Organ Size/drug effects , Proteins/analysis , Proteins/physiology , Rats , Rats, Sprague-Dawley , Retroperitoneal Space/anatomy & histology
20.
Diabetes ; 47(7): 1086-94, 1998 Jul.
Article in English | MEDLINE | ID: mdl-9648832

ABSTRACT

Chronic exposure of pancreatic beta-cells to high glucose has pleiotropic action on beta-cell function. In particular, it induces key glycolytic genes, promotes glycogen deposition, and causes beta-cell proliferation and altered insulin secretion characterized by sensitization to low glucose. Postglycolytic events, in particular, anaplerosis and lipid signaling, are thought to be implicated in beta-cell activation by glucose. To understand the biochemical nature of the beta-cell adaptive process to hyperglycemia, we studied the regulation by glucose of lipogenic genes in the beta-cell line INS-1. A 3-day exposure of cells to elevated glucose (5-25 mmol/l) increased the enzymatic activities of fatty acid synthase 3-fold, acetyl-CoA carboxylase 30-fold, and malic enzyme 1.3-fold. Pyruvate carboxylase and citrate lyase expression remained constant. Similar observations were made at the protein and mRNA levels except for malic enzyme mRNA, which did not vary. Metabolic gene expression changes were associated with chronically elevated levels of citrate, malate, malonyl-CoA, and conversion of glucose carbon into lipids, even in cells that were subsequently exposed to low glucose. Similarly, fatty acid oxidation was suppressed and phospholipid and triglyceride synthesis was enhanced independently of the external glucose concentration in cells preexposed to high glucose. The results suggest that a coordinated induction of glycolytic and lipogenic genes in conjunction with glycogen and triglyceride deposition, as well as increased anaplerosis and altered lipid partitioning, contribute to the adaptive process to hyperglycemia and glucose sensitization of the beta-cell.


Subject(s)
Gene Expression/drug effects , Glucose/pharmacology , Islets of Langerhans/drug effects , Islets of Langerhans/metabolism , Lipids/biosynthesis , Lipids/genetics , Acetyl-CoA Carboxylase/genetics , Acetyl-CoA Carboxylase/metabolism , Animals , Cell Line , Citric Acid Cycle/drug effects , Fatty Acid Synthases/genetics , Fatty Acid Synthases/metabolism , Glucose/administration & dosage , Glycolysis/genetics , Malate Dehydrogenase/genetics , Malate Dehydrogenase/metabolism , Malonyl Coenzyme A/metabolism , RNA, Messenger/metabolism , Rats , Time Factors , Transcription, Genetic/drug effects , Triglycerides/metabolism
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