190 research outputs found

    A proposed mechanism for progesterone regulation of trophoblast MMP2 transcription independent of classical progesterone response elements on its promoter

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    BACKGROUND: Progesterone receptor act as ligand-inducible transcription factor in the respective target cells by binding to specific progesterone response elements in the promoter of the target genes. However, despite the lack of the classical progesterone response elements on matrix-metalloproteinase-2 promoter, progesterone has been shown to decrease the activity of this promoter PRESENTATION OF THE HYPOTHESIS: It has recently been suggested that in addition to interacting with their classical co-activators and co-repressors, progesterone receptor are capable of binding to several transcription factors. By interacting with other classes of transcription factors, progesterone receptor is capable of transcriptional activation through the transcription factors cognate DNA binding site. TESTING THE HYPOTHESIS: Exploring transcription factors and transcription binding sites, interacting with the progesterone receptor in modulation of the matrix-metalloproteinase promoter. IMPLICATIONS OF THE HYPOTHESIS: Identification of additional endogenous progesterone target genes makes it possible to further explore the signaling mechanisms by which the hormone regulates biological actions. Furthermore, the concepts of ligand-driven conformational diversity and selective tissue actions can be exploited in the future for drug development which selectively regulate orphan receptors from the nuclear receptor family

    Stress-Induced Reinstatement of Drug Seeking: 20 Years of Progress

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    In human addicts, drug relapse and craving are often provoked by stress. Since 1995, this clinical scenario has been studied using a rat model of stress-induced reinstatement of drug seeking. Here, we first discuss the generality of stress-induced reinstatement to different drugs of abuse, different stressors, and different behavioral procedures. We also discuss neuropharmacological mechanisms, and brain areas and circuits controlling stress-induced reinstatement of drug seeking. We conclude by discussing results from translational human laboratory studies and clinical trials that were inspired by results from rat studies on stress-induced reinstatement. Our main conclusions are (1) The phenomenon of stress-induced reinstatement, first shown with an intermittent footshock stressor in rats trained to self-administer heroin, generalizes to other abused drugs, including cocaine, methamphetamine, nicotine, and alcohol, and is also observed in the conditioned place preference model in rats and mice. This phenomenon, however, is stressor specific and not all stressors induce reinstatement of drug seeking. (2) Neuropharmacological studies indicate the involvement of corticotropin-releasing factor (CRF), noradrenaline, dopamine, glutamate, kappa/dynorphin, and several other peptide and neurotransmitter systems in stress-induced reinstatement. Neuropharmacology and circuitry studies indicate the involvement of CRF and noradrenaline transmission in bed nucleus of stria terminalis and central amygdala, and dopamine, CRF, kappa/dynorphin, and glutamate transmission in other components of the mesocorticolimbic dopamine system (ventral tegmental area, medial prefrontal cortex, orbitofrontal cortex, and nucleus accumbens). (3) Translational human laboratory studies and a recent clinical trial study show the efficacy of alpha-2 adrenoceptor agonists in decreasing stress-induced drug craving and stress-induced initial heroin lapse

    Hyperglycemia regulates thioredoxin-ROS activity through induction of thioredoxin-interacting protein (TXNIP) in metastatic breast cancer-derived cells MDA-MB-231

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    <p>Abstract</p> <p>Background</p> <p>We studied the RNA expression of the genes in response to glucose from 5 mM (condition of normoglycemia) to 20 mM (condition of hyperglycemia/diabetes) by microarray analysis in breast cancer derived cell line MDA-MB-231. We identified the thioredoxin-interacting protein (TXNIP), whose RNA level increased as a gene product particularly sensitive to the variation of the level of glucose in culture media. We investigated the kinesis of the TXNIP RNA and protein in response to glucose and the relationship between this protein and the related thioredoxin (TRX) in regulating the level of reactive oxygen species (ROS) in MDA-MB-231 cells.</p> <p>Methods</p> <p>MDA-MB-231 cells were grown either in 5 or 20 mM glucose chronically prior to plating. For glucose shift (5/20), cells were plated in 5 mM glucose and shifted to 20 mM at time 0. Cells were analyzed with Affymetrix Human U133A microarray chip and gene expression profile was obtained. Semi-quantitative RT-PCR and Western blot was used to validate the expression of TXNIP RNA and protein in response to glucose, respectively. ROS were detected by CM-H2DCFDA (5–6-chloromethyl-2',7'-dichlorodihydrofluorescein diacetate) and measured for mean fluorescence intensity with flow cytometry. TRX activity was assayed by the insulin disulfide reducing assay.</p> <p>Results</p> <p>We found that the regulation of TXNIP gene expression by glucose in MDA-MB-231 cells occurs rapidly within 6 h of its increased level (20 mM glucose) and persists through the duration of the conditions of hyperglycemia. The increased level of TXNIP RNA is followed by increased level of protein that is associated with increasing levels of ROS and reduced TRX activity. The inhibition of the glucose transporter GLUT1 by phloretin notably reduces TXNIP RNA level and the inhibition of the p38 MAP kinase activity by SB203580 reverses the effects of TXNIP on ROS-TRX activity.</p> <p>Conclusion</p> <p>In this study we show that TXNIP is an oxidative stress responsive gene and its expression is exquisitely regulated by glucose level in highly metastatic MDA-MB-231 cells.</p

    Meier-Gorlin syndrome

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    Meier-Gorlin syndrome (MGS) is a rare autosomal recessive primordial dwarfism disorder, characterized by microtia, patellar applasia/hypoplasia, and a proportionate short stature. Associated clinical features encompass feeding problems, congenital pulmonary emphysema, mammary hypoplasia in females and urogenital anomalies, such as cryptorchidism and hypoplastic labia minora and majora. Typical facial characteristics during childhood comprise a small mouth with full lips and micro-retrognathia. During ageing, a narrow, convex nose becomes more prominent. The diagnosis MGS should be considered in patients with at least two of the three features of the clinical triad of microtia, patellar anomalies, and pre- and postnatal growth retardation. In patients with short stature and/or microtia, the patellae should be assessed with care by ultrasonography before age 6 or radiography thereafter. Mutations in one of five genes (ORC1, ORC4, ORC6, CDT1, and CDC6) of the pre-replication complex, involved in DNA-replication, are detected in approximately 67-78 % of patients with MGS. Patients with ORC1 and ORC4 mutations appear to have the most severe short stature and microcephaly. Management should be directed towards in-depth investigation, treatment and prevention of associated problems, such as growth retardation, feeding problems, hearing loss, luxating patellae, knee pain, gonarthrosis, and possible pulmonary complications due to congenital pulmonary emphysema with or without broncho- or laryngomalacia. Growth hormone treatment is ineffective in most patients with MGS, but may be effective in patients in whom growth continues to decrease after the first year of life (usually growth velocity normalizes after the first year) and with low levels of IGF1. At present, few data is available about reproduction of females with MGS, but the risk of premature labor might be increased. Here, we propose experience-based guidelines for the regular care and treatment of MGS patients

    Psychiatric diagnoses, trauma, and suicidiality

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    BACKGROUND: This study aimed to examine the associations between psychiatric diagnoses, trauma and suicidiality in psychiatric patients at intake. METHODS: During two months, all consecutive patients (n = 139) in a psychiatric hospital in Western Norway were interviewed (response rate 72%). RESULTS: Ninety-one percent had been exposed to at least one trauma; 69 percent had been repeatedly exposed to trauma for longer periods of time. Only 7% acquired a PTSD diagnosis. The comorbidity of PTSD and other psychiatric diagnoses were 78%. A number of diagnoses were associated with specific traumas. Sixty-seven percent of the patients reported suicidal thoughts in the month prior to intake; thirty-one percent had attempted suicide in the preceding week. Suicidal ideation, self-harming behaviour, and suicide attempts were associated with specific traumas. CONCLUSION: Traumatised patients appear to be under- or misdiagnosed which could have an impact on the efficiency of treatment

    VDA, a Method of Choosing a Better Algorithm with Fewer Validations

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    The multitude of bioinformatics algorithms designed for performing a particular computational task presents end-users with the problem of selecting the most appropriate computational tool for analyzing their biological data. The choice of the best available method is often based on expensive experimental validation of the results. We propose an approach to design validation sets for method comparison and performance assessment that are effective in terms of cost and discrimination power

    Differential, Positional-Dependent Transcriptional Response of Antigenic Variation (var) Genes to Biological Stress in Plasmodium falciparum

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    1% of the genes of the human malaria causing agent Plasmodium falciparum belong to the heterogeneous var gene family which encodes P. falciparum erythrocyte membrane protein 1 (PFEMP1). This protein mediates part of the pathogenesis of the disease by causing adherence of infected erythrocytes (IE) to the host endothelium. At any given time, only one copy of the family is expressed on the IE surface. The cues which regulate the allelic exclusion of these genes are not known. We show the existence of a differential expression pattern of these genes upon exposure to biological stress in relation to their positional placement on the chromosome – expression of centrally located var genes is induced while sub-telomeric copies of the family are repressed - this phenomenon orchestrated by the histone deacetylase pfsir2. Moreover, stress was found to cause a switch in the pattern of the expressed var genes thus acting as a regulatory cue. By using pharmacological compounds which putatively affect pfsir2 activity, distinct changes of var gene expression patterns were achieved which may have therapeutic ramifications. As disease severity is partly associated with expression of particular var gene subtypes, manipulation of the IE environment may serve as a mechanism to direct transcription towards less virulent genes

    Posttraumatic stress disorder (PTSD) in children after paediatric intensive care treatment compared to children who survived a major fire disaster

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    <p>Abstract</p> <p>Background</p> <p>The goals were to determine the presence of posttraumatic stress disorder (PTSD) in children after paediatric intensive care treatment, to identify risk factors for PTSD, and to compare this data with data from a major fire disaster in the Netherlands.</p> <p>Methods</p> <p>Children completed the Dutch Children's Responses to Trauma Inventory at three and nine months after discharge from the paediatric intensive care unit (PICU). Comparison data were available from 355 children survivors who completed the same questionnaire 10 months after a major fire disaster.</p> <p>Results</p> <p>Thirty-six children aged eight to 17 years completed questionnaires at three month follow-up, nine month follow-up, or both. More than one third (34.5%) of the children had subclinical PTSD, while 13.8% were likely to meet criteria for PTSD. Maternal PTSD was the strongest predictor for child PTSD. There were no significant differences in (subclinical) PTSD symptoms either over time or compared to symptoms of survivors from the fire disaster.</p> <p>Conclusion</p> <p>This study shows that a considerable number of children have persistent PTSD after PICU treatment. Prevention of PTSD is important to minimize the profound adverse effects that PTSD can have on children's well-being and future development.</p

    Severe traumatic injury during long duration spaceflight: Light years beyond ATLS

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    Traumatic injury strikes unexpectedly among the healthiest members of the human population, and has been an inevitable companion of exploration throughout history. In space flight beyond the Earth's orbit, NASA considers trauma to be the highest level of concern regarding the probable incidence versus impact on mission and health. Because of limited resources, medical care will have to focus on the conditions most likely to occur, as well as those with the most significant impact on the crew and mission. Although the relative risk of disabling injuries is significantly higher than traumatic deaths on earth, either issue would have catastrophic implications during space flight. As a result this review focuses on serious life-threatening injuries during space flight as determined by a NASA consensus conference attended by experts in all aspects of injury and space flight
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