Phuc Nguyen - Academia.edu (original) (raw)

Papers by Phuc Nguyen

PLoS currents, Jan 21, 2010

To evaluate whether cytokines are altered in peripheral blood of rats transgenic for the human Hu... more To evaluate whether cytokines are altered in peripheral blood of rats transgenic for the human Huntington´s disease mutation we investigated serum levels of GRO/KC, IL-1β, IL-13 and TNF-α at a symptomatic stage at 12 months of age. Overall serum levels of these cytokines were not significantly changed between transgenic HD rats and controls. Moreover, we observed a high interindividual variability. Our results indicate that these cytokines will be difficult to pursue as biomarkers in at least this rat model of HD.

Molecular and Cellular Neuroscience, 2008

Huntington's disease (HD) is an age-related neurodegenerative disorder that is currently untreata... more Huntington's disease (HD) is an age-related neurodegenerative disorder that is currently untreatable. A prominent feature of HD pathology is the reduction of the pro-survival neurotrophin Brain-Derived Neurotrophic Factor (BDNF). Both mRNA and protein levels of BDNF are decreased in the brains of several HD rodent models and in human HD patients. We now report for the first time that this molecular event is mirrored in blood from HD rodent models. While protein levels of BDNF are undetectable in mouse blood, mRNA levels are measurable and diminish during HD progression in transgenic mouse (R6/2) and rat models of HD. Among the eight different BDNF transcripts, only BDNF exon III is transcribed in mouse blood and its expression is progressively compromised in R6/2 mice with respect to age-matched wild-types. Assessment of BDNF mRNA in HD rat blood shows a similar result, which is reinforced by evidence that protein levels of the neurotrophin are also significantly reduced at a symptomatic stage. Finally, we demonstrate that acute and chronic treatment of R6/2 mice with CEP-1347, a mixed lineage kinase (MLK) inhibitor with neuroprotective and neurotrophic effects, leads to increased total BDNF mRNA in blood when compared to untreated R6/2 mice. Our results indicate that alterations in BDNF mRNA levels in peripheral blood are a readily accessible measurement of disease progression and drug efficacy in HD rodent models.

Methods in Molecular Biology, 2009

Each translational approach in medical research forces the establishment of neurobehavioral scree... more Each translational approach in medical research forces the establishment of neurobehavioral screening systems, dedicated to fill the gap between postgenomic generation of state-of-the-art animal models (i.e. transgenic rats) on the one hand and their added value for really predictive experimental preclinical therapy on the other. Owing to these developments in the field, neuroscientists are frequently challenged by the task of detecting discrete behavioral differences in rats. Systematic, comprehensive phenotyping covers these needs and represents a central part of the process. In this chapter, we provide an overview on theoretical issues related to comprehensive neurobehavioral phenotyping of rats and propose specific classical procedures, protocols (similar to the SHIRPA approach in mice), as well as techniques for repeated, intraindividual phenotyping. Neurological testing of rats, motorfunctional screening using the accelerod approach, emotional screening using the social interaction test of anxiety, and testing of sensorimotoric gating functions by prepulse inhibition of the startle response are provided in more detail. This description is completed by an outlook on most recent developments in the field dealing with automated, intra-home-cage technologies, allowing continuous screening in rats in various behavioral and physiological dimensions on an ethological basis.

Journal of Antimicrobial Chemotherapy, 2014

The Laryngoscope, 1993

Intraoperative radiation therapy (IORT) and interstitial radiotherapy (brachytherapy) are highly ... more Intraoperative radiation therapy (IORT) and interstitial radiotherapy (brachytherapy) are highly effective adjunctive treatments for head and neck cancer. The radiotolerance of the carotid artery, pharynx, and mandible to therapeutic doses of these modalities, however, has not been clearly established. To investigate the effects of IORT and interstitial iridium 192 (192Ir) on these structures in the canine, both sides of the neck of 12 mongrel dogs were operated on to expose 4-cm segments of the common carotid artery, pharynx, and mandible. One side of the neck was irradiated in each animal with the opposite side serving as the unirradiated control. The animals were divided into 3 groups of 4 dogs each. The first group received 40-Gy IORT and the second, 60-Gy IORT. In the third group of animals, afterloading catheters were implanted followed by placement of 60-Gy 192Ir. At 2 and 4 months after irradiation, 2 dogs in each treatment group were killed and histopathologic examination of the carotid artery, pharynx, and mandible was performed using hematoxylin-eosin staining. No statistically significant difference between treatment groups was found for carotid artery injury, but a trend for the proportion of fibrosis of the carotid on the irradiated side to increase with dose (P = .125) and time (P = .250) was noted. No apparent or statistically significant difference was found between treatment groups for pharyngeal injury. The greatest histologic changes noted following IORT and 192Ir brachytherapy were found in mandible specimens. The incidence of bone marrow suppression in irradiated mandible specimens versus controls approached statistical significance (P = .062). Osteoradionecrosis (ORN) was noted in the irradiated mandible specimens of two dogs, one of which received 60-Gy IORT and the other 60-Gy interstitial 192Ir. This manuscript reviews animal and clinical investigations relevant to the use of IORT and interstitial radiotherapy to the head and neck. Recommendations are made regarding further animal and clinical research as well as methods of treatment.

Otolaryngology–Head and Neck Surgery, 2012

Objective In patients with laryngeal cancer, pretreatment diagnosis of cartilage invasion often w... more Objective In patients with laryngeal cancer, pretreatment diagnosis of cartilage invasion often warrants a surgical or a bimodal treatment. Controversy exists on whether laryngeal cartilage sclerosis on computed tomography (CT) scan is a sign of tumor invasion. Our objective is to evaluate locoregional, laryngectomy-free, disease-specific, and overall survival in patients with laryngeal cancer with or without laryngeal cartilage sclerosis treated with primary radiation therapy. Study Design Historical cohort study. Setting Tertiary referral university center. Subjects and Methods All laryngeal cancer patients treated with primary radiation therapy between 2002 and 2007 were included. Patients with and without laryngeal cartilage sclerosis on CT scan were identified. Patient, tumor, and treatment data were collected. Univariate and multivariate analyses were conducted using Kaplan-Meier survival analyses and Cox proportional-hazards regression. Results One hundred eleven patients wer...

Journal of Membrane Science, 2011

Journal of Hospital Medicine, 2011

Heart, Lung and Circulation, 2010

Economic Theory, 2004

This paper discusses the existence of an optimal income tax and distinguishes itself from the pre... more This paper discusses the existence of an optimal income tax and distinguishes itself from the previous articles in two respects. In previous papers, the self selection condition was not necessarily consistent with the individual budget constraint. Furthermore, implementability in previous papers was implicit in individual ability, rather than individual income, as the basis of the tax function. We offer a different concept of the self selection conditions: Anti Normal Envy that is consistent with the individual budget constraint and that we show to be equivalent to the competitive equilibrium under a tax function based on income. We then establish the existence of an implementable optimal income tax.