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Nguyen DT, Ogawa R. The sternalis muscle-incidental finding of a rare chest wall muscle variant during keloid excision-chest wall reconstruction. EPLASTY 2012; 12:e36. [PMID: 22893785 PMCID: PMC3417776] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Figures] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
Abstract
INTRODUCTION The sternalis is a rare (strap-like) parasternal muscle that is well known to anatomists, but relatively unknown to clinicians, including surgeons. Familiarity with the muscle is important in avoiding potential confusion when incidentally encountered. When available, the muscle can be harvested for reconstruction of the chest wall or of nearby region. PRESENTATION OF CASE The patient is a 55-year-old man with significant sternal keloids secondary to a previous history of severe acne. The patient desires removal of the keloids. Hence, a decision was made to excise the keloids, followed by immediate reconstruction with a propeller flap. Intraoperative excision of the keloids and undermining of adjacent subcutaneous tissue revealed chest muscle fibers fitting the description of the sternalis muscle. The patient tolerated the procedure without any complications. DISCUSSION The sternalis muscle can be confused for a mass on mammography, but confusion is resolved by computed tomography/magnetic resonance imaging. It has unclear embryonic origin-perhaps a remnant of the panniculus carnosus and/or derivative of a primitive ventral-longitudinal muscle sheet that give rise to the sternocleidomastoid and the rectus abdominis muscles. It is uni- or bilateral and has 1 or 2 bellies. It originates in the intraclavicular region and inserts onto the rectus sheath, costal cartilages, lower ribs, or external oblique aponeurosis. CONCLUSION Not enough is known about the sternalis muscle to draw any conclusion about its utility in reconstructive surgery. It is hoped that cases will be presented in the foreseeable future describing its usage in reconstruction of the neck, chest, abdomen, and perhaps even other places.
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Nguyen DT, Jin C, Thiagalingam A, McEwan AL. A review on electrical impedance tomography for pulmonary perfusion imaging. Physiol Meas 2012; 33:695-706. [DOI: 10.1088/0967-3334/33/5/695] [Citation(s) in RCA: 87] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
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te Wierik MJ, Nguyen DT, Beersma MF, Thijsen SF, Heemstra KA. An outbreak of severe respiratory tract infection caused by human metapneumovirus in a residential care facility for elderly in Utrecht, the Netherlands, January to March 2010. Euro Surveill 2012. [DOI: 10.2807/ese.17.13.20132-en] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Binary file ES_Abstracts_Final_ECDC.txt matches
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Te Wierik MJ, Nguyen DT, Beersma MF, Thijsen SF, Heemstra KA. An outbreak of severe respiratory tract infection caused by human metapneumovirus in a residential care facility for elderly in Utrecht, the Netherlands, January to March 2010. Euro Surveill 2012; 17:20132. [PMID: 22490384] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/31/2023] Open
Abstract
Recognition of infections with human metapneumovirus (HMPV) among institutionalised elderly is rising. When HMPV was found to be the causative agent of an outbreak of pneumonia in a residential care facility for elderly in the Netherlands, an elaborate outbreak investigation was set up, including active surveillance for new cases. From clinical cases, defined by fever (> 38°C) and symptoms of respiratory tract infections, respiratory samples for analyses of viral pathogens by real-time Reverse Transcriptase Polymerase Chain Reaction (rRT-PCR) and blood samples for determination of HMPV-specific IgM and IgG antibody titres were taken. Five staff members and 18 residents fulfilled the clinical case definition. Of those, five residents tested positive for HMPV by rRT-PCR. The combination of rRTPCR and serology identified nine confirmed cases, six probable cases, six possible cases and ruled out two persons as cases. Among residents, the outbreak of HMPV had an attack rate, ranging from 5% for laboratory- confirmed cases, to 13% for clinical cases. This outbreak investigation shows that HMPV is a potential serious pathogen for institutionalised elderly.
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Agnoli K, Schwager S, Uehlinger S, Vergunst A, Viteri DF, Nguyen DT, Sokol PA, Carlier A, Eberl L. Exposing the third chromosome of Burkholderia cepacia complex strains as a virulence plasmid. Mol Microbiol 2011; 83:362-78. [PMID: 22171913 DOI: 10.1111/j.1365-2958.2011.07937.x] [Citation(s) in RCA: 74] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The Burkholderia cepacia complex (Bcc) consists of 17 closely related species of opportunistic bacterial pathogens, which are particularly problematic for cystic fibrosis patients and immunocompromised individuals. Bcc genomes consist of multiple replicons, and each strain sequenced to date has three chromosomes. In addition to genes thought to be essential for survival, each chromosome carries at least one rRNA operon. We isolated three mutants during a transposon mutagenesis screen that were non-pathogenic in a Caenorhabditis elegans infection model. It was demonstrated that these mutants had lost chromosome 3 (c3), and that the observed attenuation of virulence was a consequence of this. We constructed a c3 mini-replicon and used it to cure c3 from strains of several Bcc species by plasmid incompatibility, resulting in nine c3-null strains covering seven Bcc species. Phenotypic characterization of c3-null mutants revealed that they were attenuated in virulence in multiple infection hosts (rat, zebrafish, C. elegans, Galleria mellonella and Drosophila melanogaster), that they exhibited greatly diminished antifungal activity, and that c3 was required for d-xylose, fatty acid and pyrimidine utilization, as well as for exopolysaccharide production and proteolytic activity in some strains. In conclusion, we show that c3 is not an essential chromosomal element, rather a large plasmid that encodes virulence, secondary metabolism and other accessory functions in Bcc bacteria.
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Nguyen DT, Voisin C, Roussignol P, Roquelet C, Lauret JS, Cassabois G. Elastic exciton-exciton scattering in photoexcited carbon nanotubes. PHYSICAL REVIEW LETTERS 2011; 107:127401. [PMID: 22026798 DOI: 10.1103/physrevlett.107.127401] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/31/2011] [Indexed: 05/22/2023]
Abstract
We report on original nonlinear spectral hole-burning experiments in single wall carbon nanotubes that bring evidence of pure dephasing induced by exciton-exciton scattering. We show that the collision-induced broadening in carbon nanotubes is controlled by exciton-exciton scattering as for Wannier excitons in inorganic semiconductors, while the population relaxation is driven by exciton-exciton annihilation as for Frenkel excitons in organic materials. We demonstrate that this singular behavior originates from the intrinsic one-dimensionality of excitons in carbon nanotubes, which display unique hybrid features of organic and inorganic systems.
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Verkaik NJ, Nguyen DT, de Vogel CP, Moll HA, Verbrugh HA, Jaddoe VWV, Hofman A, van Wamel WJB, van den Hoogen BG, Buijs-Offerman RMGB, Ludlow M, de Witte L, Osterhaus ADME, van Belkum A, de Swart RL. Streptococcus pneumoniae exposure is associated with human metapneumovirus seroconversion and increased susceptibility to in vitro HMPV infection. Clin Microbiol Infect 2011; 17:1840-4. [PMID: 21883660 DOI: 10.1111/j.1469-0691.2011.03480.x] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
It remains largely unknown which factors determine the clinical outcome of human metapneumovirus (HMPV) infections. The aim of the present study was to analyse whether exposure to bacterial pathogens can influence HMPV infections. From 57 children, serum samples and colonization data for Haemophilus influenzae, Moraxella catarrhalis, Staphylococcus aureus and Streptococcus pneumoniae were collected at 1.5, 6, 14 and 24 months of age. Seroconversion rates to HMPV were determined and related to bacterial carriage. Frequent nasopharyngeal carriage (≥2 times in the first 2 years of life) of S. pneumoniae, but not of the other three pathogens, was associated with increased seroconversion rates of infants to HMPV at the age of 2 years (frequently vs. less exposed, 93% vs. 59%; p <0.05). Subsequently, the susceptibility of well-differentiated normal human bronchial epithelial cells (wd-NHBE) pre-incubated with bacterial pathogens to in vitro HMPV infection was evaluated. Pre-incubation of wd-NHBE with S. pneumoniae resulted in increased susceptibility to infection with HMPV-enhanced green fluorescent protein (EGFP), as determined by enumeration of EGFP-positive cells. This was not the case for cells pre-incubated with H. influenzae, M. catarrhalis on S. aureus. We conclude that exposure to S. pneumoniae can modulate HMPV infection.
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Nguyen DT, Oki K, Hyakusoku H, Ogawa R. Upper lip Basal cell carcinoma reconstruction based on anatomical characteristics using skin-mucosa double opposing v-y advancement flap. EPLASTY 2011; 11:e26. [PMID: 21625614 PMCID: PMC3097993] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
BACKGROUND Upper lip defects less than one-fourth of total upper lip length are typically closed directly, but larger defects require reconstruction. Established techniques, such as the Abbe/Estlander flap, often require multiple procedures. This report discusses a single-step method, involving a skin-mucosa double opposing V-Y advancement flap, which was utilized to reconstruct the upper lip after basal cell carcinoma extirpation. METHODS The patient is a 54-year-old woman who presented with a 2.5-cm basal cell carcinoma in the right upper lip. Two parallel V-Y flaps were designed, on "parallel" planes of the skin and mucosa, and were advanced following wedge resection of tumor and portion of the adjacent orbicularis oris muscle. Skin/mucosa flap edges were brought to create a new skin-vermilion border, which was then sutured onto existing skin-vermilion border edges. RESULTS The patient was evaluated 6 months after the operation, and examination showed well-healed flaps with excellent aesthetic and functional results. There was a thin, marginal scar, where reconstructed vermilion (medial) edge was sutured to native vermilion. CONCLUSIONS It was considered that this method could reconstruct anatomical features and function of the lip precisely. It seems that within certain limits (probably between one-fourth and one-third of total upper lip length), skin-mucosa double opposing V-Y advancement flaps appear to be the preferred method for upper lip reconstruction.
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Nguyen DT, Choi H, Jo H, Kim JH, Dirisala VR, Lee KT, Kim TH, Park KK, Seo K, Park C. Molecular characterization of the human ABO blood group orthologus system in pigs. Anim Genet 2011; 42:325-8. [PMID: 21554350 DOI: 10.1111/j.1365-2052.2010.02152.x] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
The selection and use of animals with blood group 0 in the process of transplanting pig organs or tissues into humans can positively contribute to the control of acute immune rejection due to differences in blood groups. Exon-specific PCRs for the porcine blood group A transferase gene against genomic DNA from either blood group A or 0 animals resulted in the amplification failure of the A0 blood group gene exon 8 from blood group 0 animals. To characterize the genetic abnormality in the genome of blood group 0 animals, we screened bacterial artificial chromosome (BAC) clones from a Korean native pig BAC library which had the blood group 0 allele, and carried out shotgun sequencing. The analysis showed that the 0 allele has a large deletion between exon 7 of the A0 blood group gene and the neighbouring SURF6. We also showed that the ABO blood group antigens in humans and the A0 blood group antigens in pigs are coded by mutations within the orthologous glycosyltransferase gene. In addition, we developed a multiplex genotyping method for the porcine A0 blood group gene.
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Song G, Nguyen DT, Pietramaggiori G, Scherer S, Chen B, Zhan Q, Ogawa R, Yannas IV, Wagers AJ, Orgill DP, Murphy GF. Use of the parabiotic model in studies of cutaneous wound healing to define the participation of circulating cells. Wound Repair Regen 2010; 18:426-32. [PMID: 20546556 DOI: 10.1111/j.1524-475x.2010.00595.x] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023]
Abstract
Previous experimental studies to assess the contribution of blood-borne circulating (BBC) cells to cutaneous wound healing have relied on discontinuous pulsing of labeled BBC elements or bone marrow transplant protocols. Such approaches do not allow the examination of stable BBC cells that have matured in a physiologically normal host. We have used a parabiotic murine model for cutaneous wound healing to evaluate the relative contribution of stable populations of peripheral blood cells expressing the green fluorescent protein (GFP) transgene in otherwise normal animals. Circulating cells (mature and immature) expressing the GFP transgene were easily detected and quantified in wounds of GFP- parabiotic twins during all evaluated stages of the healing response. Using multiple antibody probes, the relative contribution of various subsets of BBC cells could be comparatively assessed. In early wounds, some cells expressing mesenchymal epitopes were documented to be of hematopoietic origin, indicating the utility of this model in assessing cell plasticity in the context of tissue regeneration and repair. Application of this approach enables further investigation into the contribution of peripheral blood in normal and abnormal healing responses.
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Knight MAF, Nguyen DT, Kobayashi MR, Evans GRD, Cheng MH. Incidental positive internal mammary lymph nodes: a multiple international institutional investigation. J Reconstr Microsurg 2008; 24:197-202. [PMID: 18459089 DOI: 10.1055/s-2008-1076088] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
Abstract
The internal mammary lymph node is the second most frequent site of nodal metastasis. With an increase in breast free flap reconstruction utilization of the internal mammary vessels, identification of these internal mammary lymph node metastases will become more prevalent. A chart review documented 75 free transverse rectus abdominis myocutaneous flaps cases performed at Kaiser Bellflower from 1998 to 2004. Between March 2000 and January 2006 there were 157 autologous breast reconstructions (122 DIEP flaps, 10 GAP flaps, 15 SIEA flaps, 7 free transverse rectus abdominis flaps, and 1 SCIA flap) using internal mammary vessels as the recipient site at the Chang Gung Memorial Hospital. A literature review was conducted to survey the current protocols in the surgical, oncological, and radiological communities. A population of 232 patients with breast reconstruction via free flaps was identified. The age range was 29 to 65 years. With the exception of the five cases presented, no other incidence of positive internal mammary lymph nodes was identified. Failure to account for the status of the internal mammary lymph nodes may risk understaging and preclude appropriate treatment stratification. With more frequent utilization of the internal mammary vessels, discussions regarding breast reconstruction should take this new oncological focus into consideration.
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Nguyen DT, Citgez E, van Brussel BL, Vermeulen FEE, Plokker HWM, Voors AA. Systolic blood pressure and cardiac mortality over 24 years after venous coronary bypass surgery. J Hum Hypertens 2007; 21:330-2. [PMID: 17287840 DOI: 10.1038/sj.jhh.1002157] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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Knight MAK, Nguyen DT, Kobayashi MR, Evans GRD. Institutional Review of Free TRAM Flap Breast Reconstruction. Ann Plast Surg 2006; 56:593-8. [PMID: 16721068 DOI: 10.1097/01.sap.0000202226.92967.f0] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
INTRODUCTION A 10-year experience with breast reconstruction in a university hospital was recently reviewed. The purpose of this study was to determine the subtypes of breast reconstructive procedures and to evaluate the frequency and change in technique over time of free TRAM (transverse rectus abdominis muscle) flap breast reconstruction performed at one institution. Trends in the development of the procedure over this period were also reviewed. MATERIALS & METHODS Between November 1994 and September 2004, a 10-year retrospective chart review was conducted. The indications for mastectomy and reconstruction were determined. The median age was 48 (range 31-66). The range of follow-up was 2 to 71 months, with a median of 19.5 months. The mean follow-up was 23.5 months. Outcome data were grouped into 2 consecutive 5-year periods (period 1: 1994-1998; period 2: 1999-2004) and evaluated for changes over time in techniques and outcome. Statistical analysis (Decision Analyst, Inc., STATS Statistics software, version 1.1, 1998) was performed using the difference between 2 proportions module to assess the probability of a significant difference in the data for period 1 and period 2 parameters. RESULTS Over a 10-year period, 117 patients underwent breast reconstruction. This consisted of 12 pedicle procedures (11.3%), including 1 bipedicle flap (0.9%) and 2 bilateral pedicle procedures (1.8%). There were 3 latissimus dorsi pedicle flaps (2.8%). Sixteen patients (15.1%) received tissue expander or implant reconstructions. Of the 117 patients, 79 underwent free flap breast reconstruction. Of the 79 free-flap patients, 22 (27.8%) had bilateral procedures, for a total of 101 free flaps performed in these 79 patients. Fifty-two patients underwent immediate reconstruction (65.8%) and 25 were delayed (31.6%) reconstructions using either deep inferior epigastric artery perforator (DIEP) flaps (4 = 3.9%) or free TRAM flaps (97 = 96.0%). A muscle-sparing technique was used in 43 of the 97 free TRAM flaps (44.3%). The preferred vascular inflow was the internal mammary artery, which was used in 66 out of 101 flaps (65.3%). The rate of anastomotic revision (arterial and venous) was 4.9%. The majority of cases used a 2.5-mm venous coupler (65.3%). In 2 of the free TRAM cases, there was insufficient volume to establish the patients preexisting volume. Therefore, at the patient's request, immediate implants were used to augment the reconstruction. The average hospital stay was 8.13 days, and the average intensive care stay was 4.59 days. When assessed for trends over time, we noted a reduction in our hospital length of stay and our ICU length of stay. CONCLUSION The experience with free tissue breast reconstruction reveals predominant use of the TRAM flap. This is justified by the reliability of this flap and the advances in achieving esthetic breast reconstruction. Additionally, we have begun performing DIEP free-flap reconstructions. Our clinical practice has evolved concurrent with standards of care, as noted by the increase in use of muscle-sparing techniques and the reduction in the use of dextran. We do not routinely use therapeutic anticoagulation in our cases. Our hospital length of stay and average intensive care length of stay have also decreased over time, consistent with a system-wide effort to increase the efficiency of healthcare delivery.
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Krug N, Hohlfeld JM, Geldmacher H, Larbig M, Heermann R, Lavallee N, Nguyen DT, Petzold U, Hermann R. Effect of loteprednol etabonate nasal spray suspension on seasonal allergic rhinitis assessed by allergen challenge in an environmental exposure unit. Allergy 2005; 60:354-9. [PMID: 15679722 DOI: 10.1111/j.1398-9995.2005.00703.x] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
BACKGROUND Loteprednol etabonate (LE) is a novel soft steroid that was designed to improve the benefit/risk ratio of topical corticosteroid therapy. This study assesses the clinical efficacy and safety of three different doses of LE nasal spray in seasonal allergic rhinitis (SAR). METHODS In this single-center, double-blind, placebo-controlled, parallel-group trial 165 subjects with SAR to grass pollen received daily single doses of either 100, 200, 400 microg LE nasal spray, or placebo for 14 days. The patients underwent three 4-h allergen challenges with grass pollen in an environmental exposure unit at a screening visit (baseline) and on days 7 and 14 of treatment. Standardized nasal symptom scores were obtained every 20 min. Nasal flow, nasal secretions, and FEV(1) were measured every hour during allergen challenges. RESULTS After 14 days of treatment, patients who received 400 microg LE had significantly lower total nasal symptom scores compared with those receiving placebo (P = 0.007). LE400 reduced rhinorrhea, nasal congestion, nasal itching, the amount of nasal secretions, and improved nasal flow as compared with placebo (P < 0.05). LE100 and LE200 were not significantly different from placebo. All treatments were well tolerated. CONCLUSIONS Loteprednol 400 microg once daily is superior to placebo and the only effective dose tested in improving nasal symptoms and objective parameters in patients with SAR.
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Ehara M, Nguyen BM, Nguyen DT, Toma C, Higa N, Iwanaga M. Drug susceptibility and its genetic basis in epidemic Vibrio cholerae O1 in Vietnam. Epidemiol Infect 2004; 132:595-600. [PMID: 15310160 PMCID: PMC2870139 DOI: 10.1017/s0950268804002596] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
Abstract
The drug susceptibility and genes responsible for the drug resistance of Vibrio cholerae O1 isolated in Vietnam in 1995, 2000 and 2002 were studied. The strains isolated in 1995 were resistant to streptomycin and harboured the class I integron which contained the aadA1 gene responsible for streptomycin resistance. The strains isolated in 2000 were devoid of a class I integron but were multiple-drug resistant and harboured SXT constin, with several drug-resistant genes. The genes responsible for streptomycin resistance were strA and strB. The strains isolated in 2002 were sensitive to all drugs examined, and the organisms were devoid of both class I integron and SXT constin. Cholera outbreaks in the three periods examined (1995, 2000 and 2002) were apparently due to different categories of V. cholerae O1.
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Devictor D, Nguyen DT. Fins de vie en rænimation pediatrique. Arch Pediatr 2003; 10 Suppl 1:167s-169s. [PMID: 14509785 DOI: 10.1016/s0929-693x(03)90425-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
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Houssin C, Nguyen DT, Leblon G, Bayan N. S-layer protein transport across the cell wall of Corynebacterium glutamicum: in vivo kinetics and energy requirements. FEMS Microbiol Lett 2002; 217:71-9. [PMID: 12445648 DOI: 10.1111/j.1574-6968.2002.tb11458.x] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022] Open
Abstract
Corynebacteria are Gram-positive bacteria with a very peculiar cell envelope structure as it is constituted of an inner membrane and an outer membrane-like structure. Protein secretion in Corynebacterium glutamicum was studied in vivo, using the S-layer protein PS2 as a model. We show that different variants of PS2 protein are exported through the whole cell envelope with a half-life ranging between 2 and 4 min, by a two-step mechanism. The first step, which is over after about 1.5 min, is ATP- and proton motive force-dependent and may correspond to translocation across the inner membrane via the 'Sec' machinery. The second step, across the cell wall and the outer mycolate layer, is rapid but independent of energy sources. This very efficient secretion process across the mycolate layer raises the question of the existence in this layer of a specific machinery.
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Dickson KM, Bergeron JJM, Shames I, Colby J, Nguyen DT, Chevet E, Thomas DY, Snipes GJ. Association of calnexin with mutant peripheral myelin protein-22 ex vivo: a basis for "gain-of-function" ER diseases. Proc Natl Acad Sci U S A 2002; 99:9852-7. [PMID: 12119418 PMCID: PMC125041 DOI: 10.1073/pnas.152621799] [Citation(s) in RCA: 85] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023] Open
Abstract
Schwann cell-derived peripheral myelin protein-22 (PMP-22) when mutated or overexpressed causes heritable neuropathies with a previously unexplained "gain-of-function" endoplasmic reticulum (ER) retention phenotype. In wild-type sciatic nerves, PMP-22 associates in a specific, transient (t(1/2 ) approximately equal to 11 min), and oligosaccharide processing-dependent manner with the lectin chaperone calnexin (CNX), but not calreticulin nor BiP. In Trembler-J (Tr-J) sciatic nerves, prolonged association of mutant PMP-22 with CNX is found (t(1/2) > 60 min). In 293A cells overexpressing PMP-22(Tr-J), CNX and PMP-22 colocalize in large intracellular structures identified at the electron microscopy level as myelin-like figures with CNX localization in the structures dependent on PMP-22 glucosylation. Similar intracellular myelin-like figures were also present in Schwann cells of sciatic nerves from homozygous Trembler-J mice with no detectable activation of the stress response pathway as deduced from BiP and CHOP expression. Sequestration of CNX in intracellular myelin-like figures may be relevant to the autosomal dominant Charcot-Marie-Tooth-related neuropathies.
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Morize V, Salomon L, Nguyen DT, Rosenheim M, Desfosses G. Palliative care: are we talking about the same patients? Palliat Med 2002; 16:65-6. [PMID: 11963455 DOI: 10.1191/0269216302pm485xx] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
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Nguyen DT, Frank-Soltysiak M, Bisson M. [Study of terminally ill patients' needs in an university hospital]. SANTE PUBLIQUE (VANDOEUVRE-LES-NANCY, FRANCE) 2001; 13:339-47. [PMID: 11963531] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/24/2023]
Abstract
Within the framework of a project to create a Mobile Palliative Care Unit, in May 2000 we conducted an evaluation of the needs of patients undergoing palliative care in a university hospital centre. Thanks to the use of a standardised questionnaire, a team of doctors and nurses for each service was able to describe the symptoms, treatments and social and family situations as well as assess the eventual outcome of the patients hospitalised in their service who were in an advanced or terminal phase. In total, the study included 52 cases (5.5% of available beds). 81% of patients reported suffering from physical discomfort and 70% from psychological distress. A specific treatment for the disease in question was maintained in 28% of the cases. In 24% of the cases, the patient had social problems. Among all of the patients, 31% were on the waiting list to be transferred to a different location.
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Yao ZQ, Nguyen DT, Hiotellis AI, Hahn YS. Hepatitis C virus core protein inhibits human T lymphocyte responses by a complement-dependent regulatory pathway. JOURNAL OF IMMUNOLOGY (BALTIMORE, MD. : 1950) 2001; 167:5264-72. [PMID: 11673541 DOI: 10.4049/jimmunol.167.9.5264] [Citation(s) in RCA: 116] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
Complement proteins are involved in early innate immune responses against pathogens and play a role in clearing circulating viral Ags from the blood of infected hosts. We have previously demonstrated that hepatitis C virus (HCV) core, the first protein to be expressed and circulating in the blood of infected individuals, inhibited human T cell proliferative response through interaction with the complement receptor, globular domain of C1q receptor (gC1qR). To investigate the mechanisms of HCV core/gC1qR-induced inhibition of T cell proliferation, we examined the effect of core protein on the early events in T cell activation. We found that HCV core inhibited phosphorylation of extracellular signal-regulated kinase (ERK) and mitogen-activated ERK kinase (MEK). HCV core-induced impairment of ERK/MEK mitogen-activated protein kinase resulted in the inhibition of IL-2 and IL-2Ralpha gene transcription, which led to the inhibition of IL-2 production and high-affinity IL-2R expression. Importantly, the ability of anti-gC1qR Ab treatment to reverse HCV core-induced inhibition of ERK/MEK phosphorylation reveals that the interaction between HCV core and gC1qR is linked to the interference of ERK/MEK mitogen-activated protein kinase activation. These results imply that HCV core-induced blockage of intracellular events in T cell activation by a complement-dependent regulatory pathway may play a critical role in the establishment of HCV persistence during the acute phase of viral infection.
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Nguyen DT, Houssin C, Bayan N. Study of mycoloyl transferase transport across the cell envelope of Corynebacterium glutamicum. FEMS Microbiol Lett 2001; 201:145-50. [PMID: 11470353 DOI: 10.1111/j.1574-6968.2001.tb10748.x] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022] Open
Abstract
PS1 is a major exported protein of Corynebacterium glutamicum homologous to mycobacterial antigen 85. It is largely associated with the mycolic acid-containing cell wall and acts as a mycoloyl transferase. The transport of PS1 to the cell wall is slow and occurs through two energetically distinct steps: the first one, which includes processing by signal peptidase, is rapid and inhibited by sodium azide or carbonyl cyanide m-chlorophenylhydrazone. This step is probably associated with translocation across the cytoplasmic membrane. The kinetics of the second step depend on the size of the polypeptide chain to be transported but neither ATP nor proton motive force is required. This step may correspond to the diffusion of PS1 across the cell wall to its final location.
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Devictor DJ, Nguyen DT. Forgoing life-sustaining treatments: how the decision is made in French pediatric intensive care units. Crit Care Med 2001; 29:1356-9. [PMID: 11445686 DOI: 10.1097/00003246-200107000-00010] [Citation(s) in RCA: 64] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
OBJECTIVES The decision to forgo life support is frequently made in pediatric intensive care units (PICUs). A group of experts is currently preparing recommendations for guidelines concerning this decision-making process in France. We have performed a prospective study to help the experts. This study documents how children die in French PICUs and how the decision to limit life support is made. DESIGN A multicenter, prospective, cross-sectional study. SETTING Thirty-three multidisciplinary PICUs in university hospitals. PATIENTS All consecutive deaths were recorded over a 4-month period. Children who died after a medical decision to forgo life-sustaining treatment were included in group 1 and children who died from other causes were included in group 1. MAIN RESULTS A total of 264 consecutive children died, 40.1% from group 1 and 59.8% from group 2. Patients of both groups were primarily admitted for acute respiratory failure (group 1, 50.8%; group 2, 52.6%). Neurologic emergencies were more frequent in patients in group 1, whereas patients with cardiovascular failures were more frequent in group 2. When there was a question of whether to pursue life-sustaining treatment, the parents' opinions were recorded in 72.1% of cases. A specific meeting was called to make this decision in 80.1% of cases. This meeting involved the medical staff in all cases. Parents were aware of the meeting in 10.7% of cases. The conclusion of the meeting was reported to the parents in 18.7% of cases and documented in the patient's medical record in 16% of cases. Experts who were not members of the PICU staff were invited to give their opinion in 62.2% of cases. CONCLUSIONS The decision to forgo life-sustaining treatment is frequently made for children dying in French PICUs. Guidelines must be available to help the medical staff reach this decision. Knowledge of the decision-making process in French PICUs provides the experts with information needed to elaborate such recommendations.
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Tasu JP, Takun K, Rocher L, Livartowski J, Nguyen DT, Miquel A, Spira A, Ellrodt A, Bléry M. [Evaluation of plain abdominal radiography prescriptions in a university hospital center]. Presse Med 2001; 30:1097-101. [PMID: 11484400] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/21/2023] Open
Abstract
OBJECTIVES The aim of this study was to evaluate the prescription, impact and diagnostic utility of plain abdominal radiography in a University Hospital. METHODS Plain abdominal radiography series performed over 15 consecutive days were evaluated for quality and agreement with the patient's clinical status. Agreement between the final diagnosis and the radiographic findings were also compared. Contribution of plain abdominal radiography to final diagnosis was assessed on the basis of the conclusions on the hospital discharge report or from those drawn from a telephone survey. The same relationship was also assessed in terms of clinician status (medical student, resident physician, senior physician). RESULTS The series included 175 radiography series (11.6 per day). In 86% of the cases, the choice of views was adapted to the clinical context. In 14% it was not. The quality of the x-rays was found to be unsatisfactory in 17%, good in 63% and excellent in 20%. The radiography was considered to be contributive to the final diagnosis in 13% of the cases and non-contributive in 87%. Clinician status was not correlated with the degree of usefulness for final diagnosis. Finally, the prescription was in agreement with standard guidelines in 28% of the cases and not in agreement in 72%. CONCLUSION Plain abdominal radiographs are neither sensitive nor specific, frequently misleading, and costly per specific and correct diagnosis. Better physician awareness is required to limit the number of unnecessary examinations.
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Chui KK, Rogers GC, Kashina AM, Wedaman KP, Sharp DJ, Nguyen DT, Wilt F, Scholey JM. Roles of two homotetrameric kinesins in sea urchin embryonic cell division. J Biol Chem 2000; 275:38005-11. [PMID: 11006281 DOI: 10.1074/jbc.m005948200] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
To improve our understanding of the roles of microtubule cross-linking motors in mitosis, we analyzed two sea urchin embryonic kinesin-related proteins. It is striking to note that both of these proteins behave as homotetramers, but one behaves as a more compact molecule than the other. These observations suggest that these two presumptive motors could cross-link microtubules into bundles with different spacing. Both motors localize to mitotic spindles, and antibody microinjection experiments suggest that they have mitotic functions. Thus, one of these kinesin-related proteins may cross-link spindle microtubules into loose bundles that are "tightened" by the other.
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