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Nguyen K, Bourdin A, Barbotte E, Vachier I, Paganin F, Godard P, Bousquet J, Vignola A, Chanez P. 6 Facteurs de risque de mortalité dans une cohorte de 52 asthmatiques sévères suivis pendant 10 ans. Rev Mal Respir 2004. [DOI: 10.1016/s0761-8425(04)71632-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
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Nguyen K, Philip N, Suchet L, Azulay JP, Pouget J. Syndrome oculodentodigital révélé par une paraparésie spastique progressive. Rev Neurol (Paris) 2004; 160:83-5. [PMID: 14978398 DOI: 10.1016/s0035-3787(04)70851-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
Abstract
Oculodentodigital syndrome (ODD) is a rare congenital disorder which associates eyes and facial abnormalities, defects in teeth enamel and type III syndactyly. The causal genetic defect in this syndrome is still unknown. Some patients with ODD syndrome also manifest spastic paraparesis. In most cases, inheritance is autosomal dominant with variable clinical expression. Herein, we report on a patient with ODD syndrome, who was referred for evaluation of spastic paraplegia. Our observations show that ODD syndrome can be recognized in late adulthood and revealed by spastic paraplegia.
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Duncan LW, Graham JH, Dunn DC, Zellers J, McCoy CW, Nguyen K. Incidence of Endemic Entomopathogenic Nematodes Following Application of Steinernema riobrave for Control of Diaprepes abbreviatus. J Nematol 2003; 35:178-186. [PMID: 19265992 PMCID: PMC2620623] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/27/2023] Open
Abstract
Control of Diaprepes abbreviatus by endemic and exotic entomopathogenic nematodes (EPN) was monitored during 2000-2001 in two citrus orchards in central Florida (Bartow and Poinciana). Caged sentinel insect larvae were buried beneath citrus trees for 7 days at 1 to 2-month intervals from April to October each year. At Bartow, the survey occurred in experimental plots that were (i) not treated with commercial EPN, (ii) treated twice annually since 1998 with commercially formulated Steinernema riobrave, or (iii) treated twice annually with S. riobrave and liquid fertilization (15 times/year) occurred in place of dry fertilizer (3 times/year) used in the other treatments. Four endemic EPN species, in addition to S. riobrave, were recovered from the sandy soil at Bartow: S. diaprepesi, Heterorhabditis zealandica, H. indica, and H. bacteriophora. Mean insect mortality in control plots was 39.4% (range = 13% to 74%), with seasonal maxima in May to July each year. Endemic EPN were recovered from 55% (range = 22% to 81%) of the cadavers each month. Total numbers of endemic EPN recovered in all plots during 2 years were directly related to the numbers of adult weevils (D. abbreviatus and Pachnaeus litus) captured in modified Tedder's traps and inversely related to recovery of S. riobrave. Insect mortality was higher and cadavers containing endemic EPN were more numerous in untreated control plots than in S. riobrave-treated plots, except during months in which S. riobrave was applied. In treated plots, endemic EPN were recovered from cadavers at twice the rate of S. riobrave. Suppression of endemic EPN in plots treated with S. riobrave, combined with inferior persistence by the introduced species, may have attenuated the net efficacy of S. riobrave against D. abbreviatus. In contrast, H. indica was the only endemic nematode recovered from the sandy clay loam soil at Poinciana, where the average mortality of D. abbreviatus was 12% (range 3% to 20%) and incidence of H. indica did not exceed 8%. Results of these surveys suggest that the regional patterns in the abundance and damage to citrus caused by D. abbreviatus in Florida are regulated by endemic EPN and other soilborne enemies of the weevil.
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Duncan LW, Dunn DC, Bague G, Nguyen K. Competition Between Entomopathogenic and Free-Living Bactivorous Nematodes in Larvae of the Weevil Diaprepes abbreviatus. J Nematol 2003; 35:187-193. [PMID: 19265993 PMCID: PMC2620622] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/27/2023] Open
Abstract
Field and laboratory experiments were conducted to determine the degree to which free-living, bactivorous nematodes (FLBN) are able to competitively displace entomopathogenic nematodes (EPN) from insect cadavers. Two hundred larvae of the insect Diaprepes abbreviatus were buried at regular intervals during 2 years in experimental plots that were untreated or treated twice annually with Steinernema riobrave. Larvae were recovered after 7 days, and nematodes emerging from cadavers during the next 30 days were identified. The monthly prevalence of FLBN was directly related to that of S. riobrave (r = 0.38; P = 0.001) but was not related to the prevalence of the endemic EPN, S. diaprepesi, Heterorhabditis zealandica, H. indica, or H. bacteriophora (r = 0.02; P = 0.80). In a second experiment, treatment of small field plots with S. riobrave increased the prevalence of insect cadavers in which only FLBN were detected compared to untreated controls (30% vs. 14%; P = 0.052), and increased numbers of FLBN per buried insect by more than 10-fold. In the laboratory, sand microcosms containing one D. abbreviatus larva were treated with (i) the FLBN, Pellioditis sp.; (ii) S. riobrave; (iii) S. riobrave + Pellioditis; or (iv) neither nematode. Insect mortality was higher in the presence of both nematodes (57%) than when S. riobrave was alone (42%) (P = 0.01). An average of 59.2 Pellioditis sp. g(-1) insect body weight emerged in the presence of S. riobrave, whereas 6.2 nematodes g(-1) insect were recovered in the absence of the EPN (P = 0.01). Pellioditis sp. reduced the number of S. riobrave per cadaver by 84%; (P = 0.03), and per available insect by 82% (P = 0.001), compared to S. riobrave alone. Population size of S. diaprepesi was not affected by Pellioditis sp. in experiments of the same design. Faster development (P = 0.05) and nutrient appropriation within the insect cadaver by S. diaprepesi compared to S. riobrave may increase the fitness of the former species to compete with Pellioditis sp. The results of these studies demonstrate the potential of FLBN to regulate population densities of EPN and to dampen estimates of EPN-induced mortality of insect pests in the field.
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Pringsheim T, Diksic M, Dobson C, Nguyen K, Hamel E. Selective decrease in serotonin synthesis rate in rat brainstem raphe nuclei following chronic administration of low doses of amitriptyline: an effect compatible with an anti-migraine effect. Cephalalgia 2003; 23:367-75. [PMID: 12780767 DOI: 10.1046/j.1468-2982.2003.00526.x] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
The effects of chronic, low-dose amitriptyline on serotonin (5-HT) synthesis rate were measured in rat brain using autoradiography and the trapping of alpha-[14C]-methyl-L-tryptophan (alpha-[14C]-MTrp). Rats received amitriptyline (2 mg/kg per day) or saline via intraperitoneal osmotic minipumps for 21 days. Amitriptyline had no effect on any physiological parameters measured, or on free or total plasma tryptophan levels. However, amitriptyline exerted selective decreases of 15% and 17% (P < 0.001) in serotonin synthesis rates in the dorsal and median raphe nuclei, respectively. There was no reduction in any of the projection areas studied, including the cerebral cortex, hippocampus, thalamus, hypothalamus or striatum. The data suggest that chronic low doses of amitriptyline can lead to sustained 5-HT re-uptake inhibition selectively in the raphe nuclei, an effect compatible with tonic activation of 5-HT(1A) autoreceptors and inhibition of 5-HT synthesis. The failure of chronic amitriptyline treatment to affect 5-HT synthesis rate in the projection areas may ensure an adequate regulation of pain pathways implicated in migraine headache, an effect possibly related to amitriptyline anti-migraine efficacy.
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Liang Q, Nguyen K, Satyamurthy N, Barrio JR, Phelps ME, Gambhir SS, Herschman HR. Monitoring adenoviral DNA delivery, using a mutant herpes simplex virus type 1 thymidine kinase gene as a PET reporter gene. Gene Ther 2002; 9:1659-66. [PMID: 12457279 DOI: 10.1038/sj.gt.3301899] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2001] [Accepted: 01/15/2002] [Indexed: 11/09/2022]
Abstract
Current gene therapy protocols often suffer from an inability to monitor the site, level and persistence of gene expression following somatic DNA delivery. Herpes simplex virus 1 thymidine kinase (HSV1-tk) is currently under intensive investigation as a reporter gene for in vivo imaging of reporter gene expression. The presence of the HSV1-tk reporter gene is repetitively and non-invasively monitored by systemic injection of positron-emitting, radionuclide-labeled thymidine analogues or acycloguanosine HSV1-TK substrates and subsequent detection, by positron emission tomography, of trapped, phosphorylated product. To improve the efficacy of the HSV1-tk PET reporter gene system, both alternative substrates and mutations in the HSV1-tk gene have been described. We used a replication defective adenovirus to deliver the HSV1-sr39tk mutant enzyme and the wild-type HSV1-tk enzyme to mice. HSV1-sr39TK demonstrates greater sensitivity than wild-type HSV1-TK enzyme in vivo, using 9-[(4-[(18)F]fluoro-3-hydroxymethylbutyl)guanine as probe, following adenovirus-mediated hepatic expression in mice. Using this adenoviral delivery system, the location, magnitude and duration of HSV1-sr39tk PET reporter gene expression could be non-invasively, quantitatively and repetitively monitored for over 3 months by microPET.
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Kaminski JM, Nguyen K, Buyyounouski M, Pollack A. Prostate cancer gene therapy and the role of radiation. Cancer Treat Rev 2002; 28:49-64. [PMID: 12027414 DOI: 10.1053/ctrv.2002.0250] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
Abstract
Even though prostate cancer is detected earlier than in the pre-PSA era, prostate cancer is the second leading cause of cancer mortality in the American male. Prostate cancer therapy is not ideal, especially for high-risk localized and metastatic cancer; therefore, investigators have sought new therapeutic modalities such as angiogenesis inhibitors, inhibitors of the cell signaling pathway, vaccines, and gene therapy. Gene therapy has emerged as potential therapy for both localized and systemic prostate cancer. Gene therapy has been shown to work supra-additively with radiation in controlling prostate cancer in vivo. With further technological advances in radiation therapy, gene therapy, and the understanding of prostate cancer biology, gene therapy will potentially have an important role in prostate cancer therapy.
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Cox CE, Salud CJ, Cantor A, Bass SS, Peltz ES, Ebert MD, Nguyen K, Reintgen DS. Learning curves for breast cancer sentinel lymph node mapping based on surgical volume analysis. J Am Coll Surg 2001; 193:593-600. [PMID: 11768674 DOI: 10.1016/s1072-7515(01)01086-9] [Citation(s) in RCA: 121] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
BACKGROUND Implementation of new procedures, including lymphatic mapping for breast cancer, must be done and overseen by the medical community in a responsible way to ensure that the procedures are performed correctly. This study addresses the issues of adequacy of training and certification of surgeons performing lymphatic mapping. Ensuring quality in surgical care requires outcomes measures that are described in this study. STUDY DESIGN Sixteen surgeons performed lymphatic mapping in 2,255 patients with breast cancer using a combination blue dye and Tc99m-labeled sulfur colloid to identify the sentinel lymph nodes (SLNs). All participants were trained in a 2-day CME-accredited course. The Cox learning curve model (total number of mapping failures/total number of mapping cases) for a consecutive series of lymphatic mapping cases is described. The relationship of the Surgical Volume Index, the cases performed in a 30-day period, to the failure rate for each surgeon was modeled as a logistic regression curve (y = e(a+bx)/[1 + e(a+bx)]). RESULTS Surgeons performing less than three SLN biopsies per month had an average success rate of 86.23% +/- 8.30%. Surgeons performing three to six SLN biopsies per month had a success rate of 88.73% +/- 6.36%. Surgeons performing more than six SLN biopsies per month had a success rate of 97.81% +/- 0.44%. CONCLUSIONS This experience defines a learning curve for lymphatic mapping in breast cancer patients. Data suggest that increased volumes lead to decreased failure rates. These data provide surgeons performing SLN biopsy with a new paradigm for assessing their skill and adequacy of training and describes the relationship between volume of cases performed and success rate of SLN detection.
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Dupont E, Cox CE, Nguyen K, Salud CJ, Peltz ES, Whitehead GF, Ebert MD, Ku NN, Reintgen DS. Utility of internal mammary lymph node removal when noted by intraoperative gamma probe detection. Ann Surg Oncol 2001; 8:833-6. [PMID: 11776499 DOI: 10.1007/s10434-001-0833-7] [Citation(s) in RCA: 37] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
BACKGROUND Lymphatic mapping (LM) for breast cancer has made internal mammary node (IMN) detection practical and dependable. This study demonstrates the necessity of IMN removal when suggested by intraoperative radioguided surgery detection. METHODS From April 1998 to July 2000, 1273 patients underwent LM for breast cancer. LM was performed using the combined dye and radiocolloid technique. Patients were scanned operatively with a gamma probe over the IMN area, and most underwent preoperative lymphoscintigraphy. Nodes were removed from patients in whom radioactivity was detected in the internal mammary area. RESULTS Thirty of the 1273 (2.4%) patients mapped had at least one IMN removed. Twenty-two of 30 (73.3%) had inner quadrant lesions. Five of 30 (16.7%) patients had IMNs that were positive for metastatic disease. Three of these five had no metastatic spread to the axillary sentinel lymph node (SLN). One of thirty (3.3%) patients with IMN localization had neither hot nor blue nodes detected in an SLN procedure. CONCLUSIONS Radioguided SLN detection should be attempted in the IMN basin with all tumors. If an IMN is identified, it should be removed. IMN biopsy is a feasible, low-risk procedure when directed by radioguided LM and provides a guide for radiotherapy for patients with positive IMNs.
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Williamson J, Christensen G, Lerma F, Carlson B, Chao K, Bae T, Nguyen K, Grigsby P, Matthews J, Vannier M. 3D image-based dose planning of intracavitary brachytherapy and teletherapy of gynecological tumors: registration of cumulative dose via deformable anatomic templates. Int J Radiat Oncol Biol Phys 2001. [DOI: 10.1016/s0360-3016(01)02543-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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Dupont EL, Salud CJ, Peltz ES, Nguyen K, Whitehead GF, Ku NN, Reintgen DS, Cox CE. Clinical relevance of internal mammary node mapping as a guide to radiation therapy. Am J Surg 2001; 182:321-4. [PMID: 11720663 DOI: 10.1016/s0002-9610(01)00720-6] [Citation(s) in RCA: 44] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
BACKGROUND The surgical management of breast cancer has changed markedly with the development of lymphatic mapping and sentinel lymph node (SLN) biopsy. Lymphatic mapping technique varies with respect to injection method, mapping agent, and surgical technique. The decision to pursue the internal mammary nodes (IMN) is another source of controversy. METHODS From April 1998 to November 2000, 1,470 patients underwent lymphatic mapping for breast cancer and were prospectively entered into the breast database. The combined technique method was used, consisting of both isosulfan blue dye and technetium-99 labeled sulfur colloid. Patients with inner quadrant lesions and suspicion for internal mammary metastasis had preoperative lymphoscintigraphy. Those with internal mammary radioactivity noted by either lymphoscintigraphy or gamma probe underwent removal of the internal mammary sentinel nodes. RESULTS Thirty-six of the 1,470 (2.4%) patients mapped had at least 1 internal mammary lymph node removed. Inner quadrant lesions were present in 24 of the 36 (67%) IMN mapped patients. Of the 36 patients mapping to the IM area, 5 (14%) had at least 1 IM node positive. Two of the 5 (40%) had only IM metastasis, with 1 of these patients having 5 of 5 IMN positive and no disease detected in her axilla. A total of 2 of the 5 (40%) IM positive patients had more than 1 IMN positive. Twenty-eight of the 36 (78%) IM node harvested patients had preoperative lymphoscintigraphy, with 18 (64%) IMN appearing on imaging. Complications occurred in 3 of the 36 (8%) IMN mapped patients, without clinical significance. CONCLUSIONS Mapping to the IMN basin with the finding of metastasis results in N3 disease by the current staging system. The consequence for these patients is radiation therapy to the IMN basin. It is significant to note that 14% (5 of 36) were upstaged as result of IMN detection and 40% (2 of 5) had multiple positive IMNs. Substantial disease was detected in these 5 patients necessitating additional radiation therapy while avoiding IM radiation and its attendant complications in 86% of patients mapping to the IM basin.
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Gray RJ, Salud C, Nguyen K, Dauway E, Friedland J, Berman C, Peltz E, Whitehead G, Cox CE. Randomized prospective evaluation of a novel technique for biopsy or lumpectomy of nonpalpable breast lesions: radioactive seed versus wire localization. Ann Surg Oncol 2001; 8:711-5. [PMID: 11597011 DOI: 10.1007/s10434-001-0711-3] [Citation(s) in RCA: 217] [Impact Index Per Article: 9.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
Abstract
BACKGROUND Standard wire localization (WL) and excision of nonpalpable breast lesions has several shortcomings. METHODS Ninety-seven women with nonpalpable breast lesions were prospectively randomized to radioactive seed localization (RSL) or WL. For RSL, a titanium seed containing 125I was placed at the site of the lesion by using radiographical guidance. The surgeon used a handheld gamma detector to locate and excise the seed and lesion. RESULTS Both techniques resulted in 100% retrieval of the lesions. Fewer RSL patients required resection of additional margins than WL patients (26% vs. 57%, respectively, P = .02). There were no significant differences in mean times for operative excision (5.4 vs. 6.1 minutes) or radiographical localization (13.9 vs. 13.2 minutes). There were also no significant differences in the subjective ease of the procedures as rated by surgeons, radiologists, and patients. All WLs were carried out on the same day as the excision, whereas RSL was performed up to 5 days before the operative procedure. CONCLUSIONS RSL is as effective as WL for the excision of nonpalpable breast lesions and reduces the incidence of pathologically involved margins of excision. RSL also reduces scheduling conflicts and may allow elimination of intraoperative specimen mammography. RSL is an attractive alternative to WL.
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Miguel R, Kuhn AM, Shons AR, Dyches P, Ebert MD, Peltz ES, Nguyen K, Cox CE. The effect of sentinel node selective axillary lymphadenectomy on the incidence of postmastectomy pain syndrome. Cancer Control 2001; 8:427-30. [PMID: 11579339 DOI: 10.1177/107327480100800506] [Citation(s) in RCA: 42] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
Abstract
BACKGROUND Postmastectomy pain syndrome (PMPS) has been reported following procedures involving complete lymph node dissection (CLND). Since the triggering event is probably related to nerve injury, sentinel lymph node dissection (SLND) should decrease the incidence of PMPS. The purpose of this report is to determine the impact of SLND on the number of patients referred to the pain clinic for PMPS treatment. METHODS The records of all breast surgical patients with a diagnosis of PMPS referred to the Moffitt Cancer Center pain clinic were reviewed. The criterion for diagnosis of PMPS was a history of postoperative pain in the upper anterior chest wall, upper extremity, axilla, and/or shoulder in the absence of recurrent disease. RESULTS A total of 55 patients with a diagnosis of PMPS were seen in the pain clinic since 1991. Treatments included local anesthetics/corticosteroid injection, stellate ganglion block, and tricyclic antidepressants. A decrease from 15 patients in 1991 to 3 in 1998 was observed. All but one of the 55 patients with PMPS had CLND, and none referred to the pain clinic had undergone SLND. CONCLUSIONS PMPS is a complication of CLND. The increased use of SLND in our center has reduced the number of referrals to the pain clinic for treatment of PMPS. This benefit of SLND reduces suffering in the postoperative breast patient.
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Roberts LW, Geppert C, Connor R, Nguyen K, Warner TD. An invitation for medical educators to focus on ethical and policy issues in research and scholarly practice. ACADEMIC MEDICINE : JOURNAL OF THE ASSOCIATION OF AMERICAN MEDICAL COLLEGES 2001; 76:876-885. [PMID: 11553501 DOI: 10.1097/00001888-200109000-00007] [Citation(s) in RCA: 20] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
Medical education research and medical education practice both involve being methodical, innovative, self-observing, forward-looking, and open to peer review, and both are scholarly activities. For these reasons, distinguishing between these two activities is often difficult. There are three important reasons to clarify the distinctions: the moral difference between education research and education practice; federal regulations governing education research that require more safeguards than often exist in education practice; and the fact that student participants in research have characteristics in common with members of special populations. The authors explain why attention to issues of safeguards in education research and practice is likely to grow at academic health centers, yet maintain that these issues are neglected in the medical education literature. They demonstrate this with findings from their review of 424 education research reports published in 1988 and 1989 and in 1998 and 1999 in two major medical education journals. Each article was evaluated for documentation of six ethically important safeguards and features (e.g., informed consent). The rates of reporting the six features and safeguards were relatively low (3-27%). Nearly half (47%) of the empirical reports offered no indication of ethically important safeguards or features, and no article mentioned all six. Furthermore, those rates did not increase substantially after ten years. The authors discuss a number of implications of their findings for faculty, training institutions, students, and editors and peer reviewers, and conclude with the hope that their findings will raise awareness of these neglected issues in medical education and will stimulate all those involved to reflect upon the issues and set standards on the ethical aspects of research and scholarly practice.
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Christensen GE, Carlson B, Chao KS, Yin P, Grigsby PW, Nguyen K, Dempsey JF, Lerma FA, Bae KT, Vannier MW, Williamson JF. Image-based dose planning of intracavitary brachytherapy: registration of serial-imaging studies using deformable anatomic templates. Int J Radiat Oncol Biol Phys 2001; 51:227-43. [PMID: 11516873 DOI: 10.1016/s0360-3016(01)01667-4] [Citation(s) in RCA: 84] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
PURPOSE To demonstrate that high-dimensional voxel-to-voxel transformations, derived from continuum mechanics models of the underlying pelvic tissues, can be used to register computed tomography (CT) serial examinations into a single anatomic frame of reference for cumulative dose calculations. METHODS AND MATERIALS Three patients with locally advanced cervix cancer were treated with CT-compatible intracavitary (ICT) applicators. Each patient underwent five volumetric CT examinations: before initiating treatment, and immediately before and after the first and second ICT insertions, respectively. Each serial examination was rigidly registered to the patient's first ICT examination by aligning the bony anatomy. Detailed nonrigid alignment for organs (or targets) of interest was subsequently achieved by deforming the CT exams as a viscous-fluid, described by the Navier-Stokes equation, until the coincidence with the corresponding targets on CT image was maximized. In cases where ICT insertion induced very large and topologically complex rearrangements of pelvic organs, e.g., extreme uterine canal reorientation following tandem insertion, a viscous-fluid-landmark transformation was used to produce an initial registration. RESULTS For all three patients, reasonable registrations for organs (or targets) of interest were achieved. Fluid-landmark initialization was required in 4 of the 11 registrations. Relative to the best rigid bony landmark alignment, the viscous-fluid registration resulted in average soft-tissue displacements from 2.8 to 28.1 mm, and improved organ coincidence from the range of 5.2% to 72.2% to the range of 90.6% to 100%. Compared to the viscous-fluid transformation, global registration of bony anatomy mismatched 5% or more of the contoured organ volumes by 15-25 mm. CONCLUSION Pelvic soft-tissue structures undergo large deformations and displacements during the external-beam and multiple-ICT course of radiation therapy for locally advanced cervix cancer. These changes cannot be modeled by the conventional rigid landmark transformation method. In the current study, we found that the deformable anatomic template registration method, based on continuum-mechanics models of deformation, successfully described these large anatomic shape changes before and after ICT. These promising modeling results indicate that realistic registration of the cumulative dose distribution to the organs (or targets) of interest for radiation therapy of cervical cancers is achievable.
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Brandes RP, Viedt C, Nguyen K, Beer S, Kreuzer J, Busse R, Görlach A. Thrombin-induced MCP-1 expression involves activation of the p22phox-containing NADPH oxidase in human vascular smooth muscle cells. Thromb Haemost 2001; 85:1104-10. [PMID: 11434692] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/20/2023]
Abstract
UNLABELLED Activation of vascular smooth muscle cells (VMSC) by thrombin induces the expression of the chemokine, monocyte chemoattractant protein-1 (MCP-1). We investigated in cultured human and rat VSMC whether reactive oxygen species (ROS) derived from the vascular NADPH oxidase contribute to this effect. Exposure of cultured VSMC to thrombin rapidly increased ROS formation, phosphorylation of p38 MAP kinase as well as the expression of MCP-1. Specific inhibition of the p22phox subunit of the vascular NADPH oxidase using either p22phox neutralizing antibody or p22phox antisense oligonucleotides attenuated thrombin-induced ROS generation. Furthermore, thrombin-induced p38 MAP kinase activation as well as MCP-1 expression were impaired by antioxidants as well as by p22phox antisense oligonucleotides. Inhibition of p38 MAP kinase diminished the thrombin-induced expression of MCP-1. CONCLUSION Thrombin, by activating a p22phox-containing NADPH oxidase, elicits ROS generation and activation of p38 MAP kinase in VSMC. The subsequent induction of MCP-1 expression highligts the crucial role of the p22phox-containing NADPH oxidase in thrombin-induced signal transduction in VSMC.
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MESH Headings
- Animals
- Aorta/cytology
- Cell Culture Techniques
- Chemokine CCL2/metabolism
- Dose-Response Relationship, Drug
- Enzyme Activation/drug effects
- Humans
- Kinetics
- MAP Kinase Signaling System/drug effects
- Male
- Membrane Transport Proteins
- Muscle, Smooth, Vascular/cytology
- Muscle, Smooth, Vascular/drug effects
- Muscle, Smooth, Vascular/enzymology
- Muscle, Smooth, Vascular/metabolism
- NADPH Dehydrogenase
- NADPH Oxidases/chemistry
- NADPH Oxidases/metabolism
- NADPH Oxidases/pharmacology
- Phosphoproteins
- Rats
- Rats, Wistar
- Reactive Oxygen Species/metabolism
- Thrombin/pharmacology
- Thrombin/physiology
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Goluszko P, Selvarangan R, Nowicki BJ, Nowicki S, Hart A, Pawelczyk E, Nguyen K. Rapid receptor-clustering assay to detect uropathogenic and diarrheal Escherichia coli isolates bearing adhesins of the Dr family. J Clin Microbiol 2001; 39:2317-20. [PMID: 11376081 PMCID: PMC88135 DOI: 10.1128/jcm.39.6.2317-2320.2001] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2000] [Accepted: 03/11/2001] [Indexed: 11/20/2022] Open
Abstract
Infections caused by Escherichia coli isolates expressing adhesins of the Dr family are associated with diarrhea and urinary tract infections, and these E. coli strains recognize the complement regulatory protein decay-accelerating factor (DAF) as their receptor. Clustering of the DAF receptor at the sites of bacterial adherence to epithelial cells is proposed as an alternative to PCR assay for rapid detection of Dr-positive E. coli.
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Hopper CA, Gruber MB, Munoz KD, MacConnie SE, Pfingston YM, Nguyen K. Relationship of blood cholesterol to body composition, physical fitness, and dietary intake measures in third-grade children and their parents. RESEARCH QUARTERLY FOR EXERCISE AND SPORT 2001; 72:182-188. [PMID: 11393881 DOI: 10.1080/02701367.2001.10608948] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
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Cox CE, Nguyen K, Gray RJ, Salud C, Ku NN, Dupont E, Hutson L, Peltz E, Whitehead G, Reintgen D, Cantor A. Importance of lymphatic mapping in ductal carcinoma in situ (DCIS): why map DCIS? Am Surg 2001; 67:513-9; discussion 519-21. [PMID: 11409797] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/20/2023]
Abstract
The appropriateness of sentinel lymph node biopsy in the management of patients with biopsy diagnoses of ductal carcinoma in situ (DCIS) or DCIS with microinvasion (DCISM) has not been established. Three hundred forty-one patients presented with a biopsy diagnosis of DCIS or DCISM. Two hundred forty (70%) underwent sentinel node biopsy at their definitive procedure. All clinical and pathologic data were collected prospectively. Of 224 patients with a biopsy diagnosis of DCIS 23 (10%) were upstaged to infiltrating ductal carcinoma (IDC) at their definitive therapy and of 16 patients with a biopsy diagnosis of DCISM seven (44%) were upstaged to IDC. Excisional biopsies were no more sensitive for detecting IDC than was core biopsy. Lymph node metastases were detected in 26 of 195 (13%) patients with a definitive diagnosis of DCIS, in three of 15 (20%) with a definitive diagnosis of DCISM, and in eight of 30 (27%) with a definitive diagnosis of IDC. Sentinel lymph node biopsy is a valuable tool in the treatment of patients with DCIS and DCISM and is particularly needed in those undergoing mastectomy. No "high-risk" group of patients can be identified for selective sentinel lymph node biopsy.
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Franz MG, Kuhn MA, Nguyen K, Wang X, Ko F, Wright TE, Robson MC. Transforming growth factor beta(2) lowers the incidence of incisional hernias. J Surg Res 2001; 97:109-16. [PMID: 11341785 DOI: 10.1006/jsre.2001.6083] [Citation(s) in RCA: 43] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
BACKGROUND Approximately 200,000 incisional hernias are repaired annually in the United States. The high incidence (11-20%) and recurrence rate (24-54%) for incisional hernias have not changed appreciably in 75 years. Mechanical advances in suture material, incision orientation, and closure technique have failed to eliminate this common surgical complication. A biological approach to acute wound failure may offer a new strategy. METHODS A rodent incisional hernia model was used. Seventy rats underwent 5-cm midline celiotomies and were closed with fine, fast-absorbing sutures to induce intentional acute wound failure. Group 1 received no other treatment. The midline fascia in groups 2 and 3 was injected immediately prior to incision with 100 microl of vehicle alone or vehicle containing 1 microg of transforming growth factor beta(2) (TGF-beta(2)). Necropsy was performed on Postoperative Day 28 and the wounds were examined for herniation. RESULTS Incisional hernias developed in 88% (35/40) and 79% (11/14) of untreated incisions and those treated with vehicle alone. No hernias formed in the TGF-beta(2)-treated incisions (0/16, P < 0.05). Standard histology and immunohistochemistry demonstrated enhanced macrophage, lymphocyte, and fibroblast chemotaxis and increased collagen I and III production in TGF-beta(2) treated incisions. CONCLUSIONS Treatment of abdominal wall fascial incisions with TGF-beta(2) prevented the development of incisional hernias in this rat model. TGF-beta(2) stimulated fascial macrophage and fibroblast chemotaxis as well as acute wound collagen production. A biological approach such as this may reduce the incidence of incisional hernia formation in humans.
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Dupont E, Cox C, Shivers S, Salud C, Nguyen K, Cantor A, Reintgen D. Learning curves and breast cancer lymphatic mapping: institutional volume index. J Surg Res 2001; 97:92-6. [PMID: 11319887 DOI: 10.1006/jsre.2001.6127] [Citation(s) in RCA: 37] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
INTRODUCTION To date, studies of breast cancer lymphatic mapping (LM) have analyzed success with respect to individual surgeons. However, LM and sentinel lymph node biopsy (SLNBx) are procedures that require institutional multidisciplinary cooperation between the departments of radiology, pathology, and surgery. Thus, it is important to evaluate these procedures with respect to the institution. This study examines 30 institutions to clarify the value of the institutional volume index (IVI) (cases/month) to the outcome of LM and SLNBx in breast cancer. METHODS From July 1997 to July 1999, 30 institutions participated in the Department of Defense national breast LM trial. All participants underwent a 2-day training course for surgeons, nuclear medicine physicians, and pathologists. The records for each institution were prospectively accrued and submitted to a database. The false negatives, failure rates, and IVI were calculated for each institution. A logistic regression model plots the relationship between IVI and institutional failure rate. Using a multivariate analysis, mapping failure was analyzed as a function of case number with respect to the individual surgeon and the institution as a whole. RESULTS False negative results were demonstrated in only 5 (4%) cases among all institutions and were excluded from further analysis due to small numbers. Mapping failures were found in all but 7 of the 30 institutions whose data were complete. There were 71 mapping failures among 74 surgeons over 555 cases, which yielded an overall failure rate of 12.79% (71 555). The logistic regression model revealed an inverse relationship between IVI and institutional failure rate. However, the multivariate analysis revealed that the individual surgeon performance was the most significant factor in determining institutional mapping success. CONCLUSION Failure to map can be a function of multiple factors including surgical skill, surgical volume index, and injection method of the SLN patient, all under the quality control of an institution. The surgical failure rate on the other hand is a function of surgical skill, surgical volume, and injection methods. While differences in mapping success exist across institutions, this disparity is not due to factors associated with the institution as a whole, but lie with the individual surgeon.
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Doughty L, Nguyen K, Durbin J, Biron C. A role for IFN-alpha beta in virus infection-induced sensitization to endotoxin. JOURNAL OF IMMUNOLOGY (BALTIMORE, MD. : 1950) 2001; 166:2658-64. [PMID: 11160329 DOI: 10.4049/jimmunol.166.4.2658] [Citation(s) in RCA: 68] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Underlying viral infections can heighten sensitivity and worsen cytokine-mediated disease following secondary inflammatory challenges. Mechanisms for this are poorly understood. The impact of the innate response to lymphocytic choriomeningitis virus (LCMV) infection on sensitivity to endotoxin (LPS) was investigated. Compared with uninfected mice, infection with LCMV for 2-days-sensitized mice to LPS by approximately 2-fold for lethality and by 2- to 6-fold for serum TNF-alpha levels. Priming for LPS-induced TNF-alpha was also seen with splenic and peritoneal leukocytes isolated from infected mice and challenged with LPS ex vivo. The effect on TNF-alpha production was present in the absence of IFN-gamma, its major producers NK and T cells, and the major pathways for its induction through IL-12 and the signal transducer and activator of transcription 4 (STAT4), and therefore was IFN-gamma independent. Early LCMV infection induces high concentrations of the type 1 IFNs, IFN-alphabeta. Administration of recombinant IFN-alpha alone heightened the TNF-alpha response to LPS. Innate IFN-alphabeta and IFN-gamma responses to LCMV exist in a delicate balance. To reduce priming for LPS-induced TNF-alpha during LCMV, deficiencies in both the IFN-alphabeta and IFN-gamma receptors or STAT1, a transcription factor downstream to both IFNs, were required. These data demonstrate that early viral infection can enhance sensitivity to bacterial products, and that this sensitization can occur in part as a result of endogenously expressed IFN-alphabeta. This work also raises issues about potential complications associated with IFN-alphabeta therapies.
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Nguyen K, Fink A, Beck JC, Higa J. Feasibility of using an alcohol-screening and health education system with older primary care patients. THE JOURNAL OF THE AMERICAN BOARD OF FAMILY PRACTICE 2001; 14:7-15. [PMID: 11206697] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Subscribe] [Scholar Register] [Indexed: 04/16/2023]
Abstract
BACKGROUND This study evaluated the feasibility of a combined alcohol-screening and health education system for elderly patients METHODS The Computerized Alcohol-Related Problems Survey (CARPS) was evaluated in primary care practices among 106 current drinkers, 60 years and older. The CARPS contains (1) a self-administered screening survey; (2) software to scan or hand-enter survey responses; (3) software to process data and electronically generate reports of patients' drinking risks; (4) health education; and (5) a database useful for clinical and quality improvement purposes. RESULTS Nearly all study participants were able to complete the CARPS while waiting for a prescheduled appointment with their physician. There were 44% of patients who were hazardous and 9% who were harmful drinkers. About 20% of men and 26% of women were binge drinkers. Most (85%) patients agreed that alcohol is an important topic, 67% reported learning new information, 78% had never discussed drinking with a physician, and 31% intended to do so. After reviewing CARPS data, physicians concluded that alcohol use in the elderly is an important quality improvement topic. CONCLUSIONS Combined screening and health education systems appear feasible for use in practice if they deal with pertinent health problems such as alcohol use. Their data can encourage discussions between physicians and patients and might be used for quality improvement activities.
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O'Connor KC, Nguyen K, Stollar BD. Recognition of DNA by VH and Fv domains of an IgG anti-poly(dC) antibody with a singly mutated VH domain. J Mol Recognit 2001; 14:18-28. [PMID: 11180559 DOI: 10.1002/1099-1352(200101/02)14:1<18::aid-jmr515>3.0.co;2-2] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
Secondary antigen stimulation usually produces IgG antibodies with hypermutated V segments. Studying a strong secondary response to the polynucleotide antigen poly(dC), however, we found a highly selective IgG antibody (mAb dC7) with only one mutation (a conservative Leu to Ileu substitution) throughout the whole VH domain. To investigate the roles of VH and VL domains in selective binding by this mAb, we prepared its VH, VL and single-chain Fv (scFv) fragments. A bacterial expression system produced soluble monomeric V region proteins. CD spectra confirmed that they had the beta-secondary structure expected for Ig domains. Both the scFv and VH fragments bound to single-stranded non-protonated poly(dC) and to ssDNA but not to protonated, more structured poly(dC) or dsDNA. The VL domain alone did not bind to nucleic acids, but VL association modified the VH binding, giving the scFv a 10-fold higher affinity than the VH for poly(dC) and greatly increasing the cytosine-dependent selectivity. Non-ionic interactions were prominent in the Fv reaction with a (dC)( n) sequence. Ionic interactions were revealed in Fv cross-reactions with ssDNA, and were more prominent in binding of either poly(dC) or ssDNA by VH alone, consistent with the lesser base selectivity of the VH. Thus, the Fv and VH alone bind to a single antigen, poly(dC), but mechanistic differences result from additional subsites in the Fv. Generation of a selective IgG with very few CDR mutations in either VH or VL, which was accompanied by IgM antibodies with unmutated V regions, also suggests that nucleic acid binding activity is a property of the B cell repertoire even before immunization.
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Iyer M, Barrio JR, Namavari M, Bauer E, Satyamurthy N, Nguyen K, Toyokuni T, Phelps ME, Herschman HR, Gambhir SS. 8-[18F]Fluoropenciclovir: an improved reporter probe for imaging HSV1-tk reporter gene expression in vivo using PET. J Nucl Med 2001; 42:96-105. [PMID: 11197989] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/19/2023] Open
Abstract
UNLABELLED We have synthesized and evaluated 8-[18F]fluoropenciclovir (FPCV) and compared it with 8-[18F]fluoroganciclovir (FGCV) for monitoring the expression of herpes simplex virus type 1 thymidine kinase (HSV1 -tk) reporter gene in cell culture and in vivo. METHODS C6 rat glioma cells stably transfected with HSV1-tk (C6-stb-tk+) and control C6 cells were evaluated for their ability to accumulate FGCV versus FPCV. For in vivo studies, 15 mice were injected by tail vein with increasing levels of an adenoviral vector carrying HSV1-tk. Forty-eight hours later the mice were injected with FPCV and killed 3 h later. The percentage injected dose per gram (%ID/g) liver was then determined. Two additional mice were studied by microPET and autoradiography using FPCV to image adenoviral-mediated hepatic HSV1-tk reporter gene expression. A tumor-bearing mouse (C6 control and C6-stb-tk+) was imaged with FDG, FGCV, and FPCV. Two mice carrying tumors expressing two different reporter genes, HSV1-tk and dopamine type 2 receptor (D2R), were also imaged by microPET using FPCV (day 1) and 3-(2'-[18F]fluoroethyl)spiperone (FESP) (day 2). RESULTS FPCV shows a significantly greater accumulation in C6-stb-tk+ cells than does FGCV (P < 0.05). Over identical ranges of adenoviral administration, mouse liver shows a higher %ID/g liver for FPCV (0%-9%) compared with our previously reported results with FGCV (0%-3%). In C6 control and C6-stb-tk+ tumor-bearing mice, FPCV has a greater accumulation than does FGCV for equal levels of HSV1-tk gene expression. In mice carrying tumors expressing either HSV1-tk or D2R reporter genes, there is a corresponding retention of FPCV and FESP, respectively. CONCLUSION These results indicate that FPCV is a better reporter probe than is FGCV for imaging lower levels of HSV1 -tk gene expression in vivo. The results also reveal the ability to monitor the expression of two distinct reporter genes in the same animal using reporter probes specific for each gene.
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