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D N'Guyen

Publications and source records attributed to D N'Guyen.

6 recordsLinked to original sources
PubMed2003

[Interest of the cervical gland dissection after radiotherapy with or without chemotherapy].

OBJECTIVES: The aim of this study was to evaluate the necessity and morbidity of neck dissection after radiation therapy within organ preservation treatment. PATIENTS AND METHODS: We present a retrospective study of 64 patients, treated initially by radiotherapy with or without chemotherapy for squamous cell carcinoma of head and neck with cervical metastases (> 2 cm), who underwent post-radiation neck dissection between January 1992 and August 2000. Eight (13%) patients were classified T1, nineteen (30%) T2, twenty (31%) T3, eleven (17%) T4 and six (9%) Tx. Eleven patients had N1 neck disease (17%), fifteen patients N2a (24%), eleven patients N2b (17%) and twenty-seven patients N3 (42%). RESULTS: Follow-up ranged from 3 to 86 months with a mean of 39 months. The average length of time between neck dissection and the end of treatment was 60 days. Complications were recorded in 21 patients (33%). Forty-four (68%) of 64 patients had microscopic residual disease. Eight (72%) of 11 patients with N1 neck disease and 17 (63%) of 27 patients with N3 neck disease had pathology. Initial N status was not a predictive factor of microscopic residual disease (p = 0.51). There was no significant relationship between clinical residual adenopathy and microscopic residual disease (p = 0.53). Fourteen patients are still alive without recurrent disease. Eight (57%) of these 14 patients had a positive pathology at the time of neck dissection. The mean follow-up time of these patients is 32.6 months, with a follow up longer than 2 years for half of them (n = 7). CONCLUSION: Neck dissection after radiation was planned for all patients with an initial node > 2 cm in diameter regardless of clinical response in the neck. We confirm that neck dissection appears to be safe after radiotherapy and is necessary because it improves quality of life and prevents fatal evolution with uncontrollable neck disease.

Adult↗
PubMed1998

Importance of central alpha-helices of human apolipoprotein A-I in the maturation of high-density lipoproteins.

We have studied the role of amphipathic alpha-helices in the ability of apoA-I to promote cholesterol efflux from human skin fibroblasts and activate lecithin:cholesterol acyltransferase (LCAT). Three apoA-I mutants were designed, each by deletion of a pair of predicted adjacent central alpha-helices [Delta(100-143), Delta(122-165), Delta(144-186)], and expressed in Escherichia coli. This strategy was used to minimize disruption of the predicted secondary structure of the resulting protein. These three central deletion mutants have been previously shown to be expressed as stable folded proteins but to exhibit altered phospholipid-binding properties. When recombined with phospholipids to form homogeneous LpA-I containing equivalent amounts of POPC and tested for their ability to promote diffusional cholesterol efflux from normal [3H]cholesterol-labeled fibroblasts, each mutant and the wild-type recombinant protein (Rec.-apoA-I) promoted cholesterol efflux with very similar rates at all the concentrations tested. These experiments showed that all LpA-I could acquire cellular cholesterol with similar affinity and binding capacity. However, when the cell-incubated LpA-I were incubated with purified LCAT, two mutants, Delta(122-165) and Delta(144-186), appeared incapable of activating the enzyme. To directly determine their ability to activate LCAT, each mutant and the control were recombined with equivalent amounts of cholesterol and phospholipid and incubated with the purified enzyme. The results show that whereas deletion of residues 100-143 has little effect on LCAT activation, deletion of residues 122-165 or 144-186 results in an inability of the mutants to promote cholesterol esterification. In conclusion, our results show that no specific sequence in the central domain of apoA-I is required for efficient diffusional cholesterol efflux from normal fibroblasts; however, residues 144-186 appear critical for optimum LCAT activation and cholesteryl ester accumulation. Since deletion of residues 144-186 also perturbs phospholipid association and prevents the formation of large LpA-I particles [Frank, P. G., Bergeron, J., Emmanuel, F., Lavigne, J. P., Sparks, D. L., Denèfle, P., Rassart, E., and Marcel, Y. L. (1997) Biochemistry 36, 1798-1806], the data show that this pair of alpha-helices plays an important role in the maturation of HDL. Sequence analysis of these apoA-I helices further identifies specific residues that appear essential to this activity.

Amino Acid Sequence↗
PubMed1997

[Drug-induced stenosis of the small bowel. Value of enteroclysis].

The purpose of this study is to characterize radiographically drug-induced ulcerated stenosis of the small bowel and to determine the contribution of enteroclysis in the diagnosis of this rare entity. The clinical pathologic and radiographic findings of 12 patients with drug-induced stenosis (non steroidal anti-inflammatory drugs or potassium salts) evaluated by enteroclysis were reviewed. Three radiological features of strictures were differentiated: diaphragm like stricture, short stricture and stenotic ulceration with girdle aspect. All formulation of NSAIDS and potassium salts are capable of causing the same radiographic and pathologic patterns. Enteroclysis improves the detection of these lesions since intestinal overdistension and correct filling of the loops increase the visualization of small obstructive stenosis and the detection of superficial ulcers. Thus, any patient who has an abnormality of the small bowel should be asked about use of drugs, especially when diaphragm-like strictures are found.

Aged↗
PubMed1997

[Hormonal suppressive therapy of thyroid nodules].

We studied 426 patients in order to analyse the effectiveness of levothyroxine in treating patients with cold thyroid nodules. Nodule volume ranged initially from 0.1 to 10 mL and was measured over a 3 to 18 month-period of treatment using ultrasonography. Nodule variation was studied in each case according to levels of TSH and others factors (age, sex, familial thyroid history, initial volume of nodule and of thyroid gland, date of diagnosis, ultrasonic findings, duration of treatment). Nodule volume increased in 32.6% and significantly decreased (> 50%) in 35.8%. In 2.8% the nodule disappeared. No correlation was found between variation of thyroid nodules and TSH levels under treatment. Similarly no relationship was found between volume variation and other criteria. These results suggest that TSH suppressing doses of levothyroxine are of no advantage in reducing the volume of cold thyroid nodules compared to lower doses.

Adolescent↗
PubMedDate not supplied

[Prostatic brachytherapy: an alternative therapy. Review of the literature] .

Radical prostatectomy remains the 'golden standard' therapy for localized prostate carcinoma for patients with a survival rate of more than ten years. However, because of the complications inherent in this surgical procedure, prostatectomy is presently increasingly challenged by various radiotherapy procedures. In the last decade, more sophisticated conformal therapy techniques have been proposed for prostate cancer patients. In parallel, for highly selected patients, brachytherapy is being promoted by an increasing number of medical centers. In fact, brachytherapy techniques for prostate cancers can be traced back to 1911, but recently developed techniques offer reliability and reproducibility, with satisfactory results in terms of tumor control and reduced toxicity, in selected patients. We present here the different techniques that are available today in prostate cancer brachytherapy.

Brachytherapy↗