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D Lefebvre

Publications and source records attributed to D Lefebvre.

At least 19 recordsLinked to original sources
PubMed2001

[Anticancer chemotherapy, risk factor for infection at the operated site in cervicofacial surgery].

BACKGROUND: In order to evaluate occurrence and risk factors for wound infection (WI) in head and neck uncontaminated surgery, we carried out a prospective study. METHODS: From january 1997 through january 1999, we prospectively evaluated 212 wounds of all patients having uncontaminated head and neck surgery at the Oscar Lambret Cancer Center (neck dissections, parotidectomies, thyroidectomies, explorative cervicotomies, cutaneous resections). No antibiotic prophylaxis was given. WI was defined as a wound with pus. Statistical evaluation was performed using the chi 2 test. In univariate analysis, differences were considered significant p < 0.05. RESULTS: The overall WI rate was 6.6% (14/212). In univariate analysis, previous chemotherapy is the only risk factor for WI were: (p < 0.00001). Multivariate analysis was not performed. CONCLUSION: Like other cancer locations, chemotherapy was a major risk factor for WI. In these cases, a phase ill trial could confirm efficacy of standard antibiotic.

Adult↗
PubMed2001

Risk factors for wound infection in head and neck cancer surgery: a prospective study.

BACKGROUND: The goal of this prospective study is to determine risk factors for wound infections (WI) for patients with head and neck cancer who underwent surgical procedure with opening of upper aerodigestive tract mucosa. METHODS: One hundred sixty-five consecutive surgical procedures were studied at Oscar Lambret Cancer Center within a 24-month interval. Twenty-five variables were recorded for each patient. Statistical evaluation used Chi2 test analysis (categorical data) and Mann-Whitney test (continuous variables). RESULTS: The overall rate of WI was 41.8%. Univariate analysis indicated that five variables were significantly related to the likelihood of WI: tumor stage (p =.044), previous chemotherapy (p =.008), duration of preoperative hospital stay (p = 022), permanent tracheostomy (p =.00008), and hypopharyngeal and laryngeal cancers (p =.008). CONCLUSIONS: Despite antibiotic prophylaxis, WI occurrence is high. These data inform the head and neck surgeon, when a patient is at risk for WI and may help to design future prospective studies.

Adult↗
PubMed2001

Mutations in LIKE HETEROCHROMATIN PROTEIN 1 affect flowering time and plant architecture in Arabidopsis.

In plants, recent studies have demonstrated links between the regulation of developmental processes and chromatin dynamics and organisation. Analysis of new mutations affecting overall plant architecture, leaf development and flowering time in Arabidopsis has allowed us to clone and characterise LHP1, the Drosophila heterochromatin protein 1 (HP1) homologue. LHP1 has the chromo and chromo shadow domains central to the function of animal proteins. Yeast two hybrid studies and in planta deletion experiments suggest similar modes of action in plants and animals via homodimer formation. In vivo localisation experiments revealed a specific subnuclear protein distribution in foci throughout the nucleus. Our data suggest that LHP1 may act as a main regulator of gene expression in plants, through formation of heterochromatin-like repressive complexes, to control developmental pathways involved in organ and cell size, and the vegetative to reproductive phase transition.

Amino Acid Sequence↗
PubMed2001

A case-acquisition and decision-support system for the analysis of group-average lactation curves.

A case-acquisition and decision-support system was developed to support the analysis of group-average lactation curves and to acquire example cases from domain specialists. This software was developed through several iterations of a three-step approach involving 1) problem analysis and formulation in consultation with two dairy nutrition specialists; 2) development of a case-acquisition and decision-support prototype by the system developer; and 3) use of the prototype by the domain specialists to analyze and classify milk-recording data from example herds. The overall problem was decomposed into three subproblems: removal of outlier tests and lactation curves of individual cows; interpretation of group-average lactation curves; and diagnosis of detected abnormalities at the herd level through the identification of potential management deficiencies. For each subproblem, a software module was developed allowing the user to analyze both graphical and numerical performance representations and classify these representations using predefined linguistic descriptors. The example-based method for the development of the program proved to be very useful, facilitating the communication between system developer and domain specialists, and allowing the specialists to explore the appropriateness of the various prototypes developed. The resulting software represents a formalization of the approach to group-average lactation curve analysis, elicited from the two domain specialists. In future research, the case-acquisition and decision-support system will be complemented with knowledge to automate identified classification tasks, which will be captured through the application of machine-learning techniques to example cases, acquired from domain specialists using the software.

Animals↗
PubMed2000

[Incidence and surgical wound infection risk factors in breast cancer surgery].

BACKGROUND: In order to evaluate occurrence and risk factors for wound infection (WI) in breast cancer surgery, we carried out a prospective study. METHODS: From September 1996 through April 1997, an infection control physician prospectively evaluated 542 wounds of all patients having breast cancer surgery at the Oscar Lambret Cancer Center. WI was defined as a wound with pus. Antibiotic prophylaxis was given in case of immediate breast reconstruction. Statistical evaluation was performed using the c < or = test for categorial data and non-parametric Mann-Whitney test for continuous data. In univariate analysis, differences were considered significant at p < 0.01. RESULTS: The overall WI rate was 3.51% (19/352). In univariate analysis, risk factors for WI were: total preoperative hospital stay (p = 0.01), previous chemotherapy (p = 0.01), previous oncologic surgery (p = 0.03) and immediate breast reconstruction (p = 0.002). In mutivariate analysis, we observed two independent predictive factors for WI: previous chemotherapy (p = 0.05) and immediate breast reconstruction (p = 0.02). CONCLUSIONS: Previous anticancer chemotherapy was a major risk factor. In these cases, a phase III trial could confirm efficacy of standard antibiotic prophylaxis. Breast reconstruction was the second major risk factor. Standard antibiotic prophylaxis (used in our study) was insufficient.

Adolescent↗
PubMed1999

Inhibition of insulin-like growth factor-I mitogenic action by zinc chelation is associated with a decreased mitogen-activated protein kinase activation in RAT-1 fibroblasts.

The mechanisms responsible for the resistance to the anabolic actions of IGF-I induced by zinc deficiency are not understood. We showed that zinc chelation by DTPA (diethylenetriaminepenta-acetic acid) inhibits [3H]thymidine incorporation stimulated by IGF-I in Rat-1 fibroblasts. This inhibition was specific of zinc chelation since it was prevented by the addition of zinc to DTPA. The stimulation of MAPK, which is crucial for the [3H]thymidine incorporation induced by IGF-I in Rat-1 cells, was partially blunted by DTPA. Therefore, the inhibition of the mitogenic action of IGF-I in Rat-1 fibroblasts by DTPA is potentially caused by decreased MAPK activation by IGF-I.

Animals↗
PubMed1999

Contribution to the study of the venous vasculature of the penis.

The penile veins are thought to be responsible for some erectile disorders. The aim of this study was to describe the anatomy and function of these veins. The venous systems of 25 cadaveric penises were studied by various anatomic and histologic techniques. The superficial veins arising from the tegumentary layers drain into the superficial dorsal vein which in three-quarters of cases empties into the left great saphenous vein. The veins of the deep internal system, running below the deep fascia of the penis, emerge from the erectile bodies and can be divided into two systems, one anterosuperior and the other posteroinferior. The anterosuperior system comprises the veins of the glans which will form the deep dorsal vein; the latter receives blood from the medial portion of the corpus spongiosum and from the free portion of the corpora cavernosum mainly via the circumflex veins. It ends in the pre-prostatic plexus. The posteroinferior system, issuing from the posterior portion of the erectile bodies, is composed of the bulbar, cavernous and crural veins which drain towards the pre-prostatic plexus and the internal pudendal veins. Anastomoses link the two networks, superficial and deep. Study of the structure of the veins of the deep system reveals the presence of muscular cushions, which we have shown to have adrenergic innervation. These findings are compared with those of the literature, which show variations which are mainly of number. The place of veins in the mechanism of erection is discussed.

Adult↗
PubMed1999

Preoperative small-dose ketamine has no preemptive analgesic effect in patients undergoing total mastectomy.

UNLABELLED: We evaluated the preemptive analgesic effect of a small dose of ketamine given before or immediately after surgery in a randomized, double-blinded study performed in 128 women undergoing total mastectomy. Group 1 patients received ketamine 0.15 mg/kg as a 5-mL i.v. injection 5 min before surgery and isotonic saline 5 mL i.v. at the time of skin closure. Group 2 received 5 mL i.v. of isotonic saline, then 0.15 mg/kg i.v. ketamine. A standard general anesthesia procedure including sufentanil was used. In the recovery room, patient-controlled analgesia i.v. morphine was used for postoperative analgesia. Postoperative pain was assessed by measuring morphine consumption and visual analog scale pain scores. No significant intergroup differences were seen in the pain scores. Patient-controlled analgesia morphine consumption was lower during the first 2 h after surgery in patients given ketamine at the time of skin closure. No patient complained of hallucinations or nightmares. The incidence of adverse effects was not different between the two groups. In conclusion, administering ketamine at the end of surgery is more effective in reducing morphine consumption than it is when given before surgery. IMPLICATIONS: We administered the same small dose of ketamine before or after surgery. The preoperative administration of 0.15 mg/kg ketamine in patients undergoing total mastectomy did not elicit a preemptive analgesic effect. Ketamine given at closure reduced the patient-controlled analgesia morphine requirement in the first 2 h after surgery.

Analgesia, Patient-Controlled↗
PubMed1999

Comparative of blood flow to the ankle-brachial index after iliac angioplasty.

BACKGROUND: Interest of blood flow and ankle brachial pressure index (ABPI) to evaluate result of iliac angioplasty. METHODS: ABPI and blood flow rates were measured before and after angioplasty in 22 lower extremities of 16 patients with iliac stenosis. Blood flow rates were determined by means of a nuclear magnetic resonance (NMR) flow meter. RESULTS: The day after angioplasty, flow and pressure were increasing significantly, whereas a month later, only blood flow was increasing significantly. In a group of patients with near-normal ABPI before angioplasty (ABPI > or = 0.8), there was, on the day following the angioplasty, a significant increase in ABPI and pulsatile blood flow rates; flow rates increased considerably a month after the operation whereas ABPI stay stable. In a group of patients with clearly abnormal ABPI before angioplasty (ABPI <0.80), there was a significant increase in ABPI and blood flow rates the day after angioplasty and again a month later. CONCLUSIONS: Flow therefore seems to vary independently of pressure. The possible use of flow measurement to detect restenoses is yet to be studied.

Adult↗
PubMed1999

[Wound infection in head and neck cancer surgery].

Wound infections (WIs) are the main cause of post-surgical morbidity in head and neck surgery. They arise with an especially immunocompromised predisposition and mainly involve oropharyngeal flora bacteria. However, the assessment of the incidence of these infections differs in the literature (0 to 87%). This in part accounts for the lack of a real consensus as to the definition (do all mucocutaneous fistulae attest to WIs?). For this reason, the analysis of their risk factors and the means of the prevention is difficult. In class 1 surgery, the incidence of WIs ranges 0 to 6%. In this case, antiobioprophylaxis does not seem to be justified. In surgery opening the mucosa, it is difficult to classify the surgical procedures in Altemeier's classes 2 and 3. There are many arguments, in particular physiopathological arguments, to consider that the contamination of surgical bed of surgery does continue after the operation. The incidence of WIs varies widely from one study to the next. Without antibiotic prophylaxis, from 40 to 87% WIs are observed. With preventive antibiotherapy, the incidence ranges between 3.4 to 47%. Various risk factors have been described, in particular: tumour size and node extension, tracheotomy prior to surgery. Four multi-factor studies have shown, in multivariate analysis, totally different risk factors. The prevention of these WIs is currently based on hospital hygiene rules and antibiotic prophylaxis. The optimum conditions have still not been determined. Reliable data to define, the incidence and risk factors of these WIs are missing. New prospective studies are definitely required.

Antibiotic Prophylaxis↗
PubMed1998

Zinc regulation of insulin-like growth factor-I (IGF-I), growth hormone receptor (GHR) and binding protein (GHBP) gene expression in rat cultured hepatocytes.

Dietary zinc depletion in vivo attenuates growth, decreases circulating insulin-like growth factor-I (IGF-I) and liver growth hormone (GH) receptors (GHR). In order to investigate a direct role of zinc in the regulation of IGF-I, GHR and GH binding protein (GHBP) gene expression, we evaluated the response of their mRNAs to changes in zinc availability in primary culture of rat hepatocytes. Exposition of cells to the zinc chelator DTPA (diethylenetriaminepenta-acetic acid) did not decrease IGF-I and GHBP mRNAs while it strongly inhibited metallothionein (MT) gene expression. On the other hand, zinc excess (50 vs. 1.5 microM) decreased IGF-I, GHR and GHBP mRNAs while it stimulated MT mRNA. However, the response of IGF-I to GH was not affected by the exposure to DTPA nor zinc excess. Furthermore, zinc repletion of primary cultured hepatocytes isolated from zinc-deprived rats did not increase IGF-I nor GHR/GHBP mRNAs. Therefore, our results suggest that the IGF-I decline induced in vivo by zinc deficiency is not caused by reduced extracellular zinc availability at the hepatocyte level. Although IGF-I and MT gene expression is down-regulated by dietary zinc depletion, underlying mechanisms of regulation are different for both genes.

Animals↗
PubMed1998

Introduction of a normal retinoblastoma (Rb) gene into Rb-deficient lymphoblastoid cells delays tumorigenicity in immunodefective mice.

Inactivation of the Rb susceptibility gene occurs in various human cancers and has been associated with tumorigenicity. Rb gene is inactivated in 30% of acute leukaemias. The effect of Rb protein expression was assessed in the lymphoblastoid cell line IM-9 defective for Rb protein, after stable transfection with a wild-type Rb gene. The Rb transgene was under the control of the MoMuLv-LTR. Protein expression by the transduced cells was confirmed by Western blot and flow cytometry analyses. Compared to the parental cell line, growth rate remained unchanged in the Rb transfected clones. In SCID mice however, tumor formation originating from these clones was delayed. The current data suggest therefore that, in this Rb-defective haematopoietic cell line, Rb expression correlates with reduced tumorigenicity but not with reduced growth rate.

Animals↗
PubMed1998

Cefepime versus imipenem-cilastatin as empirical monotherapy in 400 febrile patients with short duration neutropenia. CEMIC (Study Group of Infectious Diseases in Cancer).

This open, comparative, randomized, multicentre equivalence study compared cefepime 2 g bd and imipenem-cilastatin 1 g tds (50 mg/kg/day) as empirical monotherapy for febrile episodes in a homogeneous cohort of cancer patients with short duration neutropenia following chemotherapy for solid tumour, lymphoma or myeloma. The study was conducted in 17 French anti-cancer centres in 1995 and 1996. Response to monotherapy was assessed 7 days after treatment and was based on resolution of fever and signs and symptoms, eradication of pathogens, absence of new infection, relapse, and death of infectious origin, without addition of other antibiotics. Patients were treated for a minimum of 4 days. Of the 400 episodes randomized, 344 (86%) were evaluable for efficacy. Patient characteristics were comparable between treatment groups. Success of monotherapy was observed in 79% of episodes with cefepime and 72% with imipenem-cilastatin (equivalence, P <0.0001). The response rate for microbiologically documented infections was 66% with cefepime and 61% with imipenem-cilastatin (bacteraemic episodes: 63% for cefepime; 44% for imipenem-cilastatin). A second antibiotic (usually a glycopeptide) was added in 20% and 21% of the cases, respectively. Overall, the response to therapy, with or without an additional antibiotic, was 95% (cefepime) and 90% (imipenem-cilastatin). Survival was similar in both groups (95% and 98%, respectively). Cefepime treatment was better tolerated, with 9% of the patients experiencing related intercurrent events compared with 19% in the imipenem-cilastatin group (P = 0.003). Nausea/vomiting was significantly more frequent in the imipenem-cilastatin group (15%) than in the cefepime group (5%; P = 0.001). Cefepime monotherapy was as effective as, and better tolerated than, imipenem-cilastatin in the empirical treatment of fever during short duration neutropenia.

Antineoplastic Agents↗
PubMed1997

Neonatal arterial switch operation: coronary artery patterns and coronary events.

OBJECTIVE: To determine the incidence of coronary events following neonatal arterial switch and to identify potential risk factors for death and coronary events. METHODS: The total experience (236 consecutive arterial switch operations) of one surgeon was studied. Associated procedures included ventricular septal defect closure in 37 patients (16%) and aortic arch repair in 14 patients (6%)). The influence of various patient, procedural, support technique and experience variables was analyzed. RESULTS: There were 19 deaths (8-70% confidence limits = 6-10%). Survival at 1 month, 1 year and 5 years was 93, 92 and 92%, respectively. Risk factors for death included small birth weight (P = 0.0015), hypoplasia of right ventricle (P < 0.0001), aortic arch obstruction (P < 0.0001) and coronary patterns with coronary arteries coursing between the great arteries (P = 0.0066). Coronary events occurred in 26 patients (11-70% confidence limits = 9-13%) and involved coronary deaths (11 patients), non fatal myocardial infarctions (8 patients) and coronary stenoses or occlusions (7 patients). Freedom from coronary events at 1 month, 1 year and 5 years was 94, 91 and 88%, respectively. Risk factors for coronary events included coronary patterns with retropulmonary course of the left main or left circumflex coronary artery (P = 0.0122), coronary patterns with coronary arteries coursing between the great arteries (P < 0.0001), all variations of intramural coronary arteries (P = 0.0010) and commissural origin of coronary ostia (P = 0.0171). CONCLUSIONS: (1) In most neonates, arterial switch operation carries a low operative risk and provides excellent mid-term results; (2) The operative risk remains increased in some subsets; and (3) Some coronary patterns increase the risk of coronary events. Further surgical experience may improve the results.

Coronary Disease↗
PubMed1997

[Axillary lymphadenectomy prepared by fat aspiration versus functional axillary lymphadenectomy: preliminary results of a randomized prospective study].

The objective of this study is to compare morbidity between 2 surgical procedures of axillary clearance: functional lymphadenectomy by classical dissection versus axillary dissection prepared by liposuction (Suzanne's procedure). Two hundred consecutive patients treated for breast cancer were included in a prospective randomized trial between 1st January, 1995 and 31st January, 1996 (Huriet's law). The assessment (number of nodes, postoperative stay, drainage duration, rate of seromas, number of complications, evaluation of mobility and sensitive disorders) was done on the first, fifth, tenth and thirty postoperative days. There is no significant difference between the 2 groups. The rate of seromas decreased significantly only for fat patients (8/25 versus 21/34, p < 0.05) and for the patients treated with radical mastectomy (17/37 versus 28/39, p < 0.05). In this preliminary study, liposuction does not change postoperative effects of axillary clearance, except for fat patients or after total mastectomy. The liposuction seems to facilitate a better anatomical dissection and a better preservation of the nervous and vascular elements.

Adult↗
PubMed1997

[Dialectic behavioral psychotherapy for patients with borderline personality disorder].

Any therapist working with borderline patients knows that this is a crisis prone population that can be as burdening for the professional clinician as for the individual who experiences these intense relational episodes. Within this context, it is quite surprising that leaders of the behavioral approach waited until the beginning of the nineties before applying their technology to the treatment of patients diagnosed with borderline personality disorder. Linehan put numerous efforts to empirically demonstrate the efficiency of her newly developed dialectical behavior therapy, which makes it a noteworthy model. This article presents some historical and philosophical underpinnings of her approach, followed by the diagnostic criteria, the main clinical tools she advocates, the various dialectal dilemma, the treatment modes as well as an overview of the basic therapeutic strategies used in this approach.

Behavior Therapy↗
PubMed1996

Reconstitution of ionic channels from inner and outer membranes of mammalian cardiac nuclei.

Recent reports suggest that the nuclear envelope possesses specific ion transport mechanisms that regulate the electrolyte concentrations within the nucleoplasm and perinuclear space. In this work, intact nuclei were isolated from sheep cardiac cells. After chromatin digestion, the nuclear envelopes were sonicated and four nuclear vesicle populations were separated by sucrose step gradients (SF1-SF4). These fractions were compared by sodium dodecyl sulfate-polyacrylamide gel electrophoresis, and their protein content was analyzed by Western blot, using lamin and SEC 61 antibodies. The lamins, which are associated with the inner nuclear membrane, were present in three fractions, SF2, SF3, and SF4, with a lower amount in SF2. The SEC 61 protein, a marker of the rough endoplasmic reticulum, was detected in small amounts in SF1 and SF2. Upon fusion of vesicles into bilayers, the activities of nuclear ionic channels were recorded in 50 mM trans/250 mM cis KCl or CsCl, pH 7.2. Two types of Cl- selective channels were recorded: a large conducting 150-180-pS channel displaying substates, and a low conducting channel of 30 pS. They were both spontaneously active into bilayers, and their open probability was poorly voltage dependent at negative voltages. Retinoic acid (10(-8) M) increases the po of the large Cl- conducting channel, whereas ATP modifies the kinetics of the low conductance anion selective channel. Our data also suggest that this anionic channel is mainly present in the SF3 and SF4 population. The presence of a 181 +/- 10 pS cation-selective channel was consistently observed in the SF2 population. The behavior of this channel was voltage dependent in the voltage range -80 to +60 mV. Furthermore, we report for the first time the activity of a channel exclusively present in the SF3 and SF4 fractions, shown to contain mainly inner membrane vesicles. This cation selective channel displays a 75-pS conductance in 50 mM trans/250 mM cis K-gluconate. It is concluded that the bilayer reconstitution technique is an attractive approach to studying the electrophysiological properties of the inner and outer membranes of the nuclear envelope.

Animals↗