Ventilator associated pneumonia and endotracheal tube repositioning: an underrated risk factor.

Aspiration of secretions toward lower airways potentially occurs during endotracheal tube (ETT) repositioning in mechanically ventilated patients in the intensive care unit and may be a risk factor for developing ventilator-associated pneumonia (VAP). This case-control study confirms that repositioning of the ETT is an independent risk factor for VAP.

[Ameloblastoma of the jaws. A retrospective analysis from 1994 to 2007]. / Améloblastomes des mâchoires. Analyse rétrospective de 1994 à 2007.

INTRODUCTION: Ameloblastomas and keratocysts are the most frequent epithelial odontogenic tumors of the jaws. They have a high recurrence rate. This retrospective study reviews the features of ameloblastomas operated on in our unit from 1994 to 2007. PATIENTS AND METHODS: The studied parameters were sex, ethnic origin, age at diagnosis, clinical signs, radiographic presentation, site distribution, histological type, treatment, and follow-up records. RESULTS: One hundred and sixteen patients were included (with 239 surgical samples). The mean age was 36 years, with a majority of Europeans, 60% of multilocular radiolucent lesions with root resorption, mandibular location (93%). Twenty-one percent of the patients presented with an impacted tooth, the third molar in 79% of cases. Fifty percent of the lesions were from 5 to 13cm in length, 10% longer than 13cm. The most common histological type was follicular ameloblastoma. Patients were treated by enucleation in 82% of cases and radical mandibular resection with reconstruction in 11% of cases. The follow-up was documented for 96% of the patients with a 44% recurrence rate. Seventy-four percent of patients with a double recurrence presented with a "follicular" ameloblastoma. DISCUSSION: We prefer a well-performed enucleation which preserves surrounding bone. The high rate of follicular type recurrence should more systematically lead to a combined treatment: periostectomy and tooth extraction. Our data was compared with previously published large series.

Decision-making needs of patients with depression: a descriptive study.

The study's purpose was to explore the decision-making needs of patients considering treatment options for their depression. Semi-structured interviews were guided by the Ottawa Decision Support Framework. Of 94 participants, 67 were uncertain about their decision. Common decisions identified were whether or not to take medications, attend support groups, undergo electroconvulsive therapy, and location of care. Those feeling certain were more likely to have made a decision (RR 1.37; 95% CI: 1.05, 1.78). However, 40 patients who had 'made a decision' in the recent past were uncertain about their decision. Compared with those who were certain, the uncertain group felt less informed (2.65 vs. 1.64; P < 0.001), less supported (2.63 vs. 1.88; P < 0.001) and less clear about how they valued the benefits and risks of options (2.57 vs. 1.69; P < 0.001). Other influential factors included concerns about confidentiality, distress from depression, embarrassment, panic attacks and lack of energy. Few patients wanted to defer decision making to their physician (n = 8) or family (n = 1). To support decision making, participants identified the need for: discussions with their psychiatrist, nurse or family doctor; access to printed information; and information provided by health professionals and health societies.

[Giant-cell tumors: three recurrent cases in young patients]. / Tumeurs à cellules géantes: à propos de trois cas récidivants chez des sujets jeunes.

INTRODUCTION: True giant-cell tumor is a rare jaw osteolytic benign tumor belonging to the larger family of giant-cell tumors. It is particular because of the risk of recurrence and potential metastatic spread. OBSERVATION: Since 1973, we have managed four cases of true giant-cell tumors in our unit. The three cases reported here concerned young patients who developed recurrence after tumorectomy-curettage. DISCUSSION: Based on a literature review we defined this entity among the other giant-cell tumors. We emphasize the importance of early definitive diagnosis based on rigorous clinical and radiological confrontations. Because of its benign nature, the most conservative surgical treatment (tumorectomy-curettage) is generally proposed for the young patient. We noted however that in the three cases presented here, more radical surgical treatment with an enlarged tumorectomy removing the adjacent bone was advisable because of the high risk of recurrence and metastasis.

[Double-barrel fibular free flap for mandibular reconstruction: beneficial alternative for dental implanted rehabilitation (5 cases)]. / Lambeau libre de péroné en double barre: intérêt du montage dans les reconstructions mandibulaires pour une réhabilitation prothétique sur implants (5 cas).

INTRODUCTION: As major loss of mandibular bone stock requires a vascularized transfer, fibula free flap reconstruction is considered to be the best free flap for its length and reliability. Its main advantage is to accept dental implants. Single or double-barrel reconstruction can be performed. Double-barrel reconstruction is generally preferred because the bone superposition offers enough height to allow dental implants. MATERIAL AND METHODS: We reviewed five selected cases of double-barrel fibula free flap adaptive mandibular reconstruction performed among a series of 11 oral rehabilitations with planned dental implants, focusing on the technical aspects. RESULTS: Today, dental rehabilitation has been achieved in three double-barrel fibula flaps. Details are reported concerning the implant step. DISCUSSION: In this perspective, we discuss the choice of the reconstructive technique in order to obtain adequate bone height. Early in our experience and for different reasons discussed in the text, we used a single barrel fibula flap. This technique provided sufficient height in some cases, but had to be completed by bone grafts in few patients. Our experience illustrates the usefulness of the double barrel technique which provide definitive bone height sufficient for dental implants. The double-barreled technique should be considered as the best solution.

Influence of atmospheric pollution on the lead content of wines.

Over the last century, the atmospheric fallout of anthropogenic lead has evolved with time, as a function of the chronological variability of transient lead inputs from both industrial and gasoline origins. This variability has been mostly documented over North America and northern Europe. In this study we used ICP-MS for the determination of lead isotope ratios and showed that a series of French wines followed the evolution of the environmental lead record over the last century. We observe the same three-step chronological evolution of the lead isotopic composition, which reflects a western European signal. In the post 1950 vintages, the lead isotope composition reflects a dominant atmospheric fallout. Since approximately 1950, Pb concentrations have been much lower than before, decreasing consistently from approximately 0.25 mg l-1 around the early 1950s, down to less than approximately 0.1 mg l-1 nowadays. Reflecting the airborne pollution, the lead isotopic signature is also specific of the continental origin of the wines and lead isotope ratios determination in wines appears to be a promising tool for certifying wine authenticity.

New 4-point pharmacophore method for molecular similarity and diversity applications: overview of the method and applications, including a novel approach to the design of combinatorial libraries containing privileged substructures.

A new 4-point pharmacophore method for molecular similarity and diversity that rapidly calculates all potential pharmacophores/pharmacophoric shapes for a molecule or a protein site is described. The method, an extension to the ChemDiverse/Chem-X software (Oxford Molecular, Oxford, England), has also been customized to enable a new internally referenced measure of pharmacophore diversity. The "privileged" substructure concept for the design of high-affinity ligands is presented, and an example of this new method is described for the design of combinatorial libraries for 7-transmembrane G-protein-coupled receptor targets, where "privileged" substructures are used as special features to internally reference the pharmacophoric shapes. Up to 7 features and 15 distance ranges are considered, giving up to 350 million potential 4-point 3D pharmacophores/molecule. The resultant pharmacophore "key" ("fingerprint") serves as a powerful measure for diversity or similarity, calculable for both a ligand and a protein site, and provides a consistent frame of reference for comparing molecules, sets of molecules, and protein sites. Explicit "on-the-fly" conformational sampling is performed for a molecule to enable the calculation of all geometries accessible for all combinations of four features (i.e., 4-point pharmacophores) at any desired sampling resolution. For a protein site, complementary site points to groups displayed in the site are generated and all combinations of four site points are considered. In this paper we report (i) the details of our customized implementation of the method and its modification to systematically measure 4-point pharmacophores relative to a "special" substructure of interest present in the molecules under study; (ii) comparisons of 3- and 4-point pharmacophore methods, highlighting the much increased resolution of the 4-point method; (iii) applications of the 4-point potential pharmacophore descriptors as a new measure of molecular similarity and diversity and for the design of focused/biased combinatorial libraries.

Functional characterization of the S. cerevisiae genome by gene deletion and parallel analysis.

The functions of many open reading frames (ORFs) identified in genome-sequencing projects are unknown. New, whole-genome approaches are required to systematically determine their function. A total of 6925 Saccharomyces cerevisiae strains were constructed, by a high-throughput strategy, each with a precise deletion of one of 2026 ORFs (more than one-third of the ORFs in the genome). Of the deleted ORFs, 17 percent were essential for viability in rich medium. The phenotypes of more than 500 deletion strains were assayed in parallel. Of the deletion strains, 40 percent showed quantitative growth defects in either rich or minimal medium.

[Leiomyosarcoma of the gingiva. Apropos of a case. Review of the literature]. / Léiomyosarcome de la gencive. A propos d'un cas. Revue de la littérature.

Leiomyosarcoma (LMS) accounts for 7% of all smooth tissue sarcomas. The rarity of smooth muscle cells in the oral cavity makes LMS a rare tumor in this localization. We report a case of gingival LMS in a 43-year-old woman. We reviewed 23 cases of LMS or the oral cavity report in the literature since 1980. Age of occurrence varied from 2.5 to 63 years with a predominance in the 20 to 30 years age range. In two-thirds of the cases, the first symptom was the development of a painful mass. In half the mass developed in the maxilla and in one-quarter it occurred in the gingival mucosa alone. In nearly all cases treatment was wide excision resection. Surgery with chemotherapy and radiotherapy is reserved for high-grade or recurrent leiomyosarcoma.

Mesenchymal chondrosarcoma of the jaws. Report of four cases.

Mesenchymal chondrosarcoma (MCS), described in 1959 by Lichtenstein & Bernstein, is a very rare malignant tumour. Only 46 cases have been previously reported in the jaws. Over a period of 30 years, four chondrosarcomas of mesenchymal type (of which one has already been published in 1987 with a three-month follow up) were treated in our department. Two patients have been followed for more than 17 years, of whom one has died of an intracranial extension and the other is still alive after surgical treatment of numerous recurrences and metastases. The two others are tumour-free with a follow up of 18 months and 11 years respectively. Histological, epidemiological and clinical features and treatment of MCS are discussed relevant to the data published in the literature.

Infrahyoid myocutaneous flap in reconstructive maxillofacial cancer and trauma surgery.

We report the use of an island infrahyoid myocutaneous flap, pedicled on the superior thyroid vessels, in a group of 21 patients. This flap allows reconstruction of intraoral defects or defects of the lower portion of the face, as large as 10 x 4 cm. We used it in 15 cases to repair parts of the oral cavity, after tumour resection, in 2 patients with mandibular osteoradionecrosis and in 4 patients with gunshot injuries. Among the 21 flaps, no muscular necrosis was observed; however, 4 total necrosis and 4 partial necrosis (< or = 25% of the skin area) of the skin paddle were recorded. Loss of the skin paddle was primarily attributable to the anatomical variations of the veins draining this flap.

Synthesis and diversity analysis of lead discovery piperazine-2-carboxamide libraries.

A Lead Discovery Library of piperazine-2-carboxamide derivatives was produced for general screening. This paper discloses two novel solid phase synthetic routes used to produce 15,000 single compounds via the Irori directed sorting technique. Computational methods such as reagent clustering and library profiling were used to maximize reagent diversity and optimize pharmacokinetic parameters. The results of a four center pharmacophore analysis revealed the added diversity gained by using two independent synthetic routes.

Selective effect of thiazides on the human osteoblast-like cell line MG-63.

Thiazide diuretics have been shown to decrease bone-loss rate and to improve bone mineral density in patients using this medication. However, the exact role of thiazides on bone cells is still debated. In the present work, we studied whether thiazides could affect the normal features of osteoblasts using the human model cell line MG-63. Hydrochlorothiazide (HCTZ) did not affect cell growth nor DNA synthesis in these cells, yet slightly increased alkaline phosphatase activity in these cells at pharmacologically relevant concentrations. Under similar conditions, HCTZ dose-dependently inhibited 1,25(OH)2D3-induced osteocalcin secretion by these cells (maximal effect, -40 to 50%, P < 0.005). However, HCTZ did not inhibit the basal production of osteocalcin in MG-63 cells (without 1,25(OH)2D3 induction), which was very low to undectable. Two different thiazide derivatives, chlorothiazide and cyclothiazide, and two structurally related sulfonamides with selective inhibition of carbonic anhydrase (Acetazolamide) or hyperglycemic effects (Diazoxide) were also tested. Chlorothiazide (1000 microM) inhibited osteocalcin secretion (-42 +/- 12.7%) at doses 10-fold higher than HCTZ (100 microM) while cyclothiazide was effective at doses of 1 microM (-27 +/- 3.6%), and hence 100-fold lower than HCTZ, compatible with the relative natriuretic effect in vivo of these compounds. Acetazolamide (10 microM) poorly affected osteocalcin secretion at doses 100-fold higher than those needed in vivo to inhibit carbonic anhydrase. Likewise, Diazoxide (100 microM) poorly affected osteocalcin secretion at doses known to promote its biological effect. Higher doses of acetazolamide and diazoxide induced cell death. Neither Acetazolamide nor Diazoxide affected alkaline phosphatase, whereas chlorothiazide had a weak positive effect on this enzymatic activity. The production of macrophage colony-stimulating factor (M-CSF) was stimulated in the presence of 1,25(OH)2D3 (50 nM), TNF-alpha (2 ng/ml) or both in MG-63 cells. HCTZ (25 microM, 24 hr of preincubation) did not modify basal M-CSF production and did not reduce the response to 1,25(OH)2D3 alone. In contrast, HCTZ inhibited the response to TNF-alpha alone (P < 0.05), and also reduced the response to a combination of 1,25(OH)2D3 and TNF-alpha (P < 0.01). In conclusion, these results indicate that thiazide diuretics show a selective inhibition of osteocalcin secretion and M-CSF production by MG-63 cells unlike structurally related drugs. Therefore, these features may explain, in part, the positive effect of thiazides on bone mineral density.

Demonstration of an osteoblast defect in two cases of human malignant osteopetrosis. Correction of the phenotype after bone marrow transplant.

Osteopetrosis is an inherited disorder characterized by bone sclerosis due to reduced bone resorption. Here we report that human osteopetrotic osteoblast-like (Ob) cells express a defective phenotype in primary cultures in vitro, and that bone marrow transplant (BMT) corrects osteoblast function. DNA analysis at polymorphic short-tandem repeat loci from donor, recipient, and primary Ob-like cells pre-BMT and 2 yr post-BMT revealed that Ob were still of recipient origin post-BMT. Osteopetrotic Ob-like cells obtained pre-BMT showed normal and abnormal 1,25(OH)2D3-induced alkaline phosphatase (ALPase) and osteocalcin production, respectively, and failed to produce macrophage colony-stimulating factor (M-CSF) in response to IL-1a and TNF-alpha. These parameters were all normalized in primary Ob-like cells prepared 2 yr post-BMT. X-linked clonality analysis at the human androgen receptor (HUMARA) locus revealed that osteoblasts showed a polyclonal and an oligoclonal derivation pre- and post-BMT respectively, indicating that a limited number of progenitor reconstituted this population. Because osteoblasts were still of recipient origin post-BMT, this suggests that functional osteoclasts, due to the replacement of hematopoeitic cells, provided a local microenvironment in vivo triggering the differentiation and/or recruitment of a limited number of functional osteoblasts.

[A brown tumor of the mandible and hyperparathyroidism secondary to chronic renal insufficiency. Review of the literature apropos of a case]. / Tumeur brune de la mandibule et hyperparathyroïdie secondaire à une insuffisance rénale chronique. Revue de la littérature à propos d'un cas.

We report on a brown tumor of the mandible in a hemodialysed female patient with severe uncontrolled secondary hyperparathyroidism. Multiple other brown tumors were associated. The hyperparathyroidism was treated with a subtotal parathyroidectomy because only three parathyroids were found. Parathyroid removal led to normal C-terminal parathyroid hormone concentration (0 ng/ml). A review of the literature has shown that parathyroidectomy is usually curative. Our patient demonstrated, eleven days after the parathyroid surgery, rapid growth of the mandibular tumor. This unusual evolution has justified a local excision of the tumor. Histological preparations have confirmed the diagnostic of brown tumor with an important capillary proliferation.

[An auricular prosthesis attached by intra-mastoid implants. Apropos of 11 cases]. / Prothèse auriculaire fixée sur implants intramastoïdiens. A propos de 11 observations.

The use of osseointegrated implants to provide support for auricle prosthesis as been carried out by Tjellstrom. This method has provided the maxillofacial surgeon with another approach to the treatment of defect of the auricle. The principles and concepts of extra-oral osseointegrated implants are the same as those of the intra-oral application developed by Branemark 26 years ago. This simple and reliable method allow the attachment to splint bar fixated to three or two mastoid osseointegrated implants. This method represent an interesting possibility for the management of auricle defects. We report on our experience of 11 cases.

A survey of different high resolution visualization modes of a volumetric object with applications.

In view of the variety of 3D representation techniques, a clinical study was carried out in order to evaluate their respective usefulness. It appears that a single technique cannot be claimed to be valid for all clinical situations and that a combination of representations brings more relevant information. Among the different techniques a clear delineation must be established between those which allow the accurate definition of landmarks (multiplanar reformation, surface representation), and those which do not (integral shading, reconstructed radiology). The main point is the possibility to recognize anatomical landmarks on these latter modes and to choose oblique cut planes in relation to them. Visualization quality is strongly dependent upon the acquisition protocol which must provide a spatial resolution as isotropic as possible.

[Cervical Castleman's disease in a 12 year-old child]. / Maladie de Castleman cervicale chez un enfant de 12 ans.

A case of unifocal cervical Castleman's disease without systemic manifestations occurring in a 12 year-old child is reported. Histological examination showed the characteristic features of angiofollicular lymph node hyperplasia. The results of immunological and in situ hybridization studies are also reported. A local IL6 secretion in the interfollicular areas was demonstrated.