Reduced body weight in male Tspan8-deficient mice.

OBJECTIVE: The gene TSPAN8 was recently identified in a genome-wide association study as the most likely causal gene in a locus that was correlated with the risk of type 2 diabetes (T2D) in northern European individuals. To assess whether Tspan8 is the actual T2D-causal gene in this locus, we ablated its expression in mice and determined the consequences of this ablation on a multitude of metabolic traits. RESULTS: We found that genetic ablation of Tspan8 in mice results in a reduction (-15.6%) in the body weight of males fed a normal chow diet and that this deficiency results in a resistance to body weight gain (-13.7%) upon feeding a high fat and high carbohydrate diet. The differences in body weight could only be detected in male mice and were the consequence of both a decrease in fat deposition, and a decrease in lean body mass (16.9 and 11%, respectively). In spite of the significant body weight difference, no changes in fasting insulin and glucose levels could be detected in Tspan8 knockout mice, nor could we identify changes in the clearance of glucose or sensitivity to insulin in oral glucose tolerance test and intraperitoneal insulin sensitivity test studies, respectively. In addition, male Tspan8 knockout mice showed significantly lower bone mineral density and phosphorus levels (6.2 and 16.6%, respectively). Expression of Tspan8 in mouse was highest in digestive tissues, but virtually absent from the pancreas. In contrast, expression of human TSPAN8 was substantial in digestive tissues, as well as pancreatic cells. CONCLUSIONS: Our results argue for a role for Tspan8 in body-weight regulation in males, but do not show differences in T2D-associated traits that were anticipated from previous human genome-wide association studies. Differences in Tspan8 expression levels in mouse and human tissues suggest that Tspan8 could fulfill different or additional physiological functions in these organisms.

A unique PPARgamma ligand with potent insulin-sensitizing yet weak adipogenic activity.

FMOC-L-Leucine (F-L-Leu) is a chemically distinct PPARgamma ligand. Two molecules of F-L-Leu bind to the ligand binding domain of a single PPARgamma molecule, making its mode of receptor interaction distinct from that of other nuclear receptor ligands. F-L-Leu induces a particular allosteric configuration of PPARgamma, resulting in differential cofactor recruitment and translating in distinct pharmacological properties. F-L-Leu activates PPARgamma with a lower potency, but a similar maximal efficacy, than rosiglitazone. The particular PPARgamma configuration induced by F-L-Leu leads to a modified pattern of target gene activation. F-L-Leu improves insulin sensitivity in normal, diet-induced glucose-intolerant, and in diabetic db/db mice, yet it has a lower adipogenic activity. These biological effects suggest that F-L-Leu is a selective PPARgamma modulator that activates some (insulin sensitization), but not all (adipogenesis), PPARgamma-signaling pathways.

[The trapezoid face: transversal excess in the maxillary area]. / Le visage trapézoïdal: excès transversal au niveau de l'étage inférieur de la face.

The patient who consults for "big cheeks" usually desires correction for an excess of tissue in the masseter region. First all neoplastic pathologies recognized by their unilateral asymmetry are excluded in order to focus on bilateral phenomena. Three anatomical elements can be responsible either alone or in association for this excess: the parotid gland, the masseter muscle and the angle of the jaw. The clinical and complementary examinations leading to the etiological diagnosis are described. The treatment recommended is specific to the structure involved and is not necessarily surgical.

[Maxillary metastasis of malignant thymoma]. / Métastase maxillaire d'un thymome malin.

The authors report a case of maxillary metastasis in the follow up of a malignant thymoma. It seems to be the first case reported in today's scientific literature. The clinical presentation, histopathological features and prognosis of malignant thymoma are discussed. The worse influence of distant metastasis on survival rate is state precisely.

[Value of interrupted resection of the lateral crus in surgery of the nasal tip]. / Intérêt de la résection interruptrice de la crus latérale dans la chirurgie de la pointe du nez.

Three goals have to be achieved in the surgery of the tip of the nose. Separately or joined together, they contribute to modify the height, rotation or width of the tip. Interrupting resection of the upper legs gives the ability to modify both the projection and the rotation of the tip. The authors present this technique, emphasizing the precise location of the knee of the upper legs and the interest to perform interrupting resections laterally to this region.

[Osteosynthesis using resorbable plates in maxillofacial surgery: hopes and disappointments]. / L'ostéosynthèse par plaques résorbables en chirurgie maxillo-faciale: espoirs et désillusions.

The use of absorbable osteosynthesis material has two advantages in maxillofacial surgery: suppressing the possible biological effects of implanted metallic foreign bodies, making second surgery for material removal useless. Although the biotolerance of currently used materials is well known, the authors intended to test their use in the specific conditions of maxillofacial surgery, in which simply extrapolating the data collected in general surgery leads to erroneous conclusion. The authors report the results of a preliminary clinical study on 21 cases of osteosynthesis of the upper third of the face using absorbable plates (18 fractures of the zygomatic bone, 3 maxillary osteotomies). The biotolerance of the material is very good, after more than 3 years for the oldest cases. The mechanical stability of the assembly is sufficient for the selected indications. As regards disappointments, these include the thickness of the plates, the difficulty to adapt them to bony surfaces, the fragility of the screws and the slow resorption of the material.

[Carcinoma cuniculatum. Apropos of 4 cases with orofacial involvement]. / Epithélioma cuniculatum. A propos de 4 cas de localisation oro-faciale.

Carcinoma cuniculatum, a rare variant of verrucous carcinoma, was first described in the foot. The authors report 4 cases of uncommon localizations of this tumor, involving oral cavity and face, 3 of them having a 6-year follow-up. The specific histological and clinical features of this tumor are remembered and the difficulties of its diagnosis are emphasized. This slow-growing, ulcerated proliferation, invading the surrounding tissues, is often responsible for chronic suppuration, but very rarely metastasizes to the regional lymph nodes. The surgical treatment consists in a wide excision; neck dissection is theoretically useless, and radiotherapy is strictly contraindicated because of the risk of transformation into an anaplasic carcinoma. For all these reasons, carcinoma cuniculatum must be considered as an anatomoclinic entity, and deserves to be known by the clinicians and the pathologists.

Is the myosin type altered in the aging platysma?

The myosin light chains of platysma samples originating from 2 to 86 year old patients of the maxillo-facial surgery clinic were investigated. The platysma contained both fast and slow myosin. No change in the proportion of myosin type in relation to age was found. Female patients often displayed less fast myosin than male patients. Each time when the platysma muscle activity has been reduced a decrease in the amount of slow myosin light chains was observed. In the reported study, variations of the fast and slow myosin light chains resulted mainly from the platysma activity level, i.e. from the pathology requiring the surgery, rather than from the patients' age.

[Surgical treatment of hypoplasia of the ascending ramus of the mandible in children using an autologous osteochondral costal graft]. / Traitement chirurgical de l'hypoplasie de la branche montante de la mandibule chez l'enfant par greffon costal autologue ostéochondral.

To lengthen the child's mandibular ramus, we use, since 1977, an autologous osteochondral rib graft fixed to the posterior margin of the ramus. Experimental studies show that this graft has a growth potential, the osteochondral junction responds to the biomechanical forces in a similar way to the mandibular condyle. Surgical treatment allows an immediate restitution of the morphology, normal masticatory function and good buccal opening. The interposition of cartilage prevents recurrence. The growth potential of the graft due to osteochondral junction activity, allows surgery to be performed in childhood, without requiring a further surgical operation several years later. This constitutes an optimistic prospect for the future and the good results obtained with 8 patients are analyzed.

[A trial of stimulation with tamoxifen of progesterone nuclear receptors in patients with kidney cancer]. / Essai de stimulation par le tamoxifen des récepteurs nucléaires à la progestérone chez les patients porteurs de cancer du rein.

Stimulation of progesterone receptors synthesis by Tamoxifen was tried in 19 patients with renal cell carcinoma. No difference was found between this series and 51 controls.

Monocortical miniplate osteosynthesis.

The theoretic basis of noncompression plating using miniplates and monocortical screws is explained. The technique is described and the range of clinical applications in maxillofacial trauma and elective maxillofacial osteotomies is indicated.