[3D planning : from carcinological resection to maxillofacial reconstruction]. / La médecine du futur. Planification 3D : de la résection carcinologique à la reconstruction maxillo-faciale.

The use of new technologies in medicine becomes more and more frequent because they allow us to raise therapeutic quality. This is the case in maxillofacial surgery. 3D planning for oncological resection and reconstruction brings many benefits. In this article, we will present the first case operated with this technology at CHU Liege and discuss the advantages and disadvantages of this technique.

L'utilisation des nouvelles technologies en médecine devient de plus en plus fréquente car elles permettent d'augmenter la qualité thérapeutique. C'est le cas dans le domaine de la chirurgie maxillo-faciale. La planification 3D des chirurgies de résection oncologique et de reconstruction apporte de nombreux bénéfices. Dans cet article, nous vous présentons le premier cas opéré grâce à cette technologie au sein du CHU Liège et discutons des avantages et inconvénients de cette technique.

[Alcohol consumption and head and neck cancer]. / Consommation d'alcool et cancers ORL.

Alcohol is often considered as a simple co-factor, potentiating the carcinogenic effect of tobacco, in head and neck cancer. However, its own effect is less clear. It has been recognized by the International Agency for Research on Cancer (IARC) as a risk factor for head and neck cancer for many years. It seems that the risk is a function of the importance of consumption, with certain genetic predispositions. This risk can also decrease if consumption stops, with a prolonged interruption. In addition, alcohol consumption may have a negative influence on the prognosis of patients with this type of cancer. A preventive action is therefore essential, among other things via information to the patient provided by health providers.

En cancérologie ORL, l'alcool est souvent considéré comme un simple co-facteur, potentialisant l'effet carcinogène du tabac. Son effet propre est moins clair. Il est pourtant reconnu par le Centre International de Recherche sur le Cancer (CIRC) comme un facteur de risque de cancer ORL depuis de nombreuses années. Il semble que le risque soit fonction de l'importance de la consommation, avec la contribution de certaines prédispositions génétiques. Ce risque peut également diminuer en cas d'arrêt de la consommation, moyennant un arrêt prolongé. Par ailleurs, la consommation d'alcool pourrait avoir une influence néfaste sur le pronostic des patients atteints de ces cancers. Une action préventive est donc primordiale, entre autres interventions, via l'information du patient par le corps médical.

Zoledronic acid treatment impairs protein geranyl-geranylation for biological effects in prostatic cells.

BACKGROUND: Nitrogen-containing bisphosphonates (N-BPs) have been designed to inhibit osteoclast-mediated bone resorption. However, it is now accepted that part of their anti-tumor activities is related to interference with the mevalonate pathway. METHODS: We investigated the effects of zoledronic acid (ZOL), on cell proliferation and protein isoprenylation in two tumoral (LnCAP, PC-3,), and one normal established (PNT1-A) prostatic cell line. To assess if inhibition of geranyl-geranylation by ZOL impairs the biological activity of RhoA GTPase, we studied the LPA-induced formation of stress fibers. The inhibitory effect of ZOL on geranyl geranyl transferase I was checked biochemically. Activity of ZOL on cholesterol biosynthesis was determined by measuring the incorporation of 14C mevalonate in cholesterol. RESULTS: ZOL induced dose-dependent inhibition of proliferation of all the three cell lines although it appeared more efficient on the untransformed PNT1A. Whatever the cell line, 20 microM ZOL-induced inhibition was reversed by geranyl-geraniol (GGOH) but neither by farnesol nor mevalonate. After 48 hours treatment of cells with 20 microM ZOL, geranyl-geranylation of Rap1A was abolished whereas farnesylation of HDJ-2 was unaffected. Inhibition of Rap1A geranyl-geranylation by ZOL was rescued by GGOH and not by FOH. Indeed, as observed with treatment by a geranyl-geranyl transferase inhibitor, treatment of PNT1-A cells with 20 microM ZOL prevented the LPA-induced formation of stress fibers. We checked that in vitro ZOL did not inhibit geranyl-geranyl-transferase I. ZOL strongly inhibited cholesterol biosynthesis up to 24 hours but at 48 hours 90% of this biosynthesis was rescued. CONCLUSION: Although zoledronic acid is currently the most efficient bisphosphonate in metastatic prostate cancer management, its mechanism of action in prostatic cells remains unclear. We suggest in this work that although in first intention ZOL inhibits FPPsynthase its main biological actitivity is directed against protein Geranylgeranylation.

Effect of Wound Position, Auxin, and Agrobacterium vitis Strain F2/5 on Wound Healing and Crown Gall in Grapevine.

ABSTRACT Agrobacterium vitis is the causal agent of crown gall disease in grapevine, which can be severe in many regions worldwide. Vitis vinifera cultivars are highly susceptible to freeze injury, providing the wounds necessary for infection by A. vitis. Wound position in relation to the uppermost bud of cuttings was determined to be important in tumor development. Inoculated wounds below buds developed tumors, whereas wounds opposite the bud did not, implying that indole-3-aectic acid flow contributes to tumor formation. If auxin was applied to wounds prior to inoculation with a tumorigenic A. vitis strain, all sites of inoculation developed tumors, accompanied by an increased amount of callus in the cambium. Wounds inoculated with an A. vitis biological control strain F2/5 prior to application of the pathogen did not develop galls. A closer examination of these wounds determined that callus cells formed in the cambium during wound healing are susceptible to transformation by the pathogen. Although the mechanism by which F2/5 prevents transformation is unknown, our observations suggest that F2/5 inhibits normal wound healing by inducing necrosis in the cambium.

Factors affecting pharmacokinetic variability of oral topotecan: a population analysis.

The aim of this study was to characterise the pharmacokinetics of the anticancer agent topotecan, and explore the influence of patient covariates and interoccasion variability on drug disposition. Data were obtained from 190 patients who received the drug as a 30-min infusion (N=72) or orally (N=118). The population model was built with the use of NONMEM to identify candidate covariates, and obtain models for clearance (CL) and volume of distribution. The final models were based on first-order absorption with lag-time (oral data), and a two-compartment model with linear elimination from the central compartment. The Cockcroft-Gault creatinine clearance (CrCl) and WHO performance status (PS) were the only significant covariates: CL=(12.8+2.1 x CrCl) x (1-0.12 x PS). For the volume of distribution, a correlation was found between body weight and the central volume (V1)=0.58 x body weight. Based on the structural models, a limited-sampling strategy was developed with minor bias and good precision that can be applied a posteriori using timed samples obtained at 1.5, and 6 h after the administration of topotecan. In conclusion, a population pharmacokinetic model for topotecan has been developed that incorporates measures of renal function and PS to predict CL. In combination with drug monitoring, the limited sampling strategy allows individualised treatment for patients receiving oral topotecan.

Polyethylene glycol embedment for histological studies of bean seed testa of low moisture content.

Light microscopic examination of the structure of seed testa of snap and semihard bean seeds with 6% and 12% moisture contents in paraffin sections was unsuccessful because of poor paraffin infiltration and subsequent separation of subjacent and palisade cell layers. We devised an alternative method using polyethylene glycol (PEG) as the embedding material. Specimens were killed and fixed in the usual manner. They were then run up through a graded series (25, 50, 75, 100%) of PEG 1000 to PEG 1450, and finally embedded in a mixture of PEG 1450 and 4000 (19:1 by weight). Transverse and longitudinal sections retained excellent morphological detail and were suitable for histological study. Sections temporarily stained with 0.025% thionin allowed good quality photomicrographs.