ABSTRACT: The lifestyle risk factors for nasopharyngeal carcinoma (NPC) in North Africa are not known.
From 2002 to 2005, we interviewed 636 patients and 615 controls from Algeria, Morocco and Tunisia, frequency-matched by centre, age, sex, and childhood household type (urban/rural). Conditional logistic regression was used to evaluate the association of lifestyles with NPC risk, controlling for socioeconomic status and dietary risk factors.
Cigarette smoking and snuff (tobacco powder with additives) intake were significantly associated with differentiated NPC but not with undifferentiated carcinoma (UCNT), which is the major histological type of NPC in these populations. As demonstrated by a stratified permutation test and by conditional logistic regression, marijuana smoking significantly elevated NPC risk independently of cigarette smoking, suggesting dissimilar carcinogenic mechanisms between cannabis and tobacco. Domestic cooking fumes intake by using kanoun (compact charcoal oven) during childhood increased NPC risk, whereas exposure during adulthood had less effect. Neither alcohol nor shisha (water pipe) was associated with risk.
Tobacco, cannabis and domestic cooking fumes intake are risk factors for NPC in western North Africa.
British Journal of Cancer 10/2009; 101(7):1207-12. · 5.04 Impact Factor
British Journal of Cancer 08/2009; 101(7):1207-1212. · 5.04 Impact Factor
ABSTRACT: Nasopharyngeal carcinoma (NPC) is one of the most common malignant tumors in Southern China, especially in the Guangdong area. To demonstrate a comprehensive profile of loss of heterozygosity (LOH) in NPC, we applied a large panel of 382 microsatellite polymorphism markers covering all the 22 autosomes in 98 cases of sporadic primary NPC. Of the 335 informative markers, 83 loci showed high level of LOH (presence in equal to or more than 30% cases) and most of the high frequent loci were clustered to chromosome 1p36 and 1p34, 3p14-p21, 3p24-p26, 3q25-q26 and 3q27, 4q31 and 4q35, 5q15-21 and 5q32-q33, 8p22-p23, 9p21-p23 and 9q33-q34, 11p12-p14, 13q14-q13 and 13q31-q32, 14q13-q11, 14q24-q23 and 14q32. High frequency of LOH was found in chromosomes 3, 5, 9 and 11 (>/=50%), while medium frequency of LOH was found in chromosomes 1, 4, 6, 14, 17 and 19 (40-49%). Several new regions showing high frequency of LOH were found in chromosome 1p36, 3q25-q26, 3q27, 5q15-q21, 8p22-p23 and 11p12-14. The relationship between LOH and TNM stage of NPC was evaluated. Regions 6p23 (D6S289), 8p23.1 (D8S549) and 9q34.2 (D9S1826) showed higher frequency of LOH in later stages (III and IV) than in earlier stages (I and II) (P<0.05). Thus, our study provides a global view on allelic loss in the development of NPC and should shed light on the way for localization of putative tumor suppressor genes associated with the pathogenesis of NPC.
International Journal of Oncology 12/2000; 17(6):1267-75. · 2.40 Impact Factor
ABSTRACT: The SP (signal processing) Education Laboratory (an educational project at the University of Michigan) is a software package designed to provide a highly interactive, flexible environment within which students can explore basic concepts of signal processing. The authors summarize the basic features of this software, some of the reasoning behind certain design decisions, and experience in using this software as a teaching tool.< >
Acoustics, Speech, and Signal Processing, 1993. ICASSP-93., 1993 IEEE International Conference on; 05/1993 · 4.63 Impact Factor
ABSTRACT: Results are presented concerning the problem of identifying
temporal structure in composite sources. An alternative class of
techniques for identifying the underlying structure of a SCS (structured
composite source) from its estimated transition matrix is proposed.
These techniques are postulated directly with respect to the discrete
elements of a Markov chain and allow for non-hierarchical and
hierarchical decomposition. The general structure of this class is
developed, and examples based on a specific clustering algorithm are
Circuits and Systems, 1990., Proceedings of the 33rd Midwest Symposium on; 09/1990
ABSTRACT: An extension of the hidden Markov framework which may lead to
substantial reductions in the complexity of implementing such a
framework for speech modeling and recognition is proposed. This
extension is suggested by the observation that speech statistics exhibit
temporal structure over multiple time scales. Such temporal variation
leads naturally to a special structure for the HMM (hidden Markov
model). The structured composite source (SCS) is introduced as a
generalization of the HMM. Theorems are developed for representing an
arbitrary HMM as an SCS using techniques developed for multiple time
scale analysis of weakly coupled Markov chains. Modification of the
algorithms for the estimation of HMM parameters from sample data, the
forward-backward and the baum-Welch algorithms, is straightforward, and
results in a significant reduction in the computational complexity of
the reestimation procedure
Circuits and Systems, 1989., Proceedings of the 32nd Midwest Symposium on; 09/1989