Gene Expression-Based Glioma Classification Using Hierarchical Bayesian Vector Machines

This paper considers several Bayesian classification methods for the analysis of the glioma cancer with microarray data based on reproducing kernel Hilbert space under the multiclass setup. We consider the multinomial logit likelihood as well as the likelihood related to the multiclass Support Vector Machine (SVM) model. It is shown that our proposed Bayesian classification models with multiple shrinkage parameters can produce more accurate classification scheme for the glioma cancer compared to several existing classical methods. We have also proposed a Bayesian variable selection scheme for selecting the differentially expressed genes integrated with our model. This integrated approach improves classifier design by yielding simultaneous gene selection

Arylazoimidazole complexes of lead(II)-halide and their photochromism

418-426Lead(II) complexes of 1-alkyl-2-(arylazo)imidazole (Raai-CnH2n+1), [Pb(Raai-CnH2n+1)X2] (X = Cl, Br, I; and Raai-CnH2n+1, R = H, Me and n = 4, 6, 8) have been characterized by UV-vis, IR and 1H-NMR spectroscopy. The coordinated Raai-CnH2n+1 in the complexes undergoes E-to-Z (trans-to-cis) isomerisation about the –N=N– group upon being irradiated with UV light in DMF solution. The rate and quantum yields of E-to-Z photoisomerisation (φE→Z) of the complexes are poorer than the respective free ligand response and are also affected by the nature of halide present (Cl-, Br- and I-). Variation in physicochemical parameters may be correlated with the effective mass of the photochrome. The rate of isomerisation follows the sequence: [Pb(Raai-CnH2n+1)Cl2] nH2n+1)Br2] nH2n+1)I2]. The Z-to-E isomerisation has been carried out at varying temperatures (298–308 K) to determine the activation energy of Z-to-E (cis-to-trans) isomerisation (Ea: 47.09–63.42 kJ mol-1) and the entropy of activation (S : 166.52 to –109.0 J mol-1 K-1) which is a large negative in the complexes. Theoretical calculation supports cleavage of Pb(II)-N(azo) bond followed by the –N=N– rotation in a three-coordinated symmetry rather than the four-coordinated symmetry

Prescribed dose versus calculated dose of spinal cord in standard head and neck irradiation assessed by 3-D plan

Background and Purpose: Spinal cord toxicity can be dreaded complication while treating head and neck cancer by conventional radiotherapy. Cord sparing approach is applied by two phase planning in conventional head neck radiotherapy. In spite of cord sparing approach spinal cord still receives considerable scatter dose. Our study aims to do the volumetric analysis of spinal cord dosimetry and to correlate with the clinical findings. Materials and Methods: Treatment planning was done in two phases. First phase treatment fi elds include gross disease- both tumor and involved nodes. in the second phase, treatment field shrinkage was done to cover the gross disease sparing the spinal cord. These fields are termed as off-cord fields. 42 patients with histological proven squamous cell carcinoma of the head and neck region were analysed with two groups. In Group A, 46 Gy was given in 23 fractions, and then tumor-boost with off-cord fi eld received 24 Gy in 12 fractions. In Group B 50 Gy was prescribed in 25 fractions initially, then off-cord fi eld given 20 Gy in 10 fractions to analyze theoutcome. Planning Computed tomography (CT) scan was done Philips Brilliance 16 slice CT scan machine, and contouring and dose calculation were done at ASHA treatment planning software. Results: Maximum dose and dose at 1 cm3, 2 cm3, and 5 cm3 were calculated. Maximum dose to cord was 52.6 Gy (range 48.1-49.7 Gy) in Group A and 54.3 Gy (range 51.48-52.33 Gy) in Group B initially. Off-cord fi elds received mean dose 8.07 Gy (85.85% of maximum) in Group A and 5.47 Gy (86.84% of maximum) in Group B. At the end of 6 months from the last date of radiotherapy, grade 1 spinal cord toxicity found in two patients in Group A and one patient in Group B respectively (P = 0.55). Both groups received additional dose, which are higher than the prescribed dose, but no patients show significant spinal cord toxicity after 6 month of follow-up. Conclusion: Spinal cord received scatter dose which much higher than the predicted dose in conventional radiotherapy of head neck cancer. Short term follow up failed to establish clinical correlation with volumetric dose of spinal cord. Two phase cord sparing head neck radiation planning if practiced should be used with caution