Showing papers by "National Defence University, Pakistan published in 2004"

Treatment of bladder carcinomas using recombinant BCG DNA vaccines and electroporative gene immunotherapy

Abstract: Intravesical immunotherapy with live Mycobacterium bovis bacillus Calmette–Guerin (BCG) is the treatment of choice for superficial bladder cancers. Nevertheless, a significant proportion of patients do not respond to this therapy, and adverse effects are common. Here, we report the cloning of recombinant mycobacterial DNA vaccines and demonstrate the ability of multicomponent and multisubunit DNA vaccines to enhance Th1-polarized cytokine-mediated responses as well as effector cell responses. Splenocytes from immunized groups of mice were restimulated in vitro and examined for cytotoxicity against murine bladder tumur (MBT-2) cells. We used four combined recombinant BCG DNA vaccines (poly-rBCG) for electroporative gene immunotherapy (EPGIT) in vivo, and found that tumor growth was significantly inhibited and mouse survival was prolonged. Increased immune cell infiltration and induction of apoptosis were noted after treatment with poly-rBCG alone, with the murine interleukin-12 (mIL-12) vaccine alone, and—most significantly—with the poly-rBCG+mIL-12 vaccine combination. Electroporation of poly-rBCG+mIL-12 resulted in complete tumor eradication in seven of eight mice (P<.01) within 28 days. Thus, EPGIT using multicomponent multisubunit BCG is highly effective in the treatment of bladder cancer. This approach presents new possibilities for the treatment of bladder cancer using recombinant BCG DNA vaccines.

Theoretical study of the inter-ionic and inter-molecular hydrogen bonds constructed by GZT, ZT2− ions and their relative derivatives

Abstract: Diguanidinium 5,5′-azotetrazolate (GZT) is an ionic type high energy compound, which is combined with two guanidinium C(NH2)3+ (or simplified as G+) cations and one ZT2− dianion. The structure of the ZT2− is constructed using two N4C tetrazole type five membered rings which are connected by an azo type (–N N–) linkage. A similar type of ‘inter-ionic hydrogen bonding type high energy compounds’ which were formed with various cations and ZT2− have also been reported in the recent experimental paper. Within the limitations of quantum mechanical calculations, the combination of ZT2− anions and cations with –NH2 or with –OH groups have been selected for the theoretical study of this near planar sandwich type structure. With B3LYP/6-311+G(2d,p) and B3LYP/6-31G(d,p) density function theory (DFT) type SCF calculations, we found a set of varying types of inter-ionic or inter-molecular hydrogen bonding systems. When using the –NH2 group in the cation, the inter-ionic system is the easily formed in most of the cases. But when substituting the –NH2 with the –OH group in the cation, the hydrogen bonding system will be transformed into the inter-molecular type molecular combination of H2ZT and formic acid molecules, or into the mixed inter-ionic and inter-molecular hydrogen bonding system of HZT− anion, formalmide molecule and some cations after the optimization procedures of the DFT type calculation. The stepwise type energy differential method found with bsse (basis-set superposition error) corrections and the various localized type analyses of H-bonding problems are processed together to determine H-bonding strengths. The order of localized H-bond strengths for each of the structures found with the differential method is arranged for all of the studied systems. The consistent results of the various methods are successfully obtained for the determination and comparison of localized H-bond strengths.

Relaxation spectrum calculation methods and their use to determine the molecular mass distribution of propylene, ethylene and α-olefin random copolymers

Abstract: In the present study a nonlinear regression with regularization and inverse Fourier transformation methods were developed to determine the relaxation spectrum from the frequency-dependent storage and loss modulus data. The spectra obtained were used for the determination of the molecular mass distribution in a calculation process developed by D.W. Mead [(1994) Journal of Rheology 38 1797]. The molecular mass distributions of propylene–α-olefin and ethylene–α-olefin random copolymers have been determined by rheological and gel permeation chromatography methods and the distributions obtained by the two methods agreed quite well with each other.

Singular optimal control system designed by generalized singular linear exponential quadratic Gaussian performance index

Abstract: In this paper we originally develop a generalized linear exponential quadratic Gaussian technique to design singular optimal control systems. The proposed method is successfully applied for an autopilot design of high performance bank-to-turn missile. Finally compared with the generalized singular linear quadratic Gaussian method, the numerical simulations present the results and demonstrate the benefits of the proposed method.

Generating functions for the numbers of pyramid and staircase polyhedra

Abstract: We have derived the five-variable generating functions for the numbers of pyramid and staircase polyhedra on the cubic lattice with given values of width, depth, height, area and volume.