Search PubMed⌕ Search

Biomedical subjects

M Irfan

Publications and source records attributed to M Irfan.

34 records · Page 2Linked to original sources
PubMed1987

The hepatotoxic potential of a Prudhoe Bay crude oil: effect on mouse liver weight and composition.

The hepatotoxic properties of a Prudhoe Bay Crude Oil (PBCO) were evaluated in mice. Administration of PBCO (5.0 ml/kg body wt, daily for 2 days) to mice resulted in an increase in (i) liver wet and dry weight, (ii) hepatic total proteins, RNA, glycogen and total lipids, and (iii) individual lipids such as cholesterol, triglycerides and phospholipids. Hepatic protein biosynthesis, determined in vivo by administration of L-[14C]leucine was increased in PBCO exposed mice. The rate of 3H incorporation from 3H2O was significantly enhanced in liver fatty acids, cholesterol, triglycerides and thus ultimately in total lipids. Also, an increase in 3H incorporation was noticed in hepatic glycogen after PBCO administration. The results suggest that PBCO may induce hepatotoxicity by altering the intermediary metabolism of biochemical constituents.

Animals↗
PubMed1987

Beta dosimetry for radioimmunotherapy of cancer using labeled antibodies.

Starting with the tabulation of scaled monoenergetic electron dose point kernels F in water, according to the calculations of Berger, we have developed analytic approximations that facilitate the task for convolving F with beta spectra of specific nuclides to derive their dose point kernels J. J is well fitted by a single log-normal distribution, involving three independent parameters. For large atomic numbers, the addition of an exponential function near the origin is required. The radiation dose distribution D in a homogeneous medium of soft tissue with an activity distribution C is given by the convolution of J with C. Computer programs using fast Fourier transform techniques have been developed to evaluate the convolution efficiently. To study the perturbation of tissue inhomogeneity for D, we have used a point source of 32P and measured the increase in backscattered dose from a polystyrene/aluminum interface simulating soft tissue/bone. We have also measured the decrease in dose at a polystyrene/air interface.

Antibodies↗
PubMedDate not supplied

Effect of tissue inhomogeneity on beta dose distribution of 32P.

In a homogeneous medium of soft tissue the radiation dose distribution due to a nonuniformly distributed beta source can be calculated by convolution of the beta dose point kernel of the nuclide with the source distribution. A possible extension of the technique to the calculation of the dose distribution in heterogeneous media involving relatively simple geometric interfaces requires the knowledge of the resulting perturbation to the beta point kernels in individual media. We simulated a soft-tissue-bone planar interface by a polystyrene (PST)-aluminum junction and measured the change in beta dose from the dose value in homogeneous PST due to a point source of 32P using 7LiF thermoluminescent dosimeters. With the point source at the interface, the dose rates at 0-31, 125-156, and 283-314 mg/cm2 separations from the interface were increased by (12 +/- 3)%, (8 +/- 2)%, and (3 +/- 2)%, respectively, compared with homogeneous PST. With the point source at a PST-air planar interface to simulate a soft-tissue-air junction, the dose rates at 0-31, 139-170, and 283-314 mg/cm2 from the interface were decreased by (25 +/- 4)%, (11 +/- 7)%, and (5 +/- 2)%, respectively. The changes in dose rates for these two interfaces have also been measured with degraded spectra of 32P. Comparison of the experimental data with Monte Carlo calculation for a point source and the two-group method of calculation for a plane source is also presented.

Biophysical Phenomena↗