Establishment of autochthonous and standard cell line derived xenograft models of glioblastoma multiform in Iran

GBM is the most common and malignant astrocity tumor and it is persistent to common treatment so, these patients have a very low survival. Several researchers around the world, including Iran, have been investigated GBM-cell line in vitro. However in vivo studies have not been fulfilled. As standard cell line [U-87MG] derived from human GBM and total GBM tumor derived from 3 patients were heterotypic ally injected into 4-6 weeks old athymic nude mice. Pathologic investigation by H and E, GFAP and Ki-67 were examined 2 months post implantation. GBM characteristics appeared in H and E and GFAP and the rate of proliferation was 6% and in direct xenograft tumor was 9% which was consistent with the pathologic result of patient. GBM Xengraft is the most suitable model for in vivo investigation and researcher can evaluate new treatments for this tumor. On the other hands, Pharmacogenomics differences in treatment response could be indicated among Iranians

Acquiring molecular interference functions of X-ray coherent scattering for breast tissues by combination of simulation and experimental methods

Recently, it has been indicated that X-ray coherent scatter from biological tissues can be used to access signature of tissue. Some scientists are interested in studying this effect to get early detection of breast cancer. Since experimental methods for optimization are time consuming and expensive, some scientists suggest using simulation. Monte Carlo [MC] codes are the best option for radiation simulation; however, one permanent defect with MC codes has been the lack of a sufficient physical model for coherent [Rayleigh] scattering, including molecular interference effects. It was decided to obtain molecular interference functions of coherent X-ray scattering for normal breast tissues by combination of modeling and experimental methods. A Monte Carlo simulation program was written to simulate the angular distribution of scattered photons for the normal breast tissue samples. Moreover, experimental diffraction patterns of these tissues were measured by means of energy dispersive X-ray diffraction [EDXRD] method. The simulation and experimental data were used to obtain a tabulation of molecular interference functions for breast tissues. With this study a tabulation of molecular interference functions for normal breast tissues was prepared to facilitate the simulation diffraction patterns of the tissues without any experimental. The method may lead to design new systems for early detection of breast cancer

effect of aging on resting- state brain function: an fMRI study

Healthy aging may be accompanied by some types of cognitive impairment; moreover, normal aging may cause natural atrophy in the healthy human brain. The hypothesis of the healthy aging brain is the structural changes together with the functional impairment happening. The brain struggles to over-compensate for those functional age-related impairments to continue as a healthy brain in its functions. Our goal in this study was to evaluate the effects of aging on the resting-state activation network of the brain using the multi-session probabilistic independent component analysis algorithm [PICA]. We compared the resting-state brain activities between two groups of healthy aged and young subjects, so we examined 30 right-handed subjects and finally 12 healthy aging and 11 controls were enrolled in the study. Our results showed that during the resting-state, older brains benefit from larger areas of activation. While in young competent brains, higher activation occurs in terms of greater intensity. These results were obtained in prefrontal areas as regions with regard to memory function as well as the posterior cingulated cortex [PCC] as parts of the default mode network. Meanwhile, we reached the same results after normalization of activation size with total brain volume. The difference in activation patterns between the two groups shows the brain's endeavor to compensate the functional impairement

Functional imaging of Broca's area in native Persian speakers: an fMRI study

The problem of localization of speech associated cortices using noninvasive methods has been of utmost importance in many neuroimaging studies, but the results are difficult to resolve for specific neurosurgical applications. In this study, we used fMRI to delineate language-related brain activation patterns with emphasis on the Broca's area during the execution of two Persian language tasks. The subjects comprised of nine healthy right-handed men who participated voluntarily in this study. They performed two consequent fMRI paradigms namely; "Word Production" and "Reverse Word Reading". The fMRI data were collected and analyzed. Then, functional images were registered to anatomical images using FSL software. The laterality indices were also calculated in regions of interest with different threshold levels. The results indicate that Broca's area, as the classical language-production center, was robustly activated while performing these two tasks. In eight out of nine subjects, the left hemisphere dominancy and Broca's area activation were observed and in one case activation was prominent in the homologous area in the right hemisphere. Similar pattern of cortical activation during Persian word production and Anglophone languages such as English was revealed. fMRI is a valuable means for brain mapping in language studies

FMRI study of human visual cortex in response to spatiotemporal properties of visual stimuli

The brain response to temporal frequencies [TF] has been already reported, but with no study reported for different TF with respect to various spatial frequencies [SF]. fMRI was performed by 1.5T GE-system in 14 volunteers during checkerboard, with TFs of 4, 6, 8 and 10Hz in low and high SFs of 0.5 and 8cpd. Average percentage BOLD signal change demonstrated the amplitude of the fMRI response to different TFs was maximal in 6Hz for high SF of 8cpd, while, it was maximal at TF of 8Hz for low SF of 0.5cpd. The results are useful for vision therapy [such as the treatment of Amblyopia] and visual task selecting in fMRI studies

Spatial frequency dependence of the human visual cortex response on temporal frequency modulation studied by fMRI

The brain response to temporal frequencies [TF] has been already reported. However, there is no study on different TF with respect to various spatial frequencies [SF]. Functional magnetic resonance imaging [fMRI] was done by a 1.5 T General Electric system for 14 volunteers [9 males and 5 females, aged 19'26 years] during square-wave reversal checkerboard visual stimulation with different temporal frequencies of 4, 6, 8 and 10 Hz in 2 states of low SF of 0.4 and high SF of 8 cycles/degree [cpd]. All subjects had normal visual acuity of 20/20 based on Snellen's fraction in each eye with good binocular vision and normal visual field based on confrontation test. The mean luminance of the entire checkerboard was 161.4 cd/m2 and the black and white check contrast was 96%. The activation map was created using the data obtained from the block designed fMRI study. Pixels with a Z score above a threshold of 2.3, at a statistical significance level of 0.05, were considered activated. The average percentage blood oxygenation level dependent [BOLD] signal change for all activated pixels within the occipital lobe, multiplied by the total number of activated pixels within the occipital lobe, was used as an index for the magnitude of the fMRI signal at each state of TF and SF. The magnitude of the fMRI signal in response to different TF's was maximum at 6 Hz for a high SF value of 8 cpd; it was however, maximum at a TF of 8 Hz for a low SF of 0.4 cpd. The results of this study agree with those of animal invasive neurophysiologic studies showing SF and TF selectivity of neurons in visual cortex. These results can be useful for vision therapy and selecting visual tasks in fMRI studies

Application of small angle X-ray scattering [SAXS] for differentiation between normal and cancerous breast tissues

Small angle X-ray scattering [to angles less than 10[degree sign]] is predominantly coherent. Coherent scattering leads to diffraction effects and especially constructive interferences. These interferences carry some information about the molecular structure of the tissue. As breast cancer is the most widespread cancer in women, this project evaluated the application of small angle X-ray scattering [SAXS] for differentiation between normal and cancerous breast tissues. The energy dispersive method with a set up including X-ray tube, primary collimator, sample holder, secondary collimator and HP Ge detector was used. The best constructive interference was found to be at 6.5[degree sign] after doing experiments on adipose breast tissue at several angles of 4, 5, 6, 6.5 and 7.3 degrees. The total number of 99 breast tissue samples, including normal and tumor were studied at the 6.5[degree sign]. The corrected intensity versus momentum transfer was obtained for each sample. Adipose tissue shows a sharp peak in low momentum transfer region. It is easy to separate adipose tissue and mixed tissue [adipose and fibroglandular] from tumor in peak positions [each coherent scattering spectrum has a peak that its position is determined by momentum transfer]. Furthermore adipose tissue has shown significantly higher peaks than other breast tissues. Benign and malignant breast tissues were differentiated by both peak positions and peak heights [each peak has a height in coherent scattering spectrum]. Preservation of samples nitrogen tank had no effects on molecular structure of the breast tissue. By energy dispersive small angle X-ray scattering, it is possible to differentiate between normal, benign and malignant breast tissues

Application of small angle X-ray scattering [SAXS] with synchrotron facility in differentiation between normal and tumoral breast tissues

Breast cancer is the most widespread cancer in women. Early detection of this disease has been identified as a major effective factor to save the lives of many women. The ability of small angle X-ray scattering to provide molecular in formations on live tissue has led to investigate the possibility of exploiting coherent scattered X-rays as a diagnostic tool in breast cancer. In this study an angular dispersive set up was used in Daresbury laboratory [UK]. 84 human breast tissue biopsies including 50 cancerous and 34 normal tissues were studied. For this study a beam size of 0.5 mm2 at the sample and a wavelength of 1.54 ? were used. The other included conditions were, the sample to detector distance [SSD], 2000 m and exposure time of 200 sec. Data were recorded using the Daresbury 2-D multiwire proportional counter operated at 512 512 pixels. The region between the specimen and detector was evacuated to minimize air scatter. With exposure to the each sample, at first a two dimensional image was produced and then the corrected intensity versus momentum transfer [Q] was plotted by using PCDetpack software. It was found that there was a noticeable coherent intensity difference between tumor and normal breast tissues especially in the range of Q from 0.4-0.7 nm-1, that the coherent X-ray scattering intensity in the tumor breast tissue was significantly higher [P < 0.0001, CI= 95%] than in the normal breast tissue in the 0.4-0.7 nm -1 range. In this study, by using 2 m distance of camera collagen diffraction peaks were seen at 0.3 and 0.45 nm-1. Applying SAXS, it is possible to differentiate normal and tumoral breast tissues as separated groups [P < 0.0001, CI = 95%], on the base of integrated intensity, in the 0.4-0.7 nm -1 range. Since having collagen damge in tumors, is probable therefore, it is suggested to do some cytocellular examinations on tumoral tissues

Determination of Superficial Dose Profile in Z-Line for Each Slice in CT. Scan Machines

CT.Scan examinations cause high patient absorbed dose from x-ray ionizing radiation. Therefore it is necessary to obtain superficial dose profile in Z-line. In this research 11 thermoluminecent dosimeter [TLD], after calibration were located on Z line perpendicular to slice thickness. CT.Scan machines did X-ray exposures. The resultant dose profiles showed gussian shape apperience, which has severed dose reduction off the slice thickness. By attention to high patient absorbed dose in CT.Scan machines, it is better to referre that patients towards any other diagnostic methods with lower risk and reasonable quality