Effect of the heavy metals on the developmental stages of ovule and seed proteins in Chenopodium botrys L. (Chenopodiaceae).

Excessive amounts of heavy metals adversely affect plant growth and development. Also, the presence of elevated levels of heavy metal ions triggers a wide range of cellular responses including changes in gene expression and synthesis of metal-detoxifying peptides. The overall objective of this research was to elucidate some microscopic effects of heavy metals on the formation, development, and structure of ovule and seed storage proteins in Chenopodium botrys L. To achieve this purpose, the surrounding area of Hame-Kasi iron and copper mine (Hamedan, Iran) was chosen as a polluted area where the amount of some heavy metals was several times higher than the natural soils. Flowers and young pods were removed from nonpolluted and polluted plants, fixed in FAA 70 and subjected to developmental studies. Our results showed that heavy metals can cause some abnormalities during the ovule developmental process. Decreasing the size of embryo sac, quick growth of inner integument, quick degradation of embryonic sac cells, accumulation of dark particles, irregularity, and even blockage of the nuclear envelope formation and increasing of embryonic sac cytoplasm concentration were the effects of heavy metals. Reduction of ovule number was also seen in the plants collected from polluted area. For protein studies, mature seeds were harvested from nonpolluted and polluted plants at the same time. Seed storage proteins (water soluble ones) were extracted and studied by sodium dodecyl sulfate-polyacrylamide gel electrophoresis after being prepared. The results revealed that there were no significant differences between seed protein bands of polluted and nonpolluted samples, but the quantity of protein bands was different, and there was a slight quantitative increase of bands with molecular mass of 35 and 15 kD and decrease of a band with molecular mass of 17 kD in the plants collected from the mine area.

Echinococcus granulosus: lethal effect of low voltage direct electric current on hydatid cyst protoscoleces.

We have studied a small scale method for killing hydatid cyst protoscoleces using low voltage direct electric current. After collecting hydatid cysts from infected organs of slaughtered animals, protoscoleces were cultured in four different media: hydatid cyst fluid, RPMI, normal saline, and Tris buffer, respectively. Protoscoleces from each of the above media were then transferred to an electrolysis device through which different electric current densities were applied. For measuring the survival rate of protoscoleces, flame cell movement and eosin staining was used. The results show that the survival rate of protoscoleces in hydatid fluid was dependent on the electric current density and the time of the applied current. Current densities of 62.5 mA/cm2 (11 V), 53.71 mA/cm2 (10 V), and 18.18 mA/cm2 (5 V) after 1, 2, and 3 min, respectively, killed all the parasites in the hydatid fluid. However, a current density of 7 mA/cm2 (9 V) in RPMI medium after 3 min was most effective.

Pulmonary nodules: effect on detection of spiral CT pitch.

PURPOSE: To compare spiral computed tomography (CT) performed at increased pitch with spiral CT performed at standard pitch in the detection of pulmonary nodules. MATERIALS AND METHODS: Spiral CT scanning of the thorax was performed with a pitch of 1.0 in 109 patients with pulmonary nodules due to metastases. The patients were also randomly assigned to undergo further scanning with a pitch of 1.2 (n = 34), 1.5 (n = 37), 2.0 (n = 38) at the same scanning session. The scan pairs were analysed for number, size, and distribution of nodules. RESULTS: A bias toward undercounting was noted on scans with a pitch of 1.5 and 2.0; however, this was not statistically significant. Correlation coefficients were r = .982, r = .977, and r = .989 for scans of pitch 1.2, 1.5, and 2.0, respectively. Disease in one patient would have been prospectively understaged from findings on a scan of pitch 2.0 because of poor conspicuity of a small solitary nodule. CONCLUSION: Findings from scans with increased pitch generally agree well with those from scans with standard pitch; however, there is a greater risk of understaging of disease in patients with solitary nodules as pitch increases. Pitch should be limited to no greater than 1.5 for initial staging of pulmonary metastatic disease.

Comparison of spiral-acquisition computed tomography and conventional computed tomography in the assessment of pulmonary metastatic disease.

In a prospective study, spiral-acquisition computed tomography (SACT) of the thorax was evaluated in 104 patients with extrathoracic malignancy and suspected pulmonary metastases, and was directly compared with conventional computed tomography (CCT) in 23 patients. The following parameters were assessed: lesion detectability; the effect on lesion detectability of reconstruction of scans at 5 mm and 10 mm slice increments; breathing artefact and slice misregistration. The radiation dose of the two techniques was measured using thermoluminescent dosimeters placed within an anthropomorphic chest phantom, and the visibility of simulated metastases inserted into the phantom was also compared using CCT, standard SACT and SACT with pitch greater than 1.0. Where metastases were present, SACT scans showed significantly better lesion detectability than CCT scans (p < 0.001). Image reconstruction of SACT data at 5 mm increments conferred no significant advantage in lesion detectability over 10 mm increment reconstructions. Compared with CCT, SACT scans showed reduced breathing artefact, and a complete absence of slice misregistration (p < 0.01). Phantom measurements of radiation dose and resolution were similar for both techniques. Increasing the pitch of the spiral in SACT caused only a small decrease in phantom resolution, but with the advantage of a reduction in the radiation dose. Spiral-acquisition CT is superior to conventional CT for the assessment of pulmonary metastatic disease.