فهرست مطالب

Iranian Biomedical Journal - Volume:7 Issue: 2, Apr 2003

Iranian Biomedical Journal
Volume:7 Issue: 2, Apr 2003

  • 54 صفحه،
  • تاریخ انتشار: 1382/02/24
  • تعداد عناوین: 8
  • Mahnaz Tashakori, Soheila Ajdary, Amina Kariminia, Fereidoun Mahboudi, Mohammad Hossein Alimohammadian Page 43

    Both zoonotic and anthroponotic cutaneous leishmaniasis (CL) caused by L. major and L. tropica, respectively, are endemic in different parts of Iran. This study was performed to investigate the new changes in epidemiological pattern of CL, and to identify the species of Leishmania and the strains of L. major isolated from different endemic areas of Iran. Seventy-two isolates from 245 samples collected from different endemic areas of Iran were characterized by monoclonal antibodies (mAb) specific for L. major, L. tropica, and L. infantum. Flow cytometry, isoenzyme analysis and PCR amplification were used for identification. Isoenzyme analysis was carried out by PAGE and cellulose acetate. Eight enzymes including malate dehydrogenase (MDH), malic enzyme (ME), glucose 6-phosphate dehydrogenase (G6PD), glucose phosphate isomerase (GPI), nucleoside hydrolase inosine (NHi), nucleoside hydrolase deoxy inosine (NHd), superoxide dismutase (SOD) and 6-phosphogluconate dehydrogenase (6PGD) were used for isoenzyme analysis. PCR assay was developed using specific primers against kinetoplast DNA. The isolates were compared with reference strains (RS). Data obtained from different methods showed 45 out of 72 isolates were similar to RS of L. major and 22 similar to L. tropica, and also five samples were identified as Crithidia. Isoenzyme migration pattern of L. major isolates was indistinguishable from each other in six enzymatic systems but differences were observed in profile of two enzymes of SOD and MDH. The data indicate that L. major species are dominant in the studied endemic areas, and different strains of L. major are present in different geographic areas of Iran. Moreover, it seems that enzymatic system is more useful approach than others for characterization of Leishmania species and L. major strains.

  • Ftemeh Karami, Tehrani, Siamak Salami Page 51
    Apoptosis could be a major mechanism of antitumor effect of tamoxifen. Therefore this study is designed to characterize the kinetic behavior of tamoxifen-induced apoptosis in the estrogen receptor positive (ER+) and negative (ER-) cell lines, MCF-7 and MDA-MB-468. Frequency of cell death was examined by trypan blue and acridine orange staining. Annexin V-Fluorescein/PI was used in flow cytometry for distinguishing the dividing, apoptotic and necrotic cells and Hoechst 33258 staining was also applied to detect apoptotic changes in the nuclear morphology. The results showed that tamoxifen was able to induce apoptosis in both cell lines (χ2 test, P<0.05). In contrast to the MCF-7 cells, which responded to the low concentrations of tamoxifen (0.5-1μM), the treated MDA-MB-468 cells were affected at 20 μM (χ2 test, P<0.05). However, the kinetic data revealed that tamoxifen, at higher doses stimulates the ER+ cell proliferation. This is the first study showing these opposite effects in the kinetics of tamoxifen treated cells. Therefore it may serve as a guideline for the precautionary evaluation of suggested high doses of tamoxifen.
  • Mahmoud Salami Fumitaka, Tadaharu Tsumoto Page 57
    There are some conflicts about constancy of conduction velocity (CV) in a given tract of nervous system. By recording excitatory postsynaptic currents (EPSC) in layer IV of the somatosensory cortex we tried to clear changes in CV of thalamocortical tract of mice aged 3 to 50 days old. Field potentials and EPSC were recorded in the layer IV by stimulation of ventrobasal nucleus of thalamus (VB) and white matter (WM). Our results indicate that in mice aged 3 through 17 days old, CV of EPSC evoked by WM and VB stimulation increased up to 2 and 15 times, respectively. Also, the data from field potentials match those from EPSC. CV enhancement of the fibers out of cortex may contribute to myelination as well as increased diameter of neurites. However, it is not the case for WM matter stimulation-evoked responses.
  • Mohammad Hassan Pipezadeh, Abdulrahman Dezfuline, Mohammad Hadi Koocheck, Mehrdad Moradi Page 65

    The aim of the present study was to clarify if old N-MRI rat, a strain which is easily available in Iran and cheap to maintain, is a suitable alternative to those previously reported. In this model, we compared three quantifiable parameters between old and young rats: biochemically, involving measurement of differences in the lipid profile. Histologically, the differences of the thickness of the wall of the aorta, the apparent degree of splitting within the aortic media, and the formation of foamy lipid layers on the outermost layer of the aorta. Pharmacologically, in vitro contractile responses/mg wet tissue weight to submaximal concentration of phenylephrine (1 µM) and the rate of relaxation min–1 mg–1 tissue weight following administration of 0.1 mM of acetycholine. The proposed model was validated using lovastatin as test drug known for its lipid lowering and anti-atherosclerosis actions. The results showed that this model to be reliable, quantifiable and capable of detecting the effect of orally administered lovastatin. We recommend this model as an easy and accessible experimental model for various atheroscleorosis investigations.

    Keywords: Atherosclerosis, Model, N-MRI rat, Lipids, Foam cells
  • Ali Asghar Moshtaghie, Mohammad Ali Ghaffari Page 73
    Indium is a heavy metal belonging to group IIIa. It is believed that indium may interfere with iron metabolism from the sites of absorption, transportation, utilization and storage in the cells. The present investigation was established to study and compare the binding of iron and indium to human apo-transferrin (apo-tf). Pure human apo-tf was used and the binding activity of iron and indium, as a complex with citric acid (1:20), to apo-tf was studied. The binding of iron and indium to apo-tf in Tris-HCl buffer, pH 7.4 showed a maximum absorbance at 465 and 255 nm, respectively. The binding of both metals to apo-tf appears to be pH dependent. Using equilibrium dialysis technique, the binding of iron to apo-tf and the effect of indium on the binding process were also studied. Addition of indium to the outside of dialysis sac reduced iron uptake by 37%. The results indicate that indium competes with iron in binding to apo-tf. Although, the binding sites for these two ions seem to be similar, the binding of iron to apo-tf is more tightly than indium.
  • Mohammad Reza Safari Page 79
    Antioxidant consumption has been reported to be inversely associated with the incidence of coronary artery disease. To clarify the possible role of vitamin E and volatile oils in the prevention of atherosclerosis, the effects of these compounds on the susceptibility of low-density lipoprotein (LDL) to oxidative modification were investigated. In this study, vitamin E and seven volatile oils “anethol, eugenol, geraniol, limonene, linalool, pulegone and thymol” were added to plasma and incubated at 37°C for 3 h. The LDL fraction was separated by ultracentrifugation and the oxidizability of LDL was estimated by measuring conjugated diene (CD), lipid peroxides and thiobarbituric acid-reactive substances (TBARS) after cupric sulfate solution was added. The data show that vitamin E, thymol and eugenol significantly and dose-dependently prolonged the lag time before initiation of oxidation reaction (P<0.01 by ANOVA). Also, vitamin E and thymol suppressed the formation of lipid peroxides and TBARS more markedly than other volatile oils. The ability to prolong lag time, suppression of lipid peroxides and TBARS formation was in the following order: vitamin E > thymol > eugenol > geraniol > linalool > limonene > anethol > pulegone. These data clearly show that LDL exposed to vitamin E and volatile oils in vitro reduces oxidizability; therefore have favorable effects in ameliorating atherosclerosis.
  • Homayoun Homayounfar, Arezou Nahavandi Page 85
    Decreased cardiac responsiveness to adrenergic stimulation has been observed in cholestatic liver disease, but the cause remains unclear. Previous reports have suggested that nitric oxide overproduction might have a role in cholestasis-induced bradycardia via inhibition of L-type calcium channels. In the present study, the digoxin has been used to increase cardiac Ca2+ transient in male Sprague-Dawley rats with obstructive cholestasis and the chronotropic responsiveness to adrenergic stimulation was evaluated. Cholestasis was induced by surgical ligation of the bile duct under general anesthesia and sham-operated animals were considered as control. The animals were divided into two groups, which received either digoxin (10, 20 mg/kg/day) or saline. One week after the operation, spontaneously beating atria were isolated and chronotropic responses to epinephrine were evaluated in a standard oxygenated organ bath. The basal spontaneous beating rate of the atria in the cholestatic animals was not significantly different from that of sham-operated rats in vitro. Meanwhile, cholestasis induced a significant decrease in chronotropic effect of epinephrine. This effect was corrected by daily administration of digoxin (20 mg/kg/day). The results also showed that plasma alkaline phosphatase activity was increased by bile-duct ligation, and digoxin treatment had no effect in the elevation of this marker of liver damage. The protective effect of digoxin on impaired chronotropic responsiveness to adrenergic stimulation in cholestatic rats might be related to increase of Ca2+ transient. However, further studies are necessary to confirm the molecular basis of this effect.
  • Maryam Kamkar, Mostafa Saadat, Iraj Saadat, Golbahar Haghighi Page 89

    Phenylketonuria (PKU) is one of the most common metabolic inborn diseases caused by mutations in the phenylalanine hydroxylase (PAH) gene. This gene is linked to a variable number of tandem repeats (VNTR) region which is a polymorphic marker that facilitates the implementation of prenatal diagnosis and carrier screening. In this study, VNTR with 13 repeats that has not been reported previously was observed in 2 PKU families from Fars province, south of Iran. This allele showed 4% frequency in normal individuals.