Iranian Journal of Basic Medical Sciences
Year:2003 | Volume:6 | Issue:2 (18)|Papers Count:9

The requirement of long time and the usage of highly volatile carcinogen solvent, i.e. propylene oxide in tissue processing have created limitations in the ultimate usage of Transmission Electron Microscopy (TEM) as a valuable tool in biological studies and diagnostic procedures. In this study, as the soft tissues the liver, skin, brain and intestine of a Albino Swiss Mice, Charles Revere Strain, were processed by applying a normal method requiring 74 hours and a rapid method which proposed to be 6 hours. In rapid method, the size of the specimens was reduced to 0.5 cubic millimeters, collidine-HCI was used to facilitate the penetration of osmium tetroxide in the tissues and the tissues were cured in 85°C. In each method, the use of acetone as a low toxic solvent was compared with propylene oxide and their influences in the quality of the cellular structures and the parametric changes of the organelles of different target cells were studied. By comparing the results, it was shown that the quality of the studied tissues were preserved and meaningful (p<0.05) changes in the sizes of the organelles of the studied cells were observed. The results revealed that by the use of acetone instead of propylene oxide, the time of processing will be reduced and the whole procedure will be more convenient. Therefore, comparing with the long method by the use of propylene oxide, rapid method by the use of acetone could be more convenient in soft tissue processing for TEM, using the procedures described in this study.      

AgNOR staining as a cell proliferating marker has been used in the diagnosis, differentiation, and prognosis of different malignant and benign neoplasms. This study was performed in order to evaluate the application of AgNOR staining technique in differentiation of malignant from benign lymphoid lesions and also in classification of different types of lymphoma. In this technique the numbers and the mean of maximum diameter of dots in cell nuclei are measured on optical microscopy level. In this study, 100 cases of benign and malignant lymphoid lesions were collected and paraffin sections of 311ftfhiickness were prepared (fixed in 10% formalin). The quality and quantity values of nucleolar organizer regions (NORs) were evaluated by means of AgNOR staining method. The numbers of AgNOR dots on 100 cells in each slide were counted randomly by optical microscopy method by oil immersion lens with x1000 magnification. Maximum diameter (Dmax) of AgNOR dots was measured by morphometric interactive image analysis system (Carl-zeiss) on photographic pictures taking by digital camera microscope on final magnification of x4000. AgNOR staining was performed by modified Crocker technique. The number of mean AgNOR count, the percent of cells witch have more than 3 dots, equal or more than 5 dots and Dmax of AgNORs were evaluated for correlation and significance of difference between values using statistical software of SPSS. It was observed that the mean counts of AgNOR dots and the percent of cells with more than 3 and equal or more than 5 dots were significantly increased in reactive nodes, Hodgkin disease and malignant lymphomas respectively. There were increasing values for the mean counts of AgNOR dots and the percent of cells with more than 3 and equal or more than 5 dots, from low grade to intermediate and finally high-grade Non Hodgkin's lymphomas. The order was reverse for Dmax of AgNORs in above cases (greater values in reactive nodes and less value in high grade Non Hodgkin's lymphomas). Also the changes in parameter of D max values were according to prognostic classification of Hodgkin disease. In all cases the differences between values were highly significant (p<0.001) and strong correlation was observed between parameters. It seems, AgNOR staining is a valuable and simple method for differentiation of neoplastic and reactive lymphoid lesions, classification of Non-Hodgkin's lymphomas and prognosis.    

Hexachlorobutadiene (HCBD), a by-product in the synthesis of perchloroethylene and trichloroethylene and a prominent environmental pollutant, is one of the most nephrotoxic chlorinated-hydrocarbons in rodents. Its organ-specific toxicity is based on a bioactivation mechanism that includes hepatic conjugation with glutathione to produce (penta-chloro, butadienyl)-glutathione (PCBG) and finally to (pentachloro butadienyl)-cysteine (PCBC), translocation and subsequent enzymatic degradation to toxic metabolites by the enzyme C-S-lyase/GTK/KAT. In this study we attempted to determine whether HCBD is a site-specific neurotoxin in the young rat. In this research, 28-day old male Wistar albino (W/A) rats were used. Groups of rats received daily doses of HCBD 25mg /kg, ip (low dose), for 2, 3, 4 and 7 days and 100mg/kgbody weight, ip (high dose), for one and two days. Control group received corn oil, 1ml /kg, ip. Animals were killed, the brain removed, halved, one half fixed in formalin and embedded in paraffin for histopathology and the other half was frozen in dried-ice isopantane for enzyme assay. Sections of 5 µm were prepared and stained with hematoxylin and eosin. Light microscopic examination showed an extensive damage in the choroids plexus of lateral and third ventricles in HCBD treated rats, especially in 1-day HCBD (100mg/kg) treated group, compare with control and other groups. In groups treated with low dose of HCBD there is a minor haemorrhage in lateral ventricles with pyknotic and mitotic figures in coroidal cells. Glutamine transaminase K (GTK) specific activity in high dose treated groups was lower than control group. In low dose treated groups GTK specific activity showed higher, but not significantly, than that of control group. In high dose treated groups the activity of GTK was lower than control. Data have shown that HCBD is a neurotoxin and choroid plexus in the lateral and third ventricles is the most sensitive organ that is affected.        

One of the important disorders subsequent to spinal cord injury is the sexual disorders at both sexes. This can be the source of psychic and mental problems for patients. The purpose of the present study is to investigate histological and morphological changes of ovary at the acute phase after spinal cord injury. Adult female Wistar rats divided two groups (Experimental =EXP and control =CON groups) each group contain 24 rats. The spinal cord of EXP animals transected by bilateral laminectomy on level T9. The animals of both groups were killed at 7th, 14th and 21st days from operation and their weight,the weight and volume of ovaries were measured. The specimens serially sectioned in 4 micrometre and the slices were stained by the H&E, PAS and Trichrome masson methods. The quantitative and qualitative of samples changes were studied by light microscope equipped with eye piece and statistically analyzed using t-test and ANOVA. The results 'show that the animal weight, the volume and weight of ovaries decreased at three EXP groups (p<0.05). In the EXP groups the diameter of follicle and ovum and the thickness of granulose layer decreased significantly in different kinds of follicles (Multilaminar primary follicle = MPF, Primary antral follicle = PAF, Secondary antral follicle = SAF and Graafian follicle = GF) (P<0.05). Also the thickness of zona pellocida decreased at PAF, SAF and GF in EXP groups (P<0.05). The thickness of theca intena of SAF and GF decreased significantly in the groups of 14th and 21th days and (P<0.05).The ovarian stroma showed Edema, Fibrosis, Hypercellularity and Vasodilation. These findings suggest that spinal cord injury induced histological changes and hetrogenic increase at ovarian structure. This probably results from the lack of an autonomic function and the modification at the neurotransmiters.      

Helicobacter pylori are the most important cause of chronic stomach infection, chronic gastritis, peptic ulcers and gastric cancer in men. This gram-negative microorganism is S-shaped, microaerophillic and has potent urease activity. After H. pylori ingestion, the microorganism attaches to the epithelial surface of stomach and is clonized. Subsequently, the physiologic and cytological damage is occurred. In the present work stomach biopsies were prepared by an experienced endoscopist physician, inoculated in transport media and sent to laboratory. Concurrently, 5ml blood sample was   obtained from patients. Biopsy sample was homogenized in an aerobic sterile condition and then was cultured on selective media for 5 to 7 days at 37°C the pure colonies were harvested from media and preserved in PBS sterile solution, then, samples subjected to ultrasound waves that caused bacteriallysis.12.5% SDS-PAGE using wide range molecular weight marker was done. Lysed bacteria were divided to pure protein fractions by Gel filtration chromatography. Samples were quantified by spectrophotometer. Samples with high absorbance were incubated with positive sera and result was analyzed in regard to positive response in dot-blotting method. Antigenic profile of lysed bacterial electrophoresis indicates protein precipitation in 21, 8 kilo Dalton area. These results indicate the ability of antigens in stimulating immune response. Also in negative samples, a lower antibody response was seen. Therefore intact bacteria are not suitable for serological diagnosis and only specific proteins should be used for this purpose.      

Glycoconjugates have an important role in prolifration, differentiation and cell interactions as well as in spermatogenesis and fertilization. Among them, Sialic acid has a very important and unique role. Previous studies have shown this terminal sugar necessity in spermatogenesis, sperm maturation and fertilization.Therefore we decided to determine Sialic acid normal distribution in testicular cells by means of lectin histochemistry and peroxidase labelled Weat germ agglutinin (WGA) lectin, specific for Sialic acid.The pathological states due to different agents could be assessed in comparison with a normal staining pattern. Results show an increase in sialic acid contents from spermatogonia to spermatid formation that followed by sudden reduction in early spermatids. Again in later steps of spermiogenesis to sperm maturation it elevates.There is a moderate and strong reaction in sertoli and leydig cells respectively.These results mean that sialic acid may mask the receptors or cell surface antigens and/or play itself such as a specific receptor in spermatogonial differentiation and meiosis. Elevation of sialic acid in spermiogenesis and mature sperm, rather than a receptor, is related' to its role in masking of sperm surface antigens. In leydig cells sialylated glycoconjugates perhaps act such as a testosterone binding structures that transfer it to blood streem and seminiferous tubules.      

Zinc (Zn) is a trace element which is incorporated into the structure of a variety of cells, hormones and many enzymes. This study was designed to characterize the prolactin status of male and female rats developed during the period of acute and subacute Zn administration. In acute experiments, Zn was administered at doses of 25 and 50 mg/kg; i.p. in 6 rats per group. In subacute experiments, Zn was administered daily for 12 and 16 days at a dose of 15 mg/kg i.p. to 15 rats in each group. Control animals received normal saline during the treatment regimen. Both control and Zn treated rats were anesthetized with ether and then sacrificed by decapitation. Blood samples were obtained from each animal after decapitation and prolactin level of 6 rats in each group were measured by RIA. Zinc at doses of 25 or 50 mg/kg caused a significant reduction in serum concentration of prolactin in female rats. However, in male rats, significant decrease in prolactin level was observed only with 50 mg/kg zinc administration. Subacute administration of zinc acetate (15 mg/kg/day for 12 or 16 days) caused a significant reduction in serum prolactin level in both male and female rats compared with the controls. It is concluded that large doses of zinc could result in marked changes in the concentration of prolactin.      

Neuropathic pain is a chronic pain which is produced as a result of peripheral nerve damage and causes hyperalgesia (increased sensitivity to noxious stimuli). Gender differences to neuropathic pain have been reported in animal models but the results are controversial. So in this study the gender differences to noxious stimuli and hyperalgesia process are studied in mice using Partial Sciatic Nerve ligation (PSNL) model during 20 days. The response to painful stimulus is tested by Hot plate method in 3 groups of intact, sham- operated and PSNL male and female mice and the reaction time was recorded in intact group. In sham- operated and PSNL groups the reaction time to thermal stimulus was also recorded every other day from 6 to 20 days after operation. The results of this study showed that the mean reaction time to thermal stimuli was not significantly different between intact and sham- operated mice. But in PSNL mice the mean reaction time decreased significantly in comparison with intact and sham- operated groups. The mean reaction time to thermal stimuli in PSNL female mice was significantly different from sham- operated groups in 10th and 14 th days after operation. While in male PSNL mice the reaction time was significantly different in 10th day after operation. Hyperalgesia in female mice was continued from 10 to 14 days after operation but in male PSNL mice the hyperalgesia was only observed on 10th day after operation. In summary the results of this study showed that the partial sciatic nerve ligation caused hyperalgesia in both sexes but the female mice are better models for studying hyperalgesia process. The reason for gender difference to neuropathic pain following partial sciatic nerve ligation is not determined yet.      

Starting from 1-benzyl-2- mercapto-5-hydroymethylimidazole which is prepared readily, a series of novel 2-(2-alkylthio-l-benzyl-5-imidazolyl) -2,3,4- trihydro-5- imino- 1,3,4- thiadiazoles [4a-c] were synthesized through multiple steps. The anticonvulsant activities of the title compounds [4a-c] were studied id mice in order to identify more potent anticonvulsant agents. In maximum electroshock test except 4a other compounds [4b,c] decreased the duration of tonic seizures. These results indicate that they may have beneficial effects in grand mal seizures, but their potency, compared with diazepam was very lower.