جستجوی مقالات مرتبط با کلیدواژه « stereology » در نشریات گروه « دامپزشکی »

The pollution of environment with heavy metals following the increase in the industrial production has created problems in the lives of living organisms. Lead can penetrate the soft organs of body, and by depositing in them can cause disorders their function. Lead can cross the blood-placental barrier and transfer to the fetus. It is also possible to pass lead through milk to the newborn.

The stereology approach was used in rats as animal models to examine the impact of low dosage lead contamination in the mother on the average volume of follicular oocytes and the average volume of mature follicles.

Wistar rats were randomly divided into five groups, which included a control group and four experimental groups of pre-pregnancy, pregnancy, lactation and pre-pregnancy-pregnancy-lactation. The control group had access to drinking water with 0.5 ml of glacial acetic acid. Experimental groups administered lead acetate at a rate of 0.2 percentage + 0.5 ml of glacial acetic acid through drinking water in different periods (pre-pregnancy group 30 days before mating, pregnancy group 21 days of pregnancy, lactation group. They received 21 days of lactation and the pre-pregnancy-pregnancy-lactation group 30 days before mating until the end of lactation). On the 65th day after birth, all infants were killed in the laboratory and left ovary specimens were collected for stereological studies.

The results showed that the average volume of oocytes in the primordial, monolayer primary, multilayer primary, and antral follicles increased in the lactation group compared to the control group and other experimental groups (P<0.05). Furthermore, the mean volume of primordial and monolayer primary follicles in lactation group increased compared to the control and experimental groups (P<0.05).

This study's results showed that maternal exposure to low doses of lead during lactation increases the average volume of oocytes and increases the average volume of growing follicles.

Spinal cord injury (SCI) is a disabling neurological condition. In this study, first, the total volume of the thoracic spinal cord of healthy rats was calculated using stereology. In the next step, the volume of the thoracic spinal cord in the T9 area, the volume of the gray matter, white matter, vacuole, scar, and the locomotor function of animals after SCI were calculated. Erythropoietin (EPO) is a glycoprotein that protects cells in various tissues, including the spinal cord, by activating multiple signaling pathways. This study aimed to investigate the role of chitosan alginate hydrogel containing EPO on SCI. We observed that injured rats receiving EPO had improved functional recovery as assessed by the BBB Locomotor Rating in compared sham and negative control groups. Stereological estimates of the thoracic region show that the total volume of gray and white matter in the thoracic region of the rat averaged 126.2886 and 295.1914 mm3, respectively. The mean obtained from the dorsal horn in the thoracic part of the rat was 52.35028 mm3, and the abdominal horn was 60.79638 mm3, or in other words, the mean total volume of the thoracic spinal cord in the rat was 514.06 mm3. In the groups treated with a hydrogel, the amount of vacuole and scar in the spinal cord tissue was significantly reduced compared to the negative control group. Hydrogels containing EPO (1000 IU/kg) can significantly improve the tissue repair of the spinal cord at the injury site.

With the expansion of industrial processes, heavy metal pollution for example lead has become a serious problem. they have the ability to pass through organs and causes them to malfunction. One of the target organs of lead is ovarian tissue. Lead is also able to cross the blood-placental barrier and transferred to the fetus. It is also possible to pass lead through milk to the newborn. This study was performed to investigate the effect of low dose mother's lead Consumption on the development of the ovaries using stereology technique in rats as animal models. In the present study, Wistar rats were randomly divided into five groups. The groups included the Control group and 4 experimental groups of Pre-pregnancy, Pregnancy, Lactation and Pre-pregnancy-pregnancy-lactation. The experimental groups received 0.2% lead acetate, with 0.5cc glacial acetic acid– through drinking water. Acetate consumption was in such a way that in the pre-pregnancy group 30 days before mating, in the pregnancy group during 21 days of pregnancy, in the lactation group during 21 days of lactation, and in the pre-pregnancy-lactation group from 30 days before mating to the end of lactation they received lead acetate through drinking water. On the 65th day after the birth, all infants were killed in the laboratory and left ovarian specimens were collected for stereological studies. Examination of the results showed that the total volume of ovary, cortex, medulla, interstitial tissue and total volume of adult reproductive follicles were not significantly different between the experimental groups of pre-pregnancy, pregnancy, lactation and pre-pregnancy, pregnancy-lactation and the control group. Examination of the corpus luteum volume results showed that the pre-pregnancy group had a significant decrease compared to the pregnancy group. The present study showed that exposure of mothers to low-dose lead acetate reduces the volume of corpus luteum, especially during pre-pregnancy.

The length and structure of the transitional zone in the tunica media in the renal artery of adult male cats were investigated. In addition, the volume of the lumen and different layers in transitional and non-transitional zones in the right and left sides were also determined. Morphometrical, histological and stereological studies were performed on 16 renal arteries of 8 adult male cats. After perfusion and morphometrical measurement, routine tissue processing was carried out by autotechnicon. The processed tissues were embedded in paraffin and sectioned serially into 5 μm thickness. The sections were stained with haematoxylin and eosin and orcein. In the morphometrical measurement, the right renal arteries were longer than the left ones with a mean value of 22.0 ± 0.2 and 18.8± 0.1 mm, respectively. Despite the fact that the right renal artery is commonly longer, the length of transitional zone was 7 mm in both renal arteries of adult male cats. The artery has a structure between muscular and elastic type at its origin with several elastic layers in the tunica media which is gradually changed to a muscular type at the distal section after 7 mm from origin of aorta. Transitional zone has an arrangement of parallel elastic fibers which become rare and fragmented towards the non-transitional zone. The volume of tunica intima, tunica media, tunica adventitia and lumen of the artery decrease from transitional zone towards the non-transitional zone and the volume of these areas in both transitional and non-transitional zones in the right renal artery is more than the left one. The volume of the lumen in transitional zone differs significantly compared to non-transitional zone, in both sides (P<0.05). Also there is a significant difference in the volume of the lumen in non-transitional zone between right and left renal arteries (P<0.05).