Effects of maternal diazinon exposure on frontal cerebral cortical development in mouse embryo.

BACKGROUND: Diazinon including organophosphate (OP) that is widely used in agriculture and animal husbandry industry and the risk of human infection with the toxin and their toxicity. METHODS: Pregnant balb/c mice (30-35 g) were randomly divided into five groups of five: the control group (no intervention), two sham groups (emulsifier 0.52, and 5.2 liters/volume). From the seventh to the eighteenth day of pregnancy, two experimental groups received diazinon inhaled 1.3 (EXP1) and 13 liters/volume (EXP2) for 40 min every other day, respectively. On the 18th day of pregnancy, the animals were killed and their embryos were removed to appraisal the growth of fetus and development of the frontal cortex. A computer-assisted morphometric quantitative images analysis were performed on the frontal cerebral cortex (FCC) including cortical plate (CP), intermediate zone (IZ) and matrix (proliferative) zone (MZ) of the mouse embryos. FINDINGS: The average of crown-rump length and weight of the embryos in the experimental groups were increased without any significant difference. The mean fetal FCC thickness in the EXP2 group was significantly reduced compared to the control group, CP thickness was remarkably increased in fetuses exposed to diazinon. Comparing the mean thickness of MZ and IZ in EXP groups with the sham and control groups indicated a significant decrease. The positive K-67 cells in the FCC of the EXP2 group were significantly reduced. DISCUSSION: Exposing diazinon during pregnancy can reduce brain development and would be neurotoxic to the developing brain and can lead to behavioral changes in the offspring.

Modified PLGA nanofibers as a nerve regenerator with Schwann cells.

Polylactide-co-glycolide acid (PLGA) is known as a biodegradable and biocompatible polymer. This polymer has been highly used in tissue engineering. In this study, the biological behavior of Schwann cells (Rat) was investigated in co-culture with L lysine/gelatine coated PLGA nano-fiber. In this study, PLGA was dissolved in a hexafluoro propanol based solvent and nanofiber prepared by an electronic method. They were coated with gelatin and poly-L-lysine individually. These polymer properties were investigated by Scanning Electron Microscopy (SEM) analysis and contact angle measurement. After extraction of rat Schwann cells, the cells were cultured in three groups of nano-fiber; nano-fiber PLGA, nano-fiber gelatine coated PLGA and nano-fiber poly-L-lysine coated PLGA. Cell death and Cell proliferation were evaluated by Acridine orange staining (living cell with a green nucleus and dead cell with an orange nucleus) and morphology was investigated by SEM in 2, 4 and 6 days. The diameter of electronic nanofiber PLGA was between 270 to 700 nm. Average contact angles of PLGA, PLGA coated with gelatine, coated with poly-L-lysine and PLGA were 40.12, 64.58 and 107.66degrees, respectively. The findings showed a significant reduction of cell proliferation in PLGA nanofiber ( it was important than PLGA without nano-fiber (P <0.05)). But, this amount was increased in nanofiber which coated with poly-L-lysine and gelatine. PLGA nanofiber-poly-L-lysine was more biocompatible than PLGA nanofiber-gelatine and this comparison was done with rat Schwann cells.

A model portraying experimental loss of hair cell: the use of distortion product otoacoustic emission in the assessment of rat's ear.

The use of rats in research academies to study deafness is widespread, meanwhile medicinal methods to eliminate hair cells is also increasing. Thus, aminoglycosides and loop diuretics have grasped more attention. This study aimed at establishing an animal model in which a rapid distortion of the hair cell of cochlea administering amikacin and furosemide and using distortion product otoacoustic emission (DPOAE) the functioning of rat's ear would be assessed. Forty-eight male Sprague-Dawley rats (mean weight 200-250g) were randomly divided into six equal groups. Except the control group the rest received 0.5mg/g, 0.75mg/g, 1mg/g, 1.25mg/g, and 1.5mg/g, of subcutaneous amikacin respectively. 30 minutes later every rat received 0.1mg/g of furosemide intrapritoneally. DPOAE of rats was measured before these injections and 72 hours later. Then tissue sections of the rat's cochlea were prepared. All the cases had a significant decrease in their DPOAE with the frequencies 2KHz-8KHz (p<0.05). The most change in DPOAE was in rats which had received 1mg/g - 1.5mg/g amikacin. Histological studies approved distortion of hair cell even the apical turn. To establish a deafness model due losing hair cells, it is possible to use a combination of 1mg/g amikacin and 0.1mg/g furosemide. Besides, to approve deafness DPOAE resulted can be used.

In vitro differentiation of bone marrow stromal cells into oligodendrocyte-like cells using triiodothyronine as inducer.

An in vitro technique was devised to induced autologous adult stem cells into oligodendrocyte-like cells. In this study, a protocol was developed for the induction of bone marrow stromal cells (BMSCs) into oligodendrocyte-like cells. BMSCs were incubated in one of these three pre-inducers: dimethyl sulfoxide (DMSO), ß-mercaptoethanol (ßME) or biotylated hydroxyanisol (BHA), each followed by retinoic acid (RA) treatment. The percentage of viable cells in BHA-RA preinduced cells was significantly lower than the others. The results showed that the preinduced cells were immunoreactive for nestin and NF-68; among the mentioned protocols, the immunoreactivity yielded by following the DMSO-RA protocol was significantly higher than the others. Moreover, no significant immunoreactivity was observed for preinduced cells to O4, O1, MBP (myelin basic protein), S100, and GFAP (glial fibrillary acidic protein). The cells were immunoreactive to oligo-2. Two phases of induction were done: the first was a combination of basic fibroblast growth factor (bFGF), platelet-derived growth factor (PDGF) and heregulin (HRG), followed by either triiodothyronine (T3) or Forskolin (FSK) as the second phase. The conclusion is that the trans-differentiation of BMSCs by DMSO followed by RA (preinduction stage) then bFGF-PDGF-HRG followed by T3 (10 ng/ml) (induction stage) can be a potential source for oligodendrocyte-like cells preparation.

Effects of maternal oral morphine consumption on neural tube development in Wistar rats.

Opiate abuse during pregnancy may result in abnormal nervous system function. In order to evaluate the effects of morphine on the development of the nervous system, the present study focused on the effects of maternal morphine consumption on neural tube development in Wistar rats. Female Wistar rats (250-300 g) were crossed with male rats and coupling time was recorded (embryonic day 0-E0). Experimental groups received 0.1, 0.05, and 0.01 mg/ml of morphine in drinking water daily (14 ml water for each rat). Control group received tap water. On embryonic day 9.5 (E9.5), the animals were anesthetized and the embryos were surgically removed. The embryos were fixed in 10% formalin for 1 week. After this time, weights and lengths (antero-posterior axis--A-P) of the embryos were determined and then tissues were processed, sectioned, and stained in hematoxylin and eosin (H&E). The sections were investigated for neural tube development by light microscope and MOTIC software. The decrease in "A-P" length and embryonic weight for the group that received 0.01 mg/ml morphine was significant. It seems that daily consumption of morphine sulfate could delay neural tube development. In addition, administration of 0.01 mg/ml of morphine led to damage to the regulated neuro-ectoderm layer and its thickness. This study showed that oral morphine consumption leads to neural tube defects, as indicated in the morphometric change and also reduction in weight and length of the embryos. These defects might affect the behavior of the animals.

Prophylactic ophthalmic bethametazone for sulfur mustard-induced ocular injury.

BACKGROUND: The present study sought to evaluate the prophylactic effect of bethametazone on sulfur mustard (SM)-induced ocular morphometric damage in the rabbit eye. METHODS: Twenty five healthy New Zealand white rabbits were divided into 4 groups of normal (not exposed to SM or solution), solution (exposed to solution), SM (exposed to SM), and prophylactic bethametazone (received eye solution of bethametazone then exposed to SM solution; then treated for 2 weeks). On the day 14 after exposure, five-micron sections were stained with haematoxylin and eosin for light microscopy evaluation. The ocular morphometric characteristics in the study groups were compared to determine the prophylactic effects of the bethametazone. RESULTS: Bethamethazone could protect eyes from SM effect by means of decrease in changes in number of Keratocyte in 10000 µm(2), thickness of cornea (µm), thickness of corneal epithelium (µm), number of meibomian gland's cells in 2500 µm(2), thickness of palpebral conjuctival epithelium (µm), thickness of epithelial of palpebral skin (µm), number of epithelial layers of palpebral skin, and number of goblet cells in conjunctival sac in 1000 µm. CONCLUSIONS: Bethametazone may have a prophylactic effect on the early lesions of the eye of the rabbit due to SM exposure.

Effects of maternal oral administration of morphine sulfate on developing rat fetal cerebrum: a morphometrical evaluation.

Intrauterine morphine exposure is a risk factor for neurological and behavioral deficit in children, although the precise underlying biological correlate for this is unclear. Female pregnant rats were orally treated with 0.1 mg/ml of morphine solution on the 21st day of gestation. Pregnant rats were killed on the 21st day of gestation and their fetuses were taken out and evaluated for growth and cerebral development. The fetuses were fixed and followed by dehydration through graded ethanol solutions and were then embedded and their heads were coronally sectioned through the frontal cerebral cortex. Quantitative computer-assisted morphometric study was done on the frontal cerebral cortex (FCC) which consists of cortical plate (CP), intermediate (migratory) zone (IZ) and matrix (proliferative) zone (MZ) in the rat embryos. The results showed that morphine exposure caused a significant reduction of fetal weight and crown-to-rump length in morphine exposure group. The present study showed that animals with intrauterine morphine exposure, induced by a period of reduced placental blood flow during the second week of pregnancy, demonstrate reduced both cortical thickness and the numbers of neurons in the developing fetal frontal cerebral cortex (FCC). Histomorphometric evaluation revealed that the thickness of the CP was significantly decreased in the morphine-exposed embryos. In addition, neuronal counting showed that cell proliferation in the CP was suppressed after morphine administration and that the migration of neurons from the matrix zone (MZ) to the cortex was decelerated. In conclusion, these results showed that morphine exposure during the second week of pregnancy could affect brain development in a way, which could lead to neurological and behavioral deficits in the postnatal animal.