Assessment of in vitro maturation and fertilization of BDF1 mice germinal vesicle oocytes with and without cumulus cell after vitrification

Improving pregnancy rate associated with the use of cryopreserved oocytes would be an important advancement in human Assisted Reproductive Technology [ART]. Vitrification allows glasslike solidification of a solution, a physical process, without ice crystal formation in the living cells. The purpose of this study was to evaluate the viability of the oocytes, in vitro maturation and embryo development vitrified germinal vesicle oocytes after single and stepwise exposure to cryoprotectants. Germinal vesicle oocytes or without cumulus cells were transferred to a verification solution composed of 30% M sucrose [v/v] ethylene glycol, 18% [w/v] Ficoll-70, and 0.3 M sucrose either by single step or in a step-wise fashion. After verification and storage in liquid nitrogen, the oocytes were thawed and washed twice in the medium TCM 119 and then subjected to in vitro maturation, the capacity of fertilization and embryonic development to 2-cell were examined in vitro. The oocytes surviving, maturing to MII, fertilization developmental rate in the step-wise exposure were significantly higher [P<0/05], compared with the corresponding rate in single step procedure. The results of the present study indicated that oocytes vitrified with cumulus cells and stepwise procedure had a positive effect on the maturation and developmental rate than oocytes without cumulus cells and single step procedure

[ effect of guidance channel on sciatic nerve repair in adult rats]

Peripheral nerve lesions are a challenge for neurosurgeons and different surgical repairing methods are applied for the treatment of this problem. This study was conducted to evaluate the poled polyvinelidene fluoride [PVDF] tube filled with nerve growth factor [NGF] and collagen gel as a substitute for nerve autograft. In this experimental study the left sciatic nerve was manipulated in 50 male Wistar rats and then the animals were divided randomly into five groups. In the epineural group the injured nerves were repaired by end to end suture. In the rats with autograft a 10 mm piece of sciatic nerve was rotated through 180 and sutured in the nerve gap. In the nerve guidance channel group [NGC], polarized piezoelectric PVDF tube containing NGF and collagen gel was replaced in the gap and in the axotomy group two nerve ends were hidden among muscles. The left sciatic nerve was exposed but not transected in the sham group. After two months L4-L6 segment neurons of spinal cord were studied histologically and by immunohistochemical and axonal DiI tracing. The collected data were analyzed by one way ANOVA, LSD and paired t-test. The mean number of Bax positive cells and labeled motor neurons increased significantly in axotomy and sham group respectively, compared to the other groups [P<0.05]. Also, the mean number of labeled motor neurons increased significantly in epinural group in comparison to the autograft and the NGC groups [P<0.05]. There was no significant difference in the mean number of the labeled neurons between the autograft and nerve guidance channel groups. The mean number of motor neurons in the left side showed a significant decrease in comparison to that of the right side [p<0.01]. The PVDF tube together with other therapies provided a favorable environment for nerve regeneration and could be used as a substitute for autograft in nerve injuries

[Effects of ascorbic acid on the amplitude of ventral tegmental area field action potential in morphine-exposed rats [an electrophysiology study]]

Evidences have indicated that the Ventral Tegmental Area [VTA] is the major source of dopamine [DA] neurons projecting to cortical and limbic regions involved in cognitive and motivational aspects of addiction. Also, studies have indicated that the Ascorbic acid [vitamin C] can reduce the dependency symptoms of opioids such as morphine via effect of activity on dopaminergic neuron in VTA. For this reason, the aim of this study was to assess the effects of ascorbic acid on the amplitude of Ventral Tegmental Area field action potential in morphine-exposed rats. Forty male Wistar's rats were used in this experimental study conducted at Yasuj University of Medical Sciences in 2010. Animals were randomly divided into four groups after electrode implantation and recovery period: 1. No- Vit C and No-Addicted group [nVitC.nA] 2. Vit C and No-Addicted group [VitC.nA] 3. No- Vit C and Addicted group [nVitCA] 4.Vit C and Addicted [VitC.A], The Vit C groups received 500 mg/kg of Vit C during 20 days. For addicted groups morphine was administrated once daily for 20 days. In the 20[th] day, the field potential recording was accomplished. Two-way ANOVA was used for data analysis followed by the Tukey test for post hoc analysis. Results were considered significant at P<0.05. This study shows the exposure to morphine declined the power of Delta and Beta bands [p<0.05] and Vit C solely enhance power of Theta and Beta [p<0.05, p<0.001] in VTA nuclei. Furthermore, Vit C could alter power of some bands which were affected by morphine. Therefore, it seems that Vit C has an increasing effects on them [p<0.05]. Although the effect of Vit C on power of the VTA bands is not well known, but it is supposed that this phenomenon can be related to alteration in activity of dopaminergic neuron in the brain

[Histomorphology of the olfactory mucosa and spinal tissue sparing following transplantation in the partial spinal cord injury in rats]

Nowadays, cellular and tissues transplant has become the focus of attention for spinal cord injury. It has been shown olfactory nerve cells or olfactory mucosa whi have more efficient on nervous tissue repair and they have been more studied in experimental study. Furthermore, they were used in a few clinical centers for spinal defect. But mucosa tissue and spinal tissue have different structure and there is doubt about the integration of mucosa tissue in nervous tissue. Thus, in this research the morphology and the effect of the fetal olfactory mucosa [FOM] on spinal tissue sparing were studied after transplanted into the spinal cord hemisection in rats. This experimental study was conducted at Iran university of Medical Sciences in 2008. Of thirty eight female Sprague-Dawley [200-250g] rats twenty- eight were spinally hemisected at the L1 spinal level and were randomized into two groups of 14 animals. Treatment group received FOM graft and the control received fetal respiratory mucosa graft [FRM]. The other animals received surgical procedure without spinal cord injury as a sham group. The morphology of the transplant region and spinal tissue sparing was examined histological eight weeks after transplantation. The collected data was analyzed by the SPSS software using ANOVA and the morphology of the transplant region were studied by light microscope. Histological study showed that the both mucosa tissues could not integrate with the parenchyma of the spinal tissue. Although the FOM were fused more then the FRM with the host tissue but clear boundary was seen at the graft-host interface. The mean spinal tissue sparing of the treatment group increased a little compare to the control but a significant difference was not apparent whereas, the spinal tissue sparing in treatment and control groups compare to the sham group decreased significantly [P <0.05]. Transplantation of the mucosa tissue directly, into the spinal cord injury was created different cytoarchitecture with spinal tissue and FOM partially preserving tissue sparing

[ effect of silybum marianum on GFAP and spatial memory in a mouse model of alzheimer's disease]

Studies have shown that Silybum marianum have high levels of antioxidant polyphenolic substances and have neuro-protective effects on neurodegenerative diseases. Accordingly, this study was conducted to determine the possible effect of Silybum marianum on expression of and spatial memory in a mouse model of Alzheimer's disease. This experimental study was conducted at Yasuj University of Medical Sciences in 2009. Thirty adult male Wistar rats were allocated in three groups: sham group, experimental group, and lesion group, each consisting of ten rats. The experimental and lesion groups received Ibotonic acid of the NBM nucleus in stereotaxic apparatus whereas the sham group underwent surgical procedure without any injection. The experimental group received 200mg/kg of Silybum mirianum extract orally, diluted in 1% Arabic gum. Also the sham group received 1% Arabic gum every day for four weeks. The lesion group did not receive anything. The behavioral assessment was measured, after treatment, by using of Y maze test on day 7 and 28 in all groups. The ELISA method was used to measure the GFAP level in Hippocamp at the end of behavioral assessment. The collected data was analyzed by the SPSS software using ANOVA and Repeated Measures of Analysis Variance tests. Improvement of behavioral performance of the experimental animals compared to the lesion and sham groups were increased significantly on day 7 and 28 [P<0.01 and P<0.001 respectively]. The ELISA method showed that the level of the GFAP synthesis decreased in the experimental group compared to the lesion and sham groups [P<0.001]. The Silybum marianum plant has a protective effect on the nerve tissue in a mouse model of Alzheimer's disease by decreasing of the GFAP synthesis and lead to the improvement of behavioral performance

[Effects of GLP-1 on y-aminobutyric acid and serotonin metabolism in synaptosomal fractions from rat hypothalamus and brain stem]

Background: glucagons - like peptide-] [7-36] amide [GLP-1] is the main product of the glucagon gene expression in intestinal L cells. GLP-1 is released from the intestine into the circulation in response to the ingestion of food and is the most potent stimulator of glucose-induced insulin secretion. GLP-1 receptors have also been detected in discrete areas of rat brain and intracerebral ventricular injection ofGLP-1 has been shown to inhibit feeding in fasted rats

Methods and Materials: this study is an in vitro study. Used rats are male and their weight is 200 to 220 grams and each group has 7 rats. In this study HPLC techniques were employed to evaluate the effects of GLP-1 on monoamine metabolism in rat brain as a neuropeptide. Synaptosoms were prepared from homogenates of combined hypothalamus and brain stem from rats in each group. The synaptosomal pellets incubated for 15 minutes in ashaker bath at 3 7 C. The effect ofGLP-1 on Synaptosoms was tested by adding 50 pL qj"GLP-1 5x10-7 M to the incubation medium. For this group a control group was prepared by adding normal saline instead of GLP-1. The data were analyzed by T- test

Results: CLP-I decreased levels of serotonin [5-HT] by 20% [P<0. 05] after 15 minutes of incubation with combined hypothalamus and brain stem Synaptosoms. Level of 5- hydroxyindolacetic acid [5-HIAA], the principal metabolite of 5-HT, and tryptophan, the amino acid precursor of 5-HT decreased by 21% and 37 %[ P<0.05] respectively. Gamma-Aminobutyric acid [GABA] and its amino acid precursor glutamic acid [Glu] were both quantities at the same conditions as above, but an operculum derivatization HPLC technique was used. The increase levels of GABA [14%] and Glu [6%] by GLP-1 was not significant

Conclusions: the results suggest that decreased synaptosomal levels of 5-HT and 5-HIAA caused by GLP-1 are due to diminished availability of' tryptophan by the neuropeptide