Stem cell transplantation and functional recovery after spinal cord injury: a systematic review and meta-analysis / 대한해부학회지

Spinal cord injury is a significant cause of motor dysfunctions. There is no definite cure for it, and most of the therapeutic modalities are only symptomatic treatment. In this systematic review and meta-analysis, the effectiveness of stem cell therapy in the treatment of the spinal cord injuries in animal models was studied and evaluated. A systematic search through medical databases by using appropriate keywords was conducted. The relevant reports were reviewed in order to find out cases in which inclusion and exclusion criteria had been fulfilled. Finally, 89 articles have been considered, from which 28 had sufficient data for performing statistical analyses. The findings showed a significant improvement in motor functions after cell therapy. The outcome was strongly related to the number of transplanted cells, site of injury, chronicity of the injury, type of the damage, and the induction of immune-suppression. According to our data, improvements in functional recovery after stem cell therapy in the treatment of spinal cord injury in animal models was noticeable, but its outcome is strongly related to the site of injury, number of transplanted cells, and type of transplanted cells.

Decrease in cavity size and oligodendrocyte cell death using Neurosphere-Derived oligodendrocyte-like cells in spinal cord contusion model

Background: Oligodendrocyte cell death is among the important features of spinal cord injury, which appears within 15 min and occurs intensely for 4 h after injury, in the rat spinal contusion model. Accordingly, the number of oligodendrocytes progressively reduced within 24 h after injury. Administration of oligodendrocyte-like cells [OLCs] into the lesion area is one of the approaches to counterbalance this condition

Methods: Bone marrow stromal cells were transdifferentiated into neurospheres and then into neural stem cells and later were differentiated into OLCs using triiodothyronine and transplanted into the spinal cord contusion rats. The postinjury functional recovery was explored and compared with the control group using Basso-Beattie-Bresnahan and narrow beam behavioral tests. At the end of 12th week, spinal cord segments T12-L1 were histomorphologically studied by immunohistochemistry

Results: Motor improvement was more obvious during 2nd to 4th weeks and got less prominent during 4th to 12th weeks. Histomorphometric findings indicated that cavity formation decreased in epicenter of transplantation area in experimental groups in comparison with the control groups

Conclusion: The findings obtained in the present study showed that OLC therapy is a potential approach in the treatment of spinal cord traumatic injuries

[ effects of hydro-alcoholic extracts of aerial components of Teucrium polium on pressure ulcer healing process and tensile strength in Wistar rats]

Wound healing represents a dynamic physiological process influenced by many factors. The aim of the present study was to evaluate the effects of hydro-alcoholic extracts of aerial components of Teucrium polium on the tensile strength in rat. Twelve Wistar rats were randomly divided into two equal [n= 6] treatment and control groups, pressure ulcer were made over the dorsal thoracic region according to the shyn model. Animals were treated with topical hydro-alcoholic extracts of aerial components of Teucrium polium twice a day post surgery until complete healing was achieved. Tensiometry were then studied. No significant difference in biomechanical parameters was observed among the ointment containing of extract 1%, vehicle and control groups. This study shows that topical application of Teucrium polium. Aerial components of Teucrium polium did not have any effect on healing of pressure ulcer in an animal model. Further studies are requiring for assessment of other extracts by different solvents of this plant on pressure ulcer wound healing

Mesenchymal stem cells as an alternative for schwann cells in rat spinal cord injury

Spinal cord has a limited capacity to repair; therefore, medical interventions are necessary for treatment of injuries. Transplantation of Schwann cells has shown a great promising result for spinal cord injury [SCI]. However, harvesting Schwann cell has been limited due to donor morbidity and limited expansion capacity. Furthermore, accessible sources such as bone marrow stem cells have drawn attentions to themselves. Therefore, this study was designed to evaluate the effect of bone marrow-derived Schwann cell on functional recovery in adult rats after injury. Mesenchymal stem cells were cultured from adult rats' bone marrow and induced into Schwann cells in vitro. Differentiation was confirmed by immunocytochemistry and RT-PCR. Next, Schwann cells were seeded into collagen scaffolds and engrafted in 3 mm lateral hemisection defects. For 8 weeks, motor and sensory improvements were assessed by open field locomotor scale, narrow beam, and tail flick tests. Afterwards, lesioned spinal cord was evaluated by conventional histology and immunohistochemistry. In vitro observations showed that differentiated cells had Schwann cell morphology and markers. In this study, we had four groups [n = 10 each]: laminectomy, control, scaffold and scaffold + Schwann cells. Locomotor and sensory scores of cell grafted group were significantly better than control and scaffold groups. In histology, axonal regeneration and remyelination were better than control and scaffold groups. This study demonstrates that bone marrow-derived Schwann cells can be considered as a cell source for Schwann cells in SCI treatment

[Morphological changes in hippocampus CA1 neurons after nicotine administration in rats]

Previous studies have shown morphological changes after intra peritoneal drug administration in human and animals. This study examines the effect of intrapretoneal nicotine administration in pyramidal neurons in area CA1 of hippocampus. The study included male Wistar rats with the mean weight of 220-250 g. Nicotine was administered at the dose of 0.4 and 1.5 mg/kg, each for a period of three days. The animals were then anesthetized using ketamine [70 mg/kg]. After being fixed through transcardiac canula with formalin 4% and bafer phosphate 6, the brains were sectioned and stained using Golgi's staining technique. Using MOTIC software, they were then examined for histological evaluations. Data were analyzed using unpaired t-test. Our results showed a decrease in the size and the number of pyramidal cells in area CA1 of hippocampus for the nicotine group. While the number of dendrites was fewer in experimental group, asteocytes had increased in comparison to the control group. Our study indicates the nicotine administration results in a significant reduction in the size of pyramidal cells in area CA1 of hippocampus

[ effect of spatial learning on the number of astrocytes in the rat's dentate gyrus]

Dentate gyrus is a part of hippocampal formation that plays an important role in memory and learning. Astrocytes are one of the important glial cells in nervous tissue that play a more active role in neuronal activity, including regulating ion flux currents, energy production, neurotransmitter release, and synaptogenesis. The aim of this study was to determine the spatial memory effect on the number of astrocytes in Rat's dentate gyrus. This experimental study, was done on 18 male Wistar Rats with using Morris water maze and Reference and Working memory methods. After spatial learning the Rat's brains was carried out and histological preparation was carried out, the slices were with PTAH method. The data analyzed, using T-test and One-way ANOVA. The results showed significant difference in astrocytes number in dentate gyrus area between Reference memory [300.57 +/- 5.98] and control [73.73 +/- 22.61] groups [P<0.05]. The difference between working memory [375.77 +/- 4.11] and control groups was significant. Comparing two groups there was a significant difference of number of astrocytes cell between the working memory and Reference memory group [P<0.05]. This study showed that spatial learning such as Reference memory and Working memory increase the number of astrocytes in dentate gyrus and this increase can be due to duration of learning

[ effect of reference memory on the number of astrocytes in different subfield of rat's hippocampus]

In addition to pyramidal neurons and interneurons, the hippocampus contains Astrocytes that play important roles in regulating ion flux currents, energy production, neurotransmitter release and memory. Learning needs some instrument for information storage and information maintenances mechanisms resemble to memory. The aim of this study was determination of spatial memory effect on the number of astrocytes in rat's hippocampus. In this experimental study, with usage of Morris Water Maze and Reference memory technique, we used 10 male albino wistar rats. 5 rats were in control group and 5 rats in Reference memory group. After histological preparation, the slides were stained with PTAH staining for showing the Astrocytes. The findings of this study showed significant difference in astrocytes number in CA1, CA2 and CA3 area of hippocampus between control and reference memory group. The mean and SD of astrocytes in CA1, CA2 and CA3 of reference memory group were 118.57 +/- 25.29, 58.91 +/- 23.59 and 116.6 +/- 31.14, that they are more than control group with 49 +/- 17.29 in CA1, 48.8 +/- 25.21 in CA2 and 41.95 +/- 11.22 in CA3. We concluded that the number of astrocytes increased due to spatial learning [e.g. reference memory method]