Journal of Stem Cells最新文献

Background and objective: Around 20% of fractures have impaired or no healing. Many procedures have been tried with varying success. The objective of this study is to assess effect of osteoblast transplant (obtained after proliferation and differentiation of MSCs of bone marrow aspirate) in healing of experimentally created non-union of femur in rats.

Methods: Non-Union of femur were created in Sprague-Dawley rats weighing 200-250 grams. In 20 rats, Femur fracture was surgically created in 20 rats and 2 mm of the periosteum was cauterized on each side of the fracture and this created a non-union in 8 weeks. In 10 animals bone marrow was aspirated from the femoral shaft using 24-gauge butterfly needle and injected in special media. The two groups 10 each were marked and animals were kept in the similar surroundings. After radiological confirmation of non-union at 8 weeks, an injection containing 1 x 10 (6) osteoblasts cells (1 million cells) dissolved in 200 microliters of balanced salt solution was injected at the nonunion site. In the control group of 10 rats 1 ml of normal saline was injected. In 5 animals of each group the fracture was fixed using 1 mm kirschner wire and the other 5 were treated without fixation. After 8 weeks of implantation the animals were radiographed and euthanized. The hind legs were disarticulated from the hip joints, specimens were stored in 2% formalin and histological evaluation was performed.

Results: There were no deaths in both the groups and there was one superficial infection in the control group. Eight weeks post implantation of the BM-MSCs derived osteoblasts, all the fractures of the study group united with robust mineralization and new bone formation confirmed by radiograph and histopathology. In the control group there was no healing and the histopathology showed full of fibrous tissue with cartilage cells lining the fracture site.

Conclusions: In conclusion, our results indicate that implant of BM-MSCs derived osteo-progenitor cells at the non-union efficiently induces a complete union. We believe a similar study should be carried out in a larger animal before any human trials.

Age-related macular degeneration (AMD) is a leading cause of vision loss and blindness in the elderly. The dry form is more common and accounts for about 85-90% of AMD patients in US, while Japanese AMD patients predominantly progress to wet-form or polypoidal choroidal vasculopathy (PCV). Recent studies have shown HTRA1, a serine protease gene, as major risk factor for wet form AMD (De Wan et al., Science 2006). Furthermore, we reported that the Japanese typical wet form AMD patients showed significant association with ARMS2/HTRA1 (Goto, Akahori et al., JOBDI 2009). The purpose of this study is to elucidate the function of ARMS2/HTRA1 gene promoter in wet-form AMD patients. The promoter sequence experiment showed that a great number of AMD patients had specific indel mutation in 3.8 kb upstream of HTRA1 gene. 2-3-fold increase of promoter activity was observed in indel HTRA1 promoter compared to control sequence (Iejima et al., JBC 2015). Furthermore, we created transgenic mice ubiquitously overexpressing mouse HtrA1 using the chicken act in promoter, continuous induction of HtrA1 in vivo was shown to lead to CNV, similar to wet AMD patients (Nakayama, Iejima et al., IOVS 2014). These results suggest that human HTRA1 expression is enhanced by AMD specific indel mutation in the promoter region of HTRA1 gene, and this enhanced HTRA1 may be concerned with induce retinal neovasucularization.

One of the major causes of reduced vision over the age of 50 is age-related macular degeneration (AMD). Although such a common pathology, there are no current guidelines for the first-line treatment of dry AMD. The aim of this study is to evaluate the therapeutic effects of high omega-3 fatty acids as anti-inflammatory agents in two sub-groups of dry AMD patients with 1) mild to moderate visual impairment and 2) with severe visual impairment (blindness). The key feature of this investigation is the frequent monitoring of the levels of specific fatty acids in patient's blood in order to adjust the treatment dose within the ideal therapeutic window. Following the positive outcome from our initial observational studies in patients with dry AMD, who demonstrated significant improvement in visual acuity (gain of ≥ 1 line of vision in 4.5 months) when taking a total of 5 g/day eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), additional studies were encouraged. The latest data which is presented in this chapter suggests that the eyes which had the greatest gain in vision (≥ 15 letters gain at 6 months) were from patients with mild to moderate visual impairment, who were taking between 5-7.5 g/day EPA and DHA and had a ratio of arachidonic acid (AA)/EPA < 2. In addition, a sub-group of dry AMD patients with severe visual impairment (< 6/60), showed significant increase in their visual acuity only 3 months following treatment with omega-3 fatty acids. The preliminary results indicate a promising therapeutic regime for dry AMD and perhaps for other types of retinopathies as well. Although initial results are encouraging, further investigations are necessary to establish a better understanding of the mode of action of these supplements and to observe their long-term effects.

Introduction: Methanol ingestion leads to severe damage to visual pathways and permanent loss of vision. Current treatment is aimed at removal of methanol from system and prevention of generation of toxic metabolites along with symptomatic management of patient. Autologous bone marrow mononuclear stem cells (MNC) can be used to rejuvenate the damaged retinal cells and restoration of vision.

Methods: Five patients suffering from methanol induced complete blindness within three months of insult and no known comorbidities during the past 6 months were enrolled to receive autologous bone marrow derived mononuclear cell fraction on compassionate grounds. The visual acuity and visual evoked responses (VER) were done at the time of enrollment and during follow-up visits.

Observations and results: Visual acuity of these patients at the time of enrollment: no perception of light. Improvement in visual acuity was recorded by 7 days which reached maximum at 3 weeks after treatment in three patients and three months in two patients. The patients had acuity of 6/9, finger counting and reading with magnifying glasses with no subsequent improvement till 2 years of follow-up. Visual Evoked Responses demonstrated improvements following treatment. No adverse reactions were noticed during follow-up.

Conclusion: Treatment with Autologous Bone marrow derived MNC offers a new line of management in patients with loss of vision following methanol ingestion. The efficacy and safety of this line of management needs to be evaluated in controlled clinical trials.

Knowledge gained from the field of tissue engineering, helped to develop a biological substitute that promotes tissue regeneration. The usual biological substitute consists of stem cells, growth factors and an appropriate scaffold. The present randomized controlled clinical and radiographic study was undertaken to evaluate the effectiveness of mesenchymal stem cells cultured on beta tricalcium phosphate (β-TCP) in combination with rh-PDGF-BB in treatment of infrabony defect in humans. A total of 24 infrabony defects in 14 systemically healthy patients were selected for the present study. The selected defects exhibited a probing pocket depth (PPD) of ≥ 5 mm and depth of infrabony component ≥ 3 mm as assessed by clinical and radiographic measurements and later confirmed by intrasurgical measurement. Baseline measurements included were Plaque Index (PI), Papillary Bleeding Index (PBI), Probing Pocket Depth (PPD), Relative gingival marginal level (RGML), Relative Clinical Attachment Level (R-CAL) and Radiographic Defect Depth (DD) and linear bone growth (LBG). 6 weeks after initial therapy, the defects were randomly assigned to either test group or control group. The control group was treated by an open flap debridement (OFD) only, while the test group was treated by a Stem cells cultured on β-TCP in combination with rh-PDGF-BB. All the measurements recorded preoperatively were repeated at 6 months after the surgery. The efficacy of each treatment modality was investigated through statistical analysis. Mean probing pocket depth reduction was significantly greater in test group (4.50 ± 1.08 mm) compared to the OFD group (3.50 ± 0.90 mm). Mean gains in clinical attachment level was 3.91 ± 1.37 mm in the test group and 2.08 ± 0.90 mm in the control group. The mean increase in gingival recession (GR) was less in test group (0.58 ± 0.79 mm) compared to OFD group (1.4 ± 0.66 mm). Radiographic defect depth reduction was greater in the test group (3.50 ± 0.67 mm) with 88.33% defect fill compared to control group (1.83 ± 0.38 mm) with only 52.77% defect fill. Linear bone growth (LBG) was significantly improved by 3.58 mm in test group, while in control group, it was 1.83 mm. Regenerative approach using Stem cells cultured on β-TCP in combination with rh-PDGF-BB for the treatment of human infrabony defects resulted in a significant added benefit in terms of CAL gains, PPD reductions greater radiographic defect fill and improvement in Linear bone growth (LBG) compared to the OFD alone.

Mesenchymal stem cells (MSCs) are of therapeutic interest to clinicians and researchers, as they have been shown to augment the osteogenic properties of bone grafts. MSCs are known to be prevalent in bone marrow, but are still limited in numbers. Hence, additional sources of MSCs are beneficial to increasing grafting potential. Aspirate material collected using the Reamer/Irrigator/Aspirator (RIA) device (Synthes; Paoli, PA) during reaming of the femoral shaft consists of three main components: bone fragments, liquid flow-through, and a fat layer. Currently, only the bone and liquid layers have been examined for osteoinductive elements, and the bone fragments are exclusively used as autologous bone graft. In the present study, a method to promote cellular outgrowth, tapping proliferative capacity from the previously discarded fatty layer of RIA aspirate, is described. Proliferating cells were successfully isolated from the bone and fatty layers of a consenting patient and found to be viable after liquid nitrogen storage. The osteogenic differentiation potential of the cells isolated from the fat and bone layers was assessed. Cells from both layers of the aspirate expressed statistically significant levels (p < 0.05) of the bone cell marker alkaline phosphatase compared to the control cells, suggesting differentiation along the osteoblastic pathway. Results from this pilot study indicate that the traditionally discarded fatty element of RIA aspirate may be a source of MSCs with bone-forming capabilities and the described isolation technique is effective. Combining the aspirate fatty and bony elements may enhance the clinical success of the RIA autograft.

Age related macular degeneration (AMD) is the leading cause of blindness in individuals older than 65 years of age. It is a multifactorial disorder and identification of risk factors enables individuals to make life style choices that may reduce the risk of disease. This review discusses the role of genetics, sunlight, diet, cardiovascular factors, smoking, and alcohol as possible risk factors for AMD. Genetics plays a more significant role in AMD than previously thought, especially in younger patients, histocompatibility locus antigen (HLA) and complement system genes being the most significant. Whether the risk of AMD is increased by exposure to sunlight, cardiovascular risk factors, and diet is more controversial. Smoking is the risk factor most consistently associated with AMD. Current smokers are exposed to a two to three times higher risk of AMD than non-smokers and the risk increases with intensity of smoking. Moderate alcohol consumption is unlikely to increase the risk of AMD. Optometrists as front-line informers and educators of ocular health play a significant role in increasing public awareness of the risks of AMD. Cessation of smoking, the use of eye protection in high light conditions, dietary changes, and regular use of dietary supplements should all be considered to reduce the lifetime risk of AMD.

The mobile phones (MP) are low power radio devices which work on electromagnetic fields (EMFs), in the frequency range of 900-1800 MHz. Exposure to MPEMFs may affect brain physiology and lead to various health hazards including brain tumors. Earlier studies with positron emission tomography (PET) have found alterations in cerebral blood flow (CBF) after acute exposure to MPEMFs. It is widely accepted that DNA double-strand breaks (DSBs) and their misrepair in stem cells are critical events in the multistage origination of various leukemia and tumors, including brain tumors such as gliomas. Both significant misbalance in DSB repair and severe stress response have been triggered by MPEMFs and EMFs from cell towers. It has been shown that stem cells are most sensitive to microwave exposure and react to more frequencies than do differentiated cells. This may be important for cancer risk assessment and indicates that stem cells are the most relevant cellular model for validating safe mobile communication signals. Recently developed technology for recording the human bio-electromagnetic (BEM) field using Electron photonic Imaging (EPI) or Gas Discharge Visualisation (GDV) technique provides useful information about the human BEM. Studies have recorded acute effects of Mobile Phone Electromagnetic Fields (MPEMFs) using EPI and found quantifiable effects on human BEM field. Present manuscript reviews evidences of altered brain physiology and stem cell functioning due to mobile phone/cell tower radiations, its association with increased cancer risk and explores early diagnostic value of EPI imaging in detecting EMF induced changes on human BEM.