Journal of Stem Cells最新文献

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.

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.

Objective: Key modalities of integrative medicine known to rejuvenate the mind and body are meditation, yoga, and controlled diet. It has been shown previously that intensive or prolonged mind and body therapies (MBT) may have beneficial effects on the well-being of healthy people and in patients. Telomerase activity and levels of peripheral blood adult pluripotent stem cells (PB-APSC) are reliable markers of long-term well-being that are known to decrease with age. The objective of this study is to understand the effect of our MBT program on telomerase activity and stem cells in blood collected from the participants.

Design: Here, we have investigated the effects of an intensive three weeks MBT retreat on telomerase activity and the peripheral blood stem cells in participants before and after the MBT. A total of 108 people were enrolled in the study; 38 men and 70 women (aged 18-90) randomly assigned for the study.

Results: Telomerase activity was greater in retreat participants at the end of the MBT retreat. About 45% of people showed more than one-fold increase of telomerase activity after our MBT program. Furthermore, about 27% of people showed more pronounced fold increase (2-fold) in telomerase activity after the MBT. In addition, a substantial percentage of people (about 90%) exhibited increased stem cell counts after the MBT.

Conclusions: The data suggest increased telomerase activity and stem cells count in peripheral blood from MBT retreat participants that may lead to increased longevity and better quality of life at latter age.

Nanotechnology techniques have a prominent role in the current technical and scientific scene. The layer-by-layer (LbL) deposition allows obtaining nanostructures with sophisticated multilayer, using a simple, but versatile technique. This procedure, which is used to coat and functionalize surfaces with nanometer- thick films, has applications in bioengineering, medicine, chemistry, materials and chemical engineering among other areas. Chitosan is a biomaterial, coming from the chitin, a very abundant polymer in nature, which has been recently tested as scaffolds. In this experiment we test the hypothesis that the hyaluronic acid-chitosan polyelectrolyte multilayer biofilm would be a good substrate to the adherence of equine mesenchymal stem cells derived from bone marrow. The results showed that these biofilms accelerate the process of cell adhesion on smooth surfaces, allowing a constant cell growth and creating a great option to cover surgical materials.

Objective: Duchenne muscular dystrophy (DMD) is a musculo-degenerative disease characterized by lack of dystrophin production with no definite cure available currently. Discarded umbilical cord is a potential source of mesenchymal stem cells which are non-immunogenic and can be used for transplantation in allogenic set ups. Given the regenerative and anti-inflammatory properties of mesenchymal stem cells (MSCs), here we investigated its role in the cellular therapy of DMD patients.

Design: This is a single-blinded study conducted in various hospitals of India situated in Mumbai, Delhi, and Lucknow. Inclusion criteria for enrolling the patients in the study were boys aged between 5 to 18 years, absence of dystrophin in the immunohistochemistry of muscle biopsy and mutation in dystrophin gene in cytogenetic analysis. The exclusion criteria were presence of dystrophin in the muscle biopsy, patients on corticosteroids etc. UC-MSCs (2 millions/kg body weight) were administered through IV and IM injection. Muscle power in muscles of proximal upper limb, distal upper limb, proximal lower limb, distal lower limb, hip flexors, hip extensors, hip abductors, and paraspinal muscles were measured in 11 DMD patients after UC-MSCs transplantation and were followed for up to 3 years (average follow up 1.5 years). 5 DMD patients did not receive any UC-MSCs transplantation and served as the control group.

Results: The treatment group (N = 11 at baseline) had a pretransplantation strength of 3.45 ± 1.0357 and 4.090 ± 0.8312 in muscles of proximal upper limb and distal upper limb respectively. After 1 year (N = 9) these strengths remained stable with an average of 3.78 (1.03) and 4.22 (0.83). In contrast, the control group (N = 5) has a pre-transplantation strength of 3.6 (0.54) and 4 (1) in the proximal and distal upper limb respectively. After 1 year, (N = 5) 3/5 subjects had a slight but not statistically significant decrease in the proximal upper limb, mean 3.0 (1.0) and 5/5 had a lunit decrease in strength, mean 3.0 (1.0). The treatment group had a pre-transplantation strength of 2.0909 ± 0.8312 and 3.1181 ± 0.8738 in muscles of distal and proximal lower limbs respectively. At 1 year (N = 9), 4/9 subjects had a 1 unit increase in strength in the distal lower limb (mean 3.78 (0.97)) and 8/9 subjects had a lunit increase in strength in the proximal lower limb, mean 3.11 (1.05). The control group has a mean of 3.41 (0.54) and 3.0 (1.0) at baseline in the distal and proximal lower limb respectively. By 1 year, 3/5 subjects had a 1 unit decrease (mean 2.8 (0.45)) and 5/5 had a lunit decrease, mean 2.0 (1.0) in distal and proximal lower limb strength. Stability in muscle function was also achieved in muscles of hip flexors, hip extensors, hip abductors, and paraspinal muscles at one year as compared to untreated group.

Conclusion: UC-MSCs administration not only resulted in the s

Glioblastomamultiforme (GBM) is the most common malignant and aggressive primary tumor of the brain in adults and characterized by a heterogeneous population of cells that are genetically unstable, highly infiltrative, angiogenic, and resistant to chemotherapy. Considerable efforts being devoted to identifying the molecular basis of resistance in GBM and exploring novel therapeutic targets that may improve overall survival. Several independent DNA repair mechanisms that normally safeguard genome integrity can facilitate drug resistance and cancer cell survival by removing chemotherapy- induced adducts. The recent data suggest that the most important mechanism of resistance to alkylating agents is the DNA repair enzyme O6-methylguanine methyltransferase (MGMT). Although, the treatment failure is a result of a number of causes, but currently, it has been demonstrated that a highly tumorigenic subpopulation of cancer cells called glioblastoma stem cells (GSCs) display relative resistance to radiation and chemotherapy. In fact, GBM stem cells express high levels of MGMT and this may account for GBM resistance following chemotherapy. GSCs also contribute to tumor growth through the stimulation of angiogenesis, which has been shown to be a useful therapeutic target in the treatment of recurrent or progressive malignant gliomas. In this review, we summarize the chemoresistance mechanisms of GBMs (to alkylating agents), with a special focus on the role of cancer stem cells.