841 research outputs found
Human Peripheral Blood Derived Hematopoietic Stem Cell: History, the Isolation Methods and Investigation of Different Parameters Effects on Their Differentiation to the Body Cells
Blood and the system that forms it, known as the hematopoietic system, consist of many cell types with specialized functions. Red blood cells (erythrocytes) carry oxygen to the tissues. Platelets (derived from megakaryocytes) help prevent bleeding. Granulocytes (neutrophils, basophils and eosinophils) and macrophages (collectively known as myeloid cells) fight infections from bacteria, fungi, and other parasites such as nematodes (ubiquitous small worms). Some of these cells are also involved in tissue and bone remodeling and removal of dead cells. B-lymphocytes produce antibodies, while T-lymphocytes can directly kill or isolate by inflammation cells recognized as foreign to the body, including many virus-infected cells and cancer cells. Many blood cells are short-lived and need to be replenished continuously; the average human requires approximately one hundred billion new hematopoietic cells each day. The continued production of these cells depends directly on the presence of Hematopoietic Stem Cells (HSCs), the ultimate, and only, source of all these. Peripheral blood stem cells (PBSC) are rapidly becoming the primary rescue modality for autologous transplantation and are now actively being investigated in the allogeneic transplant setting. Many investigators and clinical researchers believe that PBSC are likely to replace bone marrow stem cells entirely, for use in clinical transplantation in the not too distant. Hematopoietic stem cells (HSCs) are the blood cells that give rise to all the other blood cells. They give rise to the myeloid (monocytes and macrophages, neutrophils, basophils, eosinophils, erythrocytes, megakaryocytes/platelets, dendritic cells), and lymphoid lineages (T-cells, B-cells, NK-cells). The definition of hematopoietic stem cells has changed in the last two decades. The hematopoietic tissue contains cells with long-term and short-term regeneration capacities and committed multipotent, oligopotent, and unipotent progenitors
Human Umbilical Cord Blood Stem Cells Differentiate into Keratinocytes under In Vitro Conditions and Culturing Differentiated Cells on Bacterial Cellulose Film
Mesenchymal stem cells (MSC) are capable of self renewing and differentiating into other cell types. Human umbilical cord blood (HUCB) has been investigated as an alternative source to bone marrow. The aim of our examinations was to investigate MSC of HUCB could differentiate into keratinocytes under in vitro conditions. In this study, we examined the differentiation with chemical compounds, then to identify the stem cells are differentiated or not, PCR by using the expression of gene cytokeratin 18 was performed and to examine the proliferation characteristic of differentiated keratinocyte from HUCBMSCs, cultured them on cellulose film. Analysis of PCR confirmed the expression of cytokeratin 18 in keratinocytes; results of our study show that cellulose film isn’t a compatible substrate for differentiated keratinocytes. And growth factor, BMP4, with hydrocortisone and ascorbic acid with specific amounts is an appropriate induction factor for inducing of differentiation into keratinocytes
Association between vitamin A and E and apolipoprotein A and B levels in type 2 diabetes
Objective. To determine the relationship between serum vitamin A and E and apolipoprotein levels in type 2 diabetic patients. Setting. Shariati Hospital, Tehran, Iran. Subjects and methods. One hundred and seventeen eligible type 2 diabetic patients who attended the Endocrine Research and Metabolism Center between 2002 and 2004 were enrolled in the study. Blood samples were collected after a 12 - 14-hour overnight fast for the measurement of serum levels of total cholesterol, triglyceride, high-density lipoprotein (HDL), low-density lipoprotein (LDL), apolipoprotein (apo) A1 and apoB, and vitamins A and E. Anthropometric indices were determined by physical examination. Data were analysed statistically using Pearson's coefficient, multiple regression, and partial and bivariate correlations. Results. The mean body mass index (BMI) of the subjects was 27.4 ± 3.7 kg/m2. The mean (± standard deviation (SD)) serum levels of vitamins A and E were 0.5 ± 0.1 μg/ml and 9.5 ± 2.6 μg/ml, respectively. There were no significant differences in the plasma levels of vitamins A and E in males and females. Mean serum levels of vitamins A and E were within the normal range for both sexes. Serum lipid levels (total cholesterol, triglyceride and apoB) correlated with serum levels of vitamin E (p < 0.05). Serum levels of vitamins A and E were also correlated (p < 0.05). Standardised vitamin E levels showed significant negative correlation with most studied lipid profiles (p < 0.05). Conclusion. This study found that mean serum levels of the natural antioxidants vitamin E, and especially vitamin A, were close to the lower end of the normal range of these antioxidants in type 2 diabetics. Also, serum vitamin E and standardised vitamin E levels were important predictors of serum apoA1 levels in these patients. South African Journal of Clinical Nutrition Vol. 19(1) 2006: 39-4
Prevalence rate of white spot syndrome virus (WSSV) in farmed white leg shrimp (Litopenaeus vannamei) in Bushehr province
We surveyed presence of white spot syndrome virus (WSSV) in farmed white leg shrimp in Bushehr province with assumed a prevalence of 2% of virus in target population. Hence, 468 samples were collected in two separate phases from May to October 2006. In the first phase, 200 samples (each sample was 150 pieces of post larvae with average age 7 days) were taken from 3 active hatcheries and in the second phase, 268 samples from 418 ponds in 5 sites were collected. Samples were tested by "Nested PCR" for detection of WSSV with 1Q2000 commercial kits. Results were negative and with respect to sampling method and sensitivity and specifity of Nested PCR we concluded that cultured shrimps were free of WSSV in 2006 in Bushehr province
Effect of selective heart rate slowing in heart failure with preserved ejection fraction
Background Heart failure with preserved ejection fraction (HFpEF) is associated with significant morbidity and mortality but is currently refractory to therapy. Despite limited evidence, heart rate reduction has been advocated, on the basis of physiological considerations, as a therapeutic strategy in HFpEF. We tested the hypothesis that heart rate reduction improves exercise capacity in HFpEF. Methods and Results We conducted a randomized, crossover study comparing selective heart rate reduction with the If blocker ivabradine at 7.5 mg twice daily versus placebo for 2 weeks each in 22 symptomatic patients with HFpEF who had objective evidence of exercise limitation (peak oxygen consumption at maximal exercise [GraphicO2 peak] <80% predicted for age and sex). The result was compared with 22 similarly treated matched asymptomatic hypertensive volunteers. The primary end point was the change in GraphicO2 peak. Secondary outcomes included tissue Doppler–derived E/e′ at echocardiography, plasma brain natriuretic peptide, and quality-of-life scores. Ivabradine significantly reduced peak heart rate compared with placebo in the HFpEF (107 versus 129 bpm; P<0.0001) and hypertensive (127 versus 145 bpm; P=0.003) cohorts. Ivabradine compared with placebo significantly worsened the change in GraphicO2 peak in the HFpEF cohort (-2.1 versus 0.9 mL·kg−1·min−1; P=0.003) and significantly reduced submaximal exercise capacity, as determined by the oxygen uptake efficiency slope. No significant effects on the secondary end points were discernable. Conclusion Our observations bring into question the value of heart rate reduction with ivabradine for improving symptoms in a HFpEF population characterized by exercise limitation
Advanced ultra-light multifunctional metallic-glass wave springs
We show that, using thermo -elastic processing, metallic -glass foils can be shaped, without being embrittled, into linear and annular wave springs. These springs exhibit an undulatory behaviour, unique to metallic -glass foils, in which under compression the number of arcs in the spring increases, increasing the load -bearing capacity and the spring constant. We evaluate the performance limits of the metallic -glass wave springs, and consider how the undulatory behaviour can be exploited. The metallic -glass springs can operate over the same load -ranges as commercially available crystalline wave springs, but have material volumes (and therefore weights) that are one to two orders of magnitude less. Their energy storage per unit material volume is as high as 2600 kJ m – 3 . We suggest that the undulatory behaviour is important in rendering the springs fail -safe in case of overload. We discuss the range of applicability of thermo -elastic processing, the likely working limit of metallic -glass wave springs, and the potential for application of metallic -glass springs in MEMS devices
Estimating the completeness of gastric cancer registration in Ardabil/Iran by a capture-recapture method using population-based cancer registry data
Background: Knowledge of cancer incidences is essential for cancer prevention and control programs. Capture-recapture methods have been recommended for reducing bias and increasing the accuracy of cancer incidence estimations. This study aimed to estimate the completeness of gastric cancer registration by the capture-recapture method based on Ardabil population-based cancer registry data. Materials and Methods: All new cases of gastric cancer reported by three sources, pathology reports, death certificates and medical records that reported to Ardabil population-based cancer registry in 2006 and 2008 were enrolled in the study. The duplicate cases based on the similarity of first name, surname and fathers names were identified between sources. The estimated number of gastric cancers was calculated by the log-linear method using Stata 12 software. Results: A total of 857 new cases of gastric cancer were reported from three sources. After removing duplicates, the reported incidence rates for the years 2006 and 2008 were 35.3 and 32.5 per 100,000 population, respectively. The estimated completeness calculated by log-linear method for these years was 36.7 and 36.0, respectively. Conclusions: These results indicate that none of the sources of pathology reports, death certificates and medical records individually or collectively fully cover the incident cases of gastric cancer. We can obtain more accurate estimates of incidence rates using the capture-recapture method
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The intersection of blockchain technology and circular economy in the agri-food sector
The following are the supplementary data related to this article: Table A1. Main drivers and examples of food loss and waste across food supply chains (not exhaustive). Available online at: https://ars.els-cdn.com/content/image/1-s2.0-S2352550922002986-mmc1.docx (Word document (33KB)); Table B1. A List of the reviewed literature and a summary of the findings (in total 44 articles were collected of which 39 were retrieved from databases and five articles were added manually after checking the references within the reviewed articles). Available online at: https://ars.els-cdn.com/content/image/1-s2.0-S2352550922002986-mmc2.docx (Word document (59KB)); Table C1. Evidence of employing blockchain-based use cases on the ‘Circular Economy’ within the agri-food domain. Available online at: https://ars.els-cdn.com/content/image/1-s2.0-S2352550922002986-mmc3.docx (Word document (47KB)).Copyright © 2022 The Authors / Institution of Chemical Engineers. A transition towards a circular economy within the agri-food sector requires the improvement of efficiency in resource utilization, the prevention of food loss or waste, whilst adopting regenerative agricultural practices. In addition to the technical challenges, the agri-food industry needs to address the food safety concerns resulting from biomass recycling processes. Increasingly, blockchain technology is gaining traction, moving towards more sustainable and precision agriculture. The blockchain is a decentralized, immutable, and shared database that records the provenance of digital assets, making it a suitable platform for traceability and food supply chain management. Despite its growing importance, the existing literature regarding these themes and the empirical evidence of blockchain-based solutions for a circular economy is rather fragmented. This paper offers a scoping review regarding the role of blockchain technology in the transition towards a circular food system. A total of 44 papers published in peer-reviewed journals were reviewed to identify new scientific insights into the application of blockchains within the agricultural sector. The results indicate that blockchain technology has a great potential in reducing food loss through optimized eco-efficiency (e.g., digitalization and integration with the Internet of Things) and by alleviating asymmetric information (by increasing transparency and reducing dependence on intermediaries). However, in the case of recycling efficiency, despite its potential, there remains a paucity of evidence regarding the use of blockchain technology in improving the residual valorization processes. Furthermore, there is a stream of literature focusing on the ability of blockchain-enabled traceability (e.g., for organic production or supply chain management). Yet, the role of blockchain traceability in the monitoring of risks from recycled biomass and the reporting of the sustainability performance in the supply chain has received scant attention within research literature. These results provide insights for supply chain management operations with the view of shifting towards a circular economy whilst also suggesting an agenda for future research areas.This work was supported by the Swedish University of Agricultural Sciences, Sweden, by a scholarship from L Nannesson’s foundation, grant number Dnr SLU.ua.2019.3.1.5-617
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