scholarly journals Parhyale hawaiensis

2019 ◽  
Author(s):  
Otavio Jurgensen Diehl ◽  
Gisela de Aragao Umbuzeiro ◽  
Patrícia Kushima Assano
Keyword(s):  
Stem Cells ◽  
Marine Organisms ◽  
Toxicity Tests ◽  
Entire Life ◽  
Ecotoxicological Tests ◽  
Life Data ◽  
Environmental Concentrations ◽  
Parhyale Hawaiensis ◽  
Ability To Regenerate ◽  
Marine Amphipod

Parhyale hawaiensis is a marine amphipod of circumtropical distribution and has been used in acute ecotoxicological tests. However, sub lethal responses are important endpoints in ecotoxicology because they allow the assessment of effects at environmental concentrations. P. hawaiensis has the ability to regenerate its appendages, limbs and tissues after an injury or loss during their entire life. Data on effects of toxicants on appendages regeneration of marine organisms are still scarce. Regeneration can be used as an ecotoxicological endpoint to assess potential teratogenic compounds and their impact on stem cells. Thus, the aim of this study was to obtain data on regeneration of antennae of P. hawaiensis to determine the viability this endpoint on toxicity tests.

scholarly journals Viability of the marine amphipod Parhyale hawaiensis growth rate as an endpoint for chronic ecotoxicological tests

2019 ◽  
Author(s):  
Patricia Kushima Assano ◽  
Gisela de Aragao Umbuzeiro ◽  
Otávio Jürgensen Diehl ◽  
Rhaul de Oliveira
Keyword(s):  
Growth Rate ◽  
Chronic Toxicity ◽  
Sediment Quality ◽  
Marine Species ◽  
Toxicity Assessment ◽  
Model Organisms ◽  
Toxicity Tests ◽  
Ecotoxicological Tests ◽  
Parhyale Hawaiensis ◽  
Marine Amphipod

There is a lack of suitable marine species for ecotoxicological tests. Parhyale hawaiensis is a marine amphipod with circumtropical distribution. Recently, acute ecotoxicological procedures were standardized for these model organisms. However, its potential for chronic toxicity assessment still unclear. Sediment quality assessments using sublethal responses of benthic organisms, such as growth and reproduction, have been used to successfully evaluate moderately contaminated areas. The aim of this work was to evaluate the viability of growth rate as an sublethal endpoint for chronic toxicity tests.

scholarly journals Toxicity of sediments under the influence of the submarine emissary of Santos using the marine amphipod Parhyale hawaiensis.

2019 ◽  
Author(s):  
Gabriel Rampazzo Magalhães ◽  
Gisela de Aragao Umbuzeiro ◽  
Francine Inforçato Vacchi ◽  
Amanda dos Santos ◽  
Josiane Aparecida de Souza Vendemiatti ◽  
...  
Keyword(s):  
Organic Contaminants ◽  
Salt Water ◽  
Toxicity Tests ◽  
Aquatic Biota ◽  
Aqueous Fraction ◽  
Organic Extracts ◽  
Parhyale Hawaiensis ◽  
Marine Amphipod ◽  
Acute Toxicity Tests ◽  
Negative Impacts

In Brazil, the submarine emissary of Santos is considered one of the main emissaries of the country. However, the practice of effluent disposal in the oceans may have negative impacts on aquatic biota. When treatment is not appropriate several contaminants can reach the water and sediments of the disposal area. This work aimed to perform acute toxicity tests with marine amphipod Parhyale hawaiensis, which is a new model for toxicity tests, with sediment samples under the influence of the submarine emissary of Santos. Samples were collected at four different sites in four sampling campaigns and were evaluated as fresh sediment, dry sediment, aqueous fraction (elutriate with sediment and water), and organic extracts. Liquid samples were tested using 96-wells microplates, and the sediment using 12 wells-microplates containing sediment and salt water in 1:4 (w/v). Neonates (< 7 days old) P. hawaiensis were used and placed individually in each well. Exposure conditions were 96h, 24+2ºC, 12h/12h light and dark. From samples analyzed, fresh sediment presented a toxicity for 72% of samples, while dried sediment were toxic for 78% of samples. Besides, all aqueous fraction were negative and organic extracts were toxic for 71% samples. Results suggest that toxicity is mainly related to organic contaminants, which is possible to note that mortality and organic matter are directly proportionals. Therefore, we conclude that the sediments are being adversely affected by outfall discharge.

scholarly journals The effect of Malaysian stingless bee, Trigona spp. honey in promoting proliferation of the undifferentiated stem cell

2019 ◽  
pp. 10-19 ◽  
Author(s):  
Mohd Amin Marwan Mohamad ◽  
Muhammad Alif Mazlan ◽  
Muhammad Ibrahim ◽  
Afzan Mat Yusof ◽  
Shamsul Azlin Ahmad Shamsuddin ◽  
...  
Keyword(s):  
Stem Cells ◽  
Culture Media ◽  
Proliferative Effect ◽  
Natural Medicine ◽  
Ability To Regenerate ◽  
Potential Applications ◽  
Standard Culture ◽  
The Stability ◽  
Dose Dependent ◽  
Standard Culture Medium

Stem cells provide various potential applications in regenerative medicine through its ability of self-renewal and differentiation. Among the various stem cells, dental pulp stem cells (DPSCs) have shown encouraging results in their ability to regenerate. Honey has been used in traditional culture as a natural medicine in supporting wound healing. Yet, very few studies on honey were conducted for its potential as a proliferative agent for stem cells. The aim of this study is to evaluate the stability of two Trigona spp. honeys (1 and 2) added in culture media and its proliferative effect on DPSCs. Both honeys were diluted with standard culture medium through dilution process to prepare the concentrations of 0.01%, 0.04%, 0.10% and 0.25%. DPSCs were treated with the diluted honeys for 24 hours. The proliferative activity was determined through the images taken using an inverted microscope for every six hours. In addition, the MTT assay was conducted to determine the cell viability of DPSCs when treated with both honey 1 and 2 at various concentrations. The results showed a stable culture media added with honey for three days and a dose-dependent proliferative effect of both Trigona spp. honey samples on DPSCs. Optimum proliferative effects were observed at 24 hours for both Trigona spp. honey 1 and 2 on DPSCs. The optimum concentration of Trigona spp. honey 1 was from 0.04% to 0.10% and Trigona spp. honey 2 was below 0.01%. It is concluded that Trigona spp. honey has a promising proliferative effect on DPSCs.

Effect of cadmium on the embryos and juveniles of a tropical freshwater snail, Physa acuta (Draparnaud, 1805)

1998 ◽  
Vol 38 (7) ◽  
pp. 263-270 ◽  
Author(s):  
C. C. C. Cheung ◽  
P. K. S. Lam
Keyword(s):  
Early Life ◽  
Freshwater Snail ◽  
Toxicity Tests ◽  
Life Stages ◽  
Early Life Stages ◽  
Physa Acuta ◽  
Ecotoxicological Tests ◽  
Embryonic Growth ◽  
Potential Use ◽  
Tropical Freshwater

The effects of cadmium on early life stages of a freshwater snail, Physa acuta (Draparnaud), were investigated. The 24- and 48-hour LC50 for embryos were 1.27 mg/l (95% confidence interval: 1.13 - 1.42) and 0.85 mg/l (0.71 - 1.01), respectively. The 24- and 48-hour LC50 for juveniles were 1.32 mg/l (1.13 - 1.54) and 1.05 mg/l (0.81 - 1.36), respectively. An increase in cadmium concentrations at sublethal levels resulted in a significant reduction in embryo growth rate and embryo hatchability. Developmental deformities of the embryos were also observed. The NOEC and LOEC for embryonic growth were 0.32 and 0.50 mg/l, respectively, and the LOEC for hatchability was 0.13 mg/l. These results suggest that embryonic growth and hatchability are useful endpoints in chronic toxicity tests. In addition, the potential use of early life stages of pulmonate snails in ecotoxicological tests is discussed.

Isolation of Human Oral Keratinocyte Progenitor/Stem Cells

2007 ◽  
Vol 86 (4) ◽  
pp. 341-346 ◽  
Author(s):  
K. Izumi ◽  
T. Tobita ◽  
S.E. Feinberg
Keyword(s):  
Stem Cells ◽  
Cell Population ◽  
Proliferative Potential ◽  
Peroxisome Proliferator ◽  
Oral Keratinocytes ◽  
Peroxisome Proliferator Activated Receptor ◽  
Ability To Regenerate ◽  
Forming Efficiency ◽  
Stem Cell Populations

Progenitor/stem cell populations of epithelium are known to reside in the small-sized cell population. Our objective was to physically isolate and characterize an oral keratinocyte-enriched population of small-sized progenitor/stem cells. Primary human oral mucosal keratinocytes cultured in a chemically defined serum-free culture system, devoid of animal-derived feeder cells, were sorted by relative cell size and characterized by immunolabeling for β1 integrin, nuclear transcription factor, peroxisome proliferator-activated receptor-gamma, and cell-cycle analysis. Sorted cells were distinguished as progenitor/stem cells by functional assays and their ability to regenerate an oral mucosal graft. Small-sized cells demonstrated the lowest expression of peroxisome proliferator-activated receptor-gamma, the highest colony-forming efficiency, a longer long-term proliferative potential, an enriched quiescent cell population, and the ability to regenerate an oral mucosal graft, implying that the small-sized cultured oral keratinocytes contained an enriched population of progenitor/stem cells.

scholarly journals Optimisation of culture conditions for differentiation of C17.2 neural stem cells to be used for in vitro toxicity tests

2013 ◽  
Vol 27 (5) ◽  
pp. 1565-1569 ◽  
Author(s):  
Jessica Lundqvist ◽  
Johanna EL Andaloussi-Lilja ◽  
Christina Svensson ◽  
Helena Gustafsson Dorfh ◽  
Anna Forsby
Keyword(s):  
Stem Cells ◽  
Neural Stem Cells ◽  
Culture Conditions ◽  
Toxicity Tests ◽  
In Vitro Toxicity

scholarly journals Cartilage Regeneration in Human with Adipose Tissue-Derived Stem Cells: Current Status in Clinical Implications

2016 ◽  
Vol 2016 ◽  
pp. 1-12 ◽  
Author(s):  
Jaewoo Pak ◽  
Jung Hun Lee ◽  
Wiwi Andralia Kartolo ◽  
Sang Hee Lee
Keyword(s):  
Stem Cells ◽  
Adipose Tissue ◽  
Platelet Rich Plasma ◽  
Stromal Vascular Fraction ◽  
Cartilage Regeneration ◽  
Clinical Effectiveness ◽  
The Elderly ◽  
Current Status ◽  
Ability To Regenerate ◽  
Underlying Causes

Osteoarthritis (OA) is one of the most common debilitating disorders among the elderly population. At present, there is no definite cure for the underlying causes of OA. However, adipose tissue-derived stem cells (ADSCs) in the form of stromal vascular fraction (SVF) may offer an alternative at this time. ADSCs are one type of mesenchymal stem cells that have been utilized and have demonstrated an ability to regenerate cartilage. ADSCs have been shown to regenerate cartilage in a variety of animal models also. Non-culture-expanded ADSCs, in the form of SVF along with platelet rich plasma (PRP), have recently been used in humans to treat OA and other cartilage abnormalities. These ADSCs have demonstrated effectiveness without any serious side effects. However, due to regulatory issues, only ADSCs in the form of SVF are currently allowed for clinical uses in humans. Culture-expanded ADSCs, although more convenient, require clinical trials for a regulatory approval prior to uses in clinical settings. Here we present a systematic review of currently available clinical studies involving ADSCs in the form of SVF and in the culture-expanded form, with or without PRP, highlighting the clinical effectiveness and safety in treating OA.

scholarly journals Use of stem cells in tissue engineering and reconstruction of the maxillofacial region

2020 ◽  
Vol 8 (7) ◽  
pp. 2740
Author(s):  
Pankaj Kukreja ◽  
Modi Fahd Al Qahtani ◽  
Majedah Fahd Al Qahtani ◽  
Ahad Fahd Al Qahtani ◽  
Bhavna Jha Kukreja
Keyword(s):  
Stem Cells ◽  
Immune Responses ◽  
Functional Performance ◽  
Maxillofacial Surgery ◽  
Surgical Techniques ◽  
Flap Transfer ◽  
Daunting Task ◽  
Ability To Regenerate ◽  
Normal Functional ◽  
Craniofacial Defect

The oral and craniofacial defect reconstruction has been a daunting task for several decades. Many clinicians have attempted to switch surgical techniques in flap transfer to enhance the purposeful outcomes. In many cases, however, near total restoration of the native anatomy is not achievable. Also, the normal functional performance is not attainable, regardless of the surgical technique used. This problem is more evident within the oral and craniofacial region considering the importance of functions, such as speech, chewing, and appearance. Stem cells have attracted a growing interest within the scientific community chiefly for their ability to regenerate broken tissues and conjointly for their known potential in modulating inflammatory and immune responses. These skills have caused stem cells to be thought about as a promising strategic tool for a range of clinical maxillofacial applications. In this review, authors briefly summarize the applications of stem cells in maxillofacial surgery. 

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