20,552 research outputs found

    Non‐Invasive Assessment of the Embryo Viability via the Analysis of the Culture Media

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    Infertility in recent years is a growing public health issue throughout the developed world. Assisted reproductive techniques, especially in vitro fertilization, have the potential to partially overcome the low natural reproductive ratio. Nowadays, single embryo transfer gains grounds in clinical practice, urging the development of more reliable methods for selecting the best embryo. In the traditional clinical practice, embryos are selected for transfer based on morphological evaluation. In vitro culturing of embryos also provides a very important material for further non‐invasive evaluation by means of examining a biomarker in the spent culture medium (SEC). Current measure methods concentrate on the metabolomic activity of the developing embryos none compounds. These studies are mainly utilizing the tools of modern analytics and proteomics. In a paper published by Montskó et al. in 2015, the alpha‐1 chain of the human haptoglobin molecule was described as a quantitative biomarker of embryo viability. In a series of retrospective, blind experiments achieved more than 50% success rate. This chapter summarizes the currently available metabolomic and proteomic approaches as the non‐invasive molecular assessment of embryo viability

    A novel method for transmission electron microscopy study of cytoplasmic fragments from preimplantation human embryos

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    Transmission electron microscopy (TEM) is the main tool for exploring the intracellular damage and organelle distribution. The cause of producing embryo cytoplsamic fragmentation is not completely understood. Since the fragments have detrimental effects on embryo development, the ultrastructural analysis of fragments may play an important role in fragmentation etiology and in embryo development as well. There are no studies regarding the ultrastructure of fragments in transferable embryos, because the preparation for TEM is not vital and embryos are discarded inevitably. This study aims to introduce a new method for ultrastructural evaluation of fragments without damaging the human cleaving embryos

    Ultrastructure of cytoplasmic fragments in human cleavage stage embryos

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    Purpose: The goal of this study was to evaluate the ultrastructure of cytoplasmic fragments along with the effect of cytoplasmic fragment and perivitelline space coarse granulation removal (cosmetic microsurgery) from embryos before embryo transfer on ART outcomes. Methods: One hundred and fifty intracytoplasmic sperm injection cycles with male factor infertility were included in this prospective study. Patients were divided into three groups of case (n = 50), sham (n = 50), and control (n = 50). Embryos with 10–50 % fragmentation were included in this study. Cosmetic microsurgery and zona assisted hatching were only performed in case and sham groups respectively. Extracted fragments were evaluated ultrastructurally by transmission electron microscopy (TEM). Rates of clinical pregnancy, live birth, miscarriage, multiple pregnancies, and congenital anomaly in the three groups were also compared. Results: Micrographs from TEM showed that mitochondria were the most abundant structures found in the fragments along with mitochondria-vesicle complexes, Golgi apparatus, primary lysosomes, and vacuoles. There were no significant differences in demographic characteristics, laboratory and clinical data, or embryo morphological features between the groups. The rate of clinical pregnancy in control, sham, and case groups had no significant differences (24, 18, and 18 %, respectively). The rates of live birth, miscarriage, multiple pregnancy, and congenital anomaly were also similar between the different groups. Conclusions: Our data demonstrated that cosmetic microsurgery on preimplantation embryos had no beneficial effect on ART outcomes in unselected groups of patients. As mitochondria are the most abundant organelles found in cytoplasmic fragments, fragment removal should be performed with more caution in embryos with moderate fragmentation

    Development and germination of Sandersonia aurantiaca (Hook.) seeds : a thesis presented in partial fulfilment of the requirements for the degree of Master of Science in Plant Biology and Biotechnology at Massey University

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    Sandersonia aurantiaca (Hook.) has recently become an important horticultural crop through its economic value for export of its cut flowers and tubers. Little information however is available on seed structure, morphology, development and propagation. The main objectives of this study were to investigate the pattern of seed development, to find satisfactory methods of improving the seed germination and to assess possible mechanisms of seed dormancy of Sandersonia aurantiaca (Hook.). Seed development was investigated by fixing plant material in FAA solution, embedding in paraffin, and staining with safranin-fast green. A series of sections were examined and photographed under a microscope. Both embryo and endosperm development in Sandersonia show close similarity to development in Allium fistulosum (Alliaceae). Embryo development passes through early globular, late globular, elongated spheroidal and linear embryo development stages. Endosperm development conforms to the Nuclear type. Freely-growing walls between the endosperm nuclei may be associated with the embryo sac wall as projections. The structure of the mature seeds is very similar to that of Iris (Iridaceae) seeds. The small, linear embryo is embedded in the endosperm which constitutes most of the seed volume. Such small, linear embryos may be one reason for embryo dormancy in Sandersonia seed. A special structure (a conical or cylindrical protuberance) is observed in the inner part of the seed coat, which may combine with a lignified layer (and perhaps including the endosperm) to contribute to the coat-imposed domancy in this species. Eighty five treatments were firstly used to improve the germination percentage of Sandersonia seed. Only the treatment in which seeds scarified firstly with sandpaper for 1 min and then nicked near the radicle end showed increased germination from 0 to 10.6% by 30 days, at 20°C. Based on this result, 31 new treatment methods were designed in germination experiment 2. Water uptake patterns, allelopathic effect on lettuce seeds and embryo rescue of Sandersonia seed were also studied for assessing the possible mechanisms of dormancy. The findings of the present study suggest that the Sandersonia seeds have double dormancy. The dormancy mechanism is located in both the seed coat and the embryo and it consists of at least two steps that must be activated in sequence before germination can occur. The first step can be activated prematurely by scarifying and nicking the seeds, thus allowing the seed coat to become permeable to water, oxygen or to reduced mechanical restriction. The second step can be activated directly GA3 which stimulates embryo growth. This germination-promoting technique has great potential for Sandersonia for improvement of the germination percentage of seeds from 0 to about 70%, but development on a commercial scale needs further studies

    Dibucaine in Ionic-Gradient Liposomes: Biophysical, Toxicological, and Activity Characterization

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    Administration of local anesthetics is one of the most effective pain control techniques for postoperative analgesia. However, anesthetic agents easily diffuse into the injection site, limiting the time of anesthesia. One approach to prolong analgesia is to entrap local anesthetic agents in nanostructured carriers (e.g., liposomes). Here, we report that using an ammonium sulphate gradient was the best strategy to improve the encapsulation (62.6%) of dibucaine (DBC) into liposomes. Light scattering and nanotracking analyses were used to characterize vesicle properties, such as, size, polydispersity, zeta potentials, and number. In vitro kinetic experiments revealed the sustained release of DBC (50% in 7 h) from the liposomes. In addition, in vitro (3T3 cells in culture) and in vivo (zebrafish) toxicity assays revealed that ionic-gradient liposomes were able to reduce DBC cyto/cardiotoxicity and morphological changes in zebrafish larvae. Moreover, the anesthesia time attained after infiltrative administration in mice was longer with encapsulated DBC (27 h) than that with free DBC (11 h), at 320 μM (0.012%), confirming it as a promising long-acting liposome formulation for parenteral drug administration of dibucaine.Fil: Couto, Verônica M.. Universidade Estadual de Campinas; BrasilFil: Prieto, Maria Jimena. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto Multidisciplinario de Biología Celular. Grupo Vinculado al IMBICE - Grupo de Biología Estructural y Biotecnología-Universidad Nacional de Quilmes - GBEyB | Provincia de Buenos Aires. Gobernación. Comisión de Investigaciones Científicas. Instituto Multidisciplinario de Biología Celular. Grupo Vinculado al IMBICE - Grupo de Biología Estructural y Biotecnología-Universidad Nacional de Quilmes - GBEyB | Universidad Nacional de la Plata. Instituto Multidisciplinario de Biología Celular. Grupo Vinculado al IMBICE - Grupo de Biología Estructural y Biotecnología-Universidad Nacional de Quilmes - GBEyB; ArgentinaFil: Igartúa, Daniela. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto Multidisciplinario de Biología Celular. Grupo Vinculado al IMBICE - Grupo de Biología Estructural y Biotecnología-Universidad Nacional de Quilmes - GBEyB | Provincia de Buenos Aires. Gobernación. Comisión de Investigaciones Científicas. Instituto Multidisciplinario de Biología Celular. Grupo Vinculado al IMBICE - Grupo de Biología Estructural y Biotecnología-Universidad Nacional de Quilmes - GBEyB | Universidad Nacional de la Plata. Instituto Multidisciplinario de Biología Celular. Grupo Vinculado al IMBICE - Grupo de Biología Estructural y Biotecnología-Universidad Nacional de Quilmes - GBEyB; ArgentinaFil: Feas, Daniela Agustina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto Multidisciplinario de Biología Celular. Grupo Vinculado al IMBICE - Grupo de Biología Estructural y Biotecnología-Universidad Nacional de Quilmes - GBEyB | Provincia de Buenos Aires. Gobernación. Comisión de Investigaciones Científicas. Instituto Multidisciplinario de Biología Celular. Grupo Vinculado al IMBICE - Grupo de Biología Estructural y Biotecnología-Universidad Nacional de Quilmes - GBEyB | Universidad Nacional de la Plata. Instituto Multidisciplinario de Biología Celular. Grupo Vinculado al IMBICE - Grupo de Biología Estructural y Biotecnología-Universidad Nacional de Quilmes - GBEyB; ArgentinaFil: Ribeiro, Lígia N.M.. Universidade Estadual de Campinas; BrasilFil: Silva, Camila M.G.. Universidade Estadual de Campinas; BrasilFil: Castro, Simone R.. Universidade Estadual de Campinas; BrasilFil: Guilherme, Viviane A.. Universidade Estadual de Campinas; BrasilFil: Dantzger, Darlene D.. Universidade Estadual de Campinas; BrasilFil: Machado, Daisy. Universidade Estadual de Campinas; BrasilFil: Alonso, Silvia del Valle. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto Multidisciplinario de Biología Celular. Grupo Vinculado al IMBICE - Grupo de Biología Estructural y Biotecnología-Universidad Nacional de Quilmes - GBEyB | Provincia de Buenos Aires. Gobernación. Comisión de Investigaciones Científicas. Instituto Multidisciplinario de Biología Celular. Grupo Vinculado al IMBICE - Grupo de Biología Estructural y Biotecnología-Universidad Nacional de Quilmes - GBEyB | Universidad Nacional de la Plata. Instituto Multidisciplinario de Biología Celular. Grupo Vinculado al IMBICE - Grupo de Biología Estructural y Biotecnología-Universidad Nacional de Quilmes - GBEyB; ArgentinaFil: de Paula, Eneida. Universidade Estadual de Campinas; Brasi

    Immuno Magnetic Thermosensitive Liposomes For Cancer Therapy

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    The present work describes the encapsulation of the drug doxorubicin (DOX) in immuno paramagnetic thermosensitive liposomes. DOX is the most common chemotherapeutic agent for the treatment of a variety of carcinomas. However, the pure drug has high cytotoxicity and therefore requires a targeted and biocompatible delivery system. The introduction includes concepts, modalities, and functionalities of the project. First, a detailed description of the cell type (triple-negative breast cancer) is given. Furthermore, the importance of liposomal doxorubicin is explained and the current state of research is shown. The importance of modification to achieve thermosensitive properties and the procedure for co-encapsulation with Gd chelate to achieve paramagnetic properties is also discussed. In addition, the first part describes the surface modification with ADAM8 antibodies, which leads to improved targeting. The second part of the thesis covers the different materials and methods used in this paper. The production of the liposomes LipTS, LipTS-GD, LipTS-GD-CY, LipTS-GD-CY-MAB and the loading of DOX using an ammonium sulfate gradient method were described in detail. The results part deals with the physicochemical characterization using dynamic light scattering and laser Doppler velocimetry, which confirmed a uniform monodisperse distribution of the liposomes. These properties facilitate the approach of liposomes to target cancer cells. The influence of lipid composition of liposomes, co-encapsulation with Gd chelate and surface modification of liposomes was evaluated and described accordingly. The size and structure of the individual liposomal formulations were determined by atomic force microscopy and transmission electron microscopy. Morphological examination of the liposomes confirmed agreement with the sizes obtained by dynamic light scattering. Temperature-dependent AFM images showed an intact liposome structure at 37 °C, whereas heating by UHF-MRI led to a lipid film indicating the destruction of the lipid bilayer. Furthermore, TEM images showed the morphological properties of the liposomes and gave a more precise indication of how Gd-chelate accumulates within the liposomes. Liposomes with Gd-chelate showed well-separated vesicles, suggesting that Gd- chelate is deposited in the lipid bilayer of the liposomes. Gd was encapsulated in the hydrophilic core whereas chelate was extended into the lipid bilayer. By differential scanning calorimetry and drug release, the heat-sensitive functionality of the liposomes could be determined. Liposomes showed a beginning of phase transition temperature at about 38 °C, which can be achieved by UHF-MRI exposure. The maximum phase transition temperature in the case of LipTS-GD and LipTS-GD-CY-MAB was 42 °C and 40 °C, respectively. A proof of concept study for the thermosensitive properties of liposomes and a time-dependent DOX release profile in hyperthermia was performed. Gd-chelate is encapsulated in both LipTS-GD and LipTS-GD-CY-MAB and led to paramagnetic properties of the liposomes. This facilitates imaging mediated DOX delivery and diagnosis of the solid tumor and metastatic cells. The change in relaxation rate R1 of liposomes was quantified before and after heating above Tm (T> Tm). The relaxivity of the liposomes was obtained from the adapted slope of the relaxation rate against the Gd concentration. Remarkably, the relaxation rate and relaxivity increased after heating the liposomes above Tm (T> Tm), suggesting that the liposomes opened, released Gd chelate, and the exchange of water molecules became faster and more practicable. Toxicity studies describe the different mechanisms for induced DOX toxicity. The increased cytotoxic effect at elevated temperatures showed that the induced toxicity is thermally dependent, i.e. DOX was released from the liposomes. The high viability of the cells at 37 °C indicates that the liposomes were intact at normal physiological temperatures. Under UHF-MRI treatment, cell toxicity due to elevated temperature was observed. The cellular uptake of liposomes under UHF-MRI was followed by a confocal laser scanning microscope. An increase in fluorescence intensity was observed after UHF-MRI exposure. The study of the uptake pathway showed that the majority of liposomes were mainly uptake by clathrin-mediated endocytosis. In addition, the liposomes were modified with anti-ADAM8 antibodies (MAB 1031) to allow targeted delivery. The cellular binding capabilities of surface-modified and non-modified liposomes were tested on cells that had ADAM8 overexpression and on ADAM8 knockdown cells. Surface-modified liposomes showed a significant increase in binding ability, indicating significant targeting against cells that overexpress ADAM8 on their surface. In addition, cells with knockdown ADAM8 could not bind a significant amount of modified liposomes. The biocompatibility of liposomes was assessed using a hemolysis test, which showed neglected hemolytic potential and an activated thromboplastin time (aPTT), where liposomes showed minimal interference with blood clotting. Hemocompatibility studies may help to understand the correlation between in vitro and in vivo. The chorioallantois model was used in ovo to evaluate systematic biocompatibility in an alternative animal model. In the toxicity test, liposomes were injected intravenously into the chicken embryo. The liposomes showed a neglectable harmful effect on embryo survival. While free DOX has a detrimental effect on the survival of chicken embryos, this confirms the safety profile of liposomes compared to free DOX. LipTS-GD-CY-MAB were injected into the vascular system of the chicken embryo on egg development day 11 and scanned under UHF-MRI to evaluate the magnetic properties of the liposomes in a biological system with T2-weighted images (3D). The liposomal formulation had distinct magnetic properties under UHF MRI and the chick survived the scan. In summary, immunomagnetic heat-sensitive liposomes are a novel drug for the treatment of TNBC. It is used both for the diagnosis and therapy of solid and metastasizing tumors without side effects on the neighboring tissue. Furthermore, a tumor in the CAM model will be established. Thereafter, the selective targeting of the liposomes will be visualized and quantitated using fluorescence and UHF-MRI. Liposomes are yet to be tested on mice as a xenograft triple-negative breast cancer model, in which further investigation on the effect of DOX-LipTS-GD-CY-MAB is evaluated. On one hand, the liposomes will be evaluated regarding their targetability and their selective binding. On the other hand, the triggered release of DOX from the liposomes after UHF-MRI exposure will be quantitated, as well as evaluate the DOX-Liposomes therapeutic effect on the tumor

    Fine morphological assessment of quality of human mature oocytes after slow freezing or vitrification with a closed device: a comparative analysis

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    BACKGROUND: Human mature oocytes are very susceptible to cryodamage. Several reports demonstrated that vitrification might preserve oocyte better than slow freezing. However, this is still controversial. Thus, larger clinical, biological and experimental trials to confirm this concept are necessary. The aim of the study was to evaluate and compare fine morphological features in human mature oocytes cryopreserved with either slow freezing or vitrification. METHODS: We used 47 supernumerary human mature (metaphase II) oocytes donated by consenting patients, aged 27-32 years, enrolled in an IVF program. Thirtyfive oocytes were cryopreserved using slow freezing with 1.5 M propanediol +0.2 M sucrose concentration (20 oocytes) or a closed vitrification system (CryoTip Irvine Scientific CA) (15 oocytes). Twelve fresh oocytes were used as controls. All samples were prepared for light and transmission electron microscopy evaluation. RESULTS: Control, slow frozen/thawed and vitrified/warmed oocytes (CO, SFO and VO, respectively) were rounded, 90-100 mum in diameter, with normal ooplasm showing uniform distribution of organelles. Mitochondria-smooth endoplasmic reticulum (M-SER) aggregates and small mitochondria-vesicle (MV) complexes were the most numerous structures found in all CO, SFO and VO cultured for 3-4 hours. M-SER aggregates decreased, and large MV complexes increased in those SFO and VO maintained in culture for a prolonged period of time (8-9 hours). A slight to moderate vacuolization was present in the cytoplasm of SFO. Only a slight vacuolization was present in VO, whereas vacuoles were almost completely absent in CO. Amount and density of cortical granules (CG) appeared abnormally reduced in SFO and VO, irrespective of the protocol applied. CONCLUSIONS: Even though, both slow freezing and vitrification ensured a good overall preservation of the oocyte, we found that: 1) prolonged culture activates an intracellular membrane "recycling" that causes the abnormal transformation of the membranes of the small MV complexes and of SER into larger rounded vesicles; 2) vacuolization appears as a recurrent form of cell damage during slow freezing and, at a lesser extent, during vitrification using a closed device; 3) premature CG exocytosis was present in both SFO and VO and may cause zona pellucida hardenin

    An in Vitro Evaluation of the Effect of Bovine Viral Diarrhea Virus on Preimplantation Bovine Embryos.

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    A total of 402 bovine embryos, non-surgically collected on day 6.5-7.5 after estrus, were utilized in evaluation of fluorescein diacetate (FDA) for estimating embryo viability in vitro and to investigate the effect of Bovine Viral Diarrhea (BVD) Virus on embryonic development during in vitro culture. Fluorescent assessment, using UV microscopy (440-480 nm) of embryos after staining in FDA (2.5 (mu)g/ml phosphate buffered saline: PBS), was found to be a rapid, non-toxic and accurate method for evaluation of viability. Embryos with highest fluorescent scores (Score = 4) prior to culture developed at the highest rate (95.7%), while embryos with no fluorescence (score = 0) did not develop. Significant correlations were found between morphological grading and fluorescent scores (r = .71), although FDA was more sensitive in estimating positive development. The investigation of the effect of BVD virus on development of bovine embryos was divided into three studies: (1) BVD virus cultured with live and dead embryos each with and without zona pellucida (four treatments), (2) Micro-injection of BVD virus directly into the blastocele of blastocysts and (3) transfer of BVD virus-exposed embryos into recipient cows. In the first study, live embryos (with and without a zona pellucida) assessed by FDA, developed at normal rates when exposed to BVD virus, showing that embryonic development was independent of the zona pellucida. Microinjection of BVD virus (Study 2) did not reduce in vitro development (91.7%) as compared with control medium-injected blastocysts (85.0%) or non-injected controls (88.3%). In vitro development was 75 and 71 percent for control and BVD virus-exposed embryos, respectively (Study 3). Pregnancy rates were 20.0 and 13.3 percent for control and BVD virus-exposed embryos at 65 days post-transfer. Embryonic mortality was higher in recipients transferred with BVD virus-exposed embryos (5 of 30, 16.7%) compared to controls (3 of 30, 10%); however, this difference was not statistically significant. (Abstract shortened with permission of author.)

    Toward in vitro fertilization in Brachiaria spp.

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    Brachiaria are forage grasses widely cultivated in tropical areas. In vitro pollination was applied to accessions of Brachiaria spp. by placing pollen of non-dehiscent anthers on a solid medium near isolated ovaries. Viability and in vitro germination were tested in order to establish good conditions for pollen development. Comparing sexual to apomictic plants, apomictic pollen has more abortion after meiosis during the microspore stage and a lower viability and, of both types, only some plants have sufficient germination in a high sugar concentration. Using in vitro pollination with the sexual plant, the pollen tube penetrates into the nucellus and micropyle, but the embryo sac degenerates and collapses. In the apomictic B. decumbens, in vitro pollination leads to the transfer of the sperm nuclei into the egg cell and the central cell. The results are discussed according to normal fertilization and barriers in sexual and apomictic plants
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