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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
141

New transcription factors in early eye development in mouse. / CUHK electronic theses & dissertations collection

January 2008 (has links)
In conclusion, the results suggested the important role of Ncl in driving the optic vesicle formation during early eye development. / The eye is a complex sense organ. It develops from different embryonic origins that including neural ectoderm, surface ectoderm, neural crest and paraxial mesoderm. Morphogenetic waves occur during eye development involve timely interactions of transcription factors and inductive signaling to ensure the correct temporal and spatial development of different components. Genetic studies of congenital eye defects, especially mutation screening and gene targeting, have provided the information about the molecular regulation in the complex processes of eye development. However, our knowledge of the basic genetic pathways that regulate the normal embryonic eye formation is incomplete. / Though the developing eye is believed to be highly specialized extension from the developing neural tube, the formation of major eye structure involves independent coordination of inductive interactions and regional specifications; formation of neural connections between retina and optic tectum; and maturation to a functional eye. There is not much information about eye-specific expression in early embryonic period. In this study, microarray was used to profile the molecular changes occurring in the developing mouse eye between the stage of optic vesicle evagination at E9.5 and completion of basic eye formation at P0. Differentially expressed transcription factor and signaling molecules, including nucleolin gene (Ncl), in the early developing eye were displayed. Temporal expression patterns were confirmed by quantitative real time PCR and spatial expressions patterns were confirmed by the whole-mount in situ hybridization. siRNA and overexpression vector targeting nucleolin transcript was designed to study their roles in the early eye morphogenesis during mouse embryogenesis in vitro. The loss of function phenotype after nucleolin knockdown was demonstrated by the absence of early optic vesicles with normal neural tube in the developing mouse embryos. Ectopic optic vesicle in developing mouse embryo was resulted under overexpression of Ncl . With the aim to study the biological roles of Ncl in mouse embryonic eye development in vivo, both conventional and conditional knockout techniques were attempted. The expression and functional studies revealed that a new neural tube independent signaling pathway regulated in the induction and formation of optic vesicles in the early eye formation. / Tang, Ling Yin. / Source: Dissertation Abstracts International, Volume: 70-06, Section: B, page: 3294. / Thesis (Ph.D.)--Chinese University of Hong Kong, 2008. / Includes bibliographical references (leaves 138-146). / Electronic reproduction. Hong Kong : Chinese University of Hong Kong, [2012] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Electronic reproduction. [Ann Arbor, MI] : ProQuest Information and Learning, [200-] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Abstracts in English and Chinese. / School code: 1307.
142

Mechanisms responsible for the alteration of lipolysis in diabetic (+db/+db) mice.

January 2008 (has links)
Lam Tsz Yan. / Thesis submitted in: October 2007. / Thesis (M.Phil.)--Chinese University of Hong Kong, 2008. / Includes bibliographical references. / Abstracts in English and Chinese. / Abstract (English) --- p.i / 論文摘要 --- p.iv / Acknowledgements --- p.vi / Publications --- p.vii / Abbreviations --- p.ix / Contents --- p.x / Chapter 1. --- General Introduction --- p.1 / Chapter 1.1. --- Obesity --- p.1 / Chapter 1.1.1. --- Overview --- p.1 / Chapter 1.1.2. --- Pathophysiology --- p.1 / Chapter 1.1.3. --- Central obesity --- p.3 / Chapter 1.2. --- Diabetes --- p.7 / Chapter 1.2.1. --- Overview --- p.7 / Chapter 1.2.2. --- Pathophysiology --- p.8 / Chapter 1.3. --- Lipolysis --- p.9 / Chapter 1.3.1. --- Proteins participating in triglyceride lipolysis --- p.10 / Chapter 1.3.1.1. --- Hormone-sensitive lipase (HSL) --- p.10 / Chapter 1.3.1.2. --- Adipose triglyceride lipase (ATGL) --- p.10 / Chapter 1.3.1.3. --- Perilipins --- p.11 / Chapter 1.3.2. --- Abnormal regulation of lipolysis in obesity --- p.11 / Chapter 1.3.3. --- Disturbed lipolysis in insulin resistance --- p.13 / Chapter 1.4. --- Pharmacotherapy --- p.13 / Chapter 1.4.1. --- Obesity --- p.13 / Chapter 1.4.1.1. --- Orlistat --- p.13 / Chapter 1.4.1.2. --- Sibutramine --- p.14 / Chapter 1.4.1.3. --- Others --- p.15 / Chapter 1.4.2. --- Diabetes --- p.15 / Chapter 1.4.2.1. --- Modulation of the β-cells functions --- p.15 / Chapter 1.4.2.2. --- Control of glucose output --- p.16 / Chapter 1.4.2.3. --- Modulation of carbohydrate absorption --- p.16 / Chapter 1.4.2.4. --- Thiazolidinediones (TZDs) --- p.16 / Chapter 1.5. --- Animal models used in type 2 diabetes and obesity research --- p.17 / Chapter 1.6. --- Aim of study --- p.18 / Chapter 2. --- β-Adrenoceptors (β-ARs) --- p.21 / Chapter 2.1. --- Introduction --- p.21 / Chapter 2.1.1. --- Hormonal control of lipolysis --- p.21 / Chapter 2.1.1.1. --- Catecholamines --- p.21 / Chapter 2.1.1.2. --- Insulin --- p.23 / Chapter 2.1.2. --- Folic acid (folate) --- p.23 / Chapter 2.1.2.1. --- Physiological roles of folate --- p.23 / Chapter 2.1.2.2. --- Folate deficiency and its consequences --- p.24 / Chapter 2.1.2.3. --- Hyperhomocysteinemia --- p.24 / Chapter 2.1.2.4. --- Pleiotropic effects of folate --- p.25 / Chapter 2.1.2.5. --- Role of folate in type 2 diabetes and obesity --- p.26 / Chapter 2.1.3. --- Lingzhi --- p.28 / Chapter 2.1.3.1. --- Triterpenoids --- p.29 / Chapter 2.1.3.2. --- Polysaccharides --- p.30 / Chapter 2.2. --- Materials and methods --- p.32 / Chapter 2.2.1. --- Materials --- p.32 / Chapter 2.2.1.1. --- Composition of physiological salt solution --- p.32 / Chapter 2.2.1.2. --- Materials used in lipolysis experiment --- p.32 / Chapter 2.2.1.3. --- Materials used in reverse transcription polymerase chain reaction (RT-PCR) --- p.34 / Chapter 2.2.1.4. --- Materials used in Western blotting --- p.34 / Chapter 2.2.2. --- Methods --- p.36 / Chapter 2.2.2.1. --- Lipolysis experiment --- p.36 / Chapter 2.2.2.1.1. --- Animals --- p.36 / Chapter 2.2.2.1.2. --- Drug administration --- p.36 / Chapter 2.2.2.1.3. --- Isolation of adipocytes --- p.37 / Chapter 2.2.2.1.4. --- Lipolysis measurement --- p.37 / Chapter 2.2.2.1.5. --- Data analysis --- p.38 / Chapter 2.2.2.2. --- RT-PCR --- p.38 / Chapter 2.2.2.2.1. --- Tissue preparation --- p.39 / Chapter 2.2.2.2.2. --- RNA extraction --- p.39 / Chapter 2.2.2.2.3. --- Reverse transcription (RT) --- p.40 / Chapter 2.2.2.2.4. --- Polymerase chain reaction (PCR) --- p.40 / Chapter 2.2.2.2.5. --- Agarose gel electrophoresis --- p.41 / Chapter 2.2.2.2.6. --- Data representation and analysis --- p.41 / Chapter 2.2.2.3. --- Western blotting --- p.42 / Chapter 2.2.2.3.1. --- Tissue preparation --- p.42 / Chapter 2.2.2.3.2. --- Protein extraction --- p.42 / Chapter 2.2.2.3.3. --- Western blotting --- p.42 / Chapter 2.2.2.3.4. --- Data representation and analysis --- p.43 / Chapter 2.3. --- Results --- p.43 / Chapter 2.3.1. --- Studies on the β-adrenoceptor-mediated lipolytic response in +m/+db and +db/+db mice --- p.43 / Chapter 2.3.1.1. --- Effect of β2-adrenoceptor agonist on lipolysis --- p.43 / Chapter 2.3.1.2. --- Effect of β3-adrenoceptor agonists and their antagonists on lipolysis --- p.44 / Chapter 2.3.1.3. --- Effect of non-selective β-adrenoceptor agonists and their antagonists on lipolysis --- p.45 / Chapter 2.3.1.4. --- Effect of modulators of intracellular cyclic nucleotide monophosphate on lipolysis --- p.46 / Chapter 2.3.1.5. --- Effect of exogenously delivered nitric oxide on lipolysis --- p.47 / Chapter 2.3.1.6. --- Gene expression of β-adrenoceptors in white adipose tissue --- p.47 / Chapter 2.3.1.7. --- Protein expression of β-adrenoceptors in white adipose tissue --- p.47 / Chapter 2.3.2. --- Effect of folic acid treatment on lipolysis --- p.48 / Chapter 2.3.2.1. --- Determination of body weight --- p.48 / Chapter 2.3.2.2. --- Effect of β2-adrenoceptor agonist on lipolysis --- p.48 / Chapter 2.3.2.3. --- Effect of β-adrenoceptor agonists on lipolysis --- p.49 / Chapter 2.3.2.4. --- Effect of non-selective β-adrenoceptor agonist on lipolysis --- p.50 / Chapter 2.3.2.5. --- Effect of modulators of intracellular cyclic nucleotide monophosphate on lipolysis --- p.51 / Chapter 2.3.2.6. --- Effect of exogenously delivered nitric oxide on lipolysis --- p.52 / Chapter 2.3.2.7. --- Gene expression of β-adrenoceptors in white adipose tissue --- p.52 / Chapter 2.3.2.8. --- Protein expression of β-adrenoceptors in white adipose tissue --- p.53 / Chapter 2.3.3. --- Effect of Lingzhi (water-extract) treatment on lipolysis --- p.54 / Chapter 2.3.3.1. --- Determination of body weight --- p.54 / Chapter 2.3.3.2. --- Lipolytic effect of forskolin --- p.54 / Chapter 3. --- Peroxisome Proliferator-Activated Receptor-y (PPAR-γ) --- p.91 / Chapter 3.1. --- Introduction --- p.91 / Chapter 3.1.1. --- Peroxisome proliferator-activated receptors --- p.91 / Chapter 3.1.1.1. --- Peroxisome proliferator-activated receptor-γ --- p.91 / Chapter 3.1.1.1.1. --- "PPAR-γ in obesity, lipid metabolism and type 2 diabetes" --- p.91 / Chapter 3.1.1.1.2. --- PPAR-γ in inflammation and atherosclerosis --- p.92 / Chapter 3.1.1.2. --- PPAR-γ and thiazolidinediones --- p.93 / Chapter 3.2. --- Materials and method --- p.95 / Chapter 3.2.1. --- Materials --- p.95 / Chapter 3.2.1.1. --- Composition of physiological salt solution --- p.95 / Chapter 3.2.1.2. --- Materials used in lipolysis experiment --- p.95 / Chapter 3.2.1.3. --- Materials used in RT-PCR --- p.95 / Chapter 3.2.1.4. --- Materials used in Western blotting --- p.95 / Chapter 3.2.2. --- Methods --- p.96 / Chapter 3.2.2.1. --- Lipolysis experiment --- p.96 / Chapter 3.2.2.2. --- RT-PCR --- p.96 / Chapter 3.2.2.3. --- Western blotting --- p.97 / Chapter 3.3. --- Results --- p.97 / Chapter 3.3.1. --- Effect of PPAR-γ agonists on lipolysis --- p.97 / Chapter 3.3.2. --- Gene expression of PPAR-γ in white adipose tissue --- p.97 / Chapter 3.3.3. --- Protein expression of PPAR-γ in white adipose tissue --- p.97 / Chapter 4. --- 3-Hydoxy-3-MethylgIutaryl Coenzyme A (HMG-CoA) Reductase --- p.106 / Chapter 4.1. --- Introduction --- p.106 / Chapter 4.1.1. --- Cholesterol metabolism and cardiovascular diseases --- p.106 / Chapter 4.1.2. --- Statins --- p.106 / Chapter 4.1.2.1. --- Modes of action --- p.107 / Chapter 4.1.2.2. --- Therapeutic efficacy of statins --- p.108 / Chapter 4.1.2.2.1. --- Diabetes --- p.108 / Chapter 4.1.2.2.2. --- Coronary artery disease --- p.109 / Chapter 4.1.3. --- Distribution and expression of HMG-CoA reductase --- p.109 / Chapter 4.2. --- Materials and method --- p.110 / Chapter 4.2.1. --- Materials --- p.110 / Chapter 4.2.1.1. --- Composition of physiological salt solution --- p.110 / Chapter 4.2.1.2. --- Materials used in lipolysis experiment --- p.110 / Chapter 4.2.1.3. --- Materials used in RT-PCR --- p.110 / Chapter 4.2.1.4. --- Materials used in Western blotting --- p.110 / Chapter 4.2.2. --- Methods --- p.110 / Chapter 4.2.2.1. --- Lipolysis experiment --- p.110 / Chapter 4.2.2.2. --- RT-PCR --- p.111 / Chapter 4.2.2.3. --- Western blotting --- p.111 / Chapter 4.3. --- Results --- p.112 / Chapter 4.3.1. --- Effect of statins on lipolysis --- p.112 / Chapter 4.3.2. --- Gene expression of HMG-CoA reductase in various internal organs --- p.112 / Chapter 4.3.3. --- Protein expression of HMG-CoA reductase in various internal organs --- p.113 / Chapter 5. --- Discussion --- p.122 / Chapter 5.1. --- β-adrenoceptor-mediated lipolysis --- p.122 / Chapter 5.2. --- Studies on peroxisome proliferator-activated receptor-γ --- p.140 / Chapter 5.3. --- Studies on HMG-CoA reductase --- p.142 / Chapter 5.4. --- Further studies --- p.147 / Chapter 5.5. --- Conclusions --- p.148 / Chapter 6. --- References --- p.152
143

Relationship between serum corticosteroid level and telomere length/telomerase activity in spleen cells of Balb/c mice.

January 2007 (has links)
Chiu, Wang Kei. / Thesis (M.Phil.)--Chinese University of Hong Kong, 2007. / Includes bibliographical references (leaves 95-110). / Abstracts in English and Chinese. / Abstract --- p.i / 摘要 --- p.iii / Contents --- p.v / Acknowledgements --- p.viii / Abbreviations --- p.ix / List of tables --- p.xii / List of figures --- p.xii / Chapter 1. --- Literature Review --- p.1 / Chapter 1.1 --- Cell cycle and chromosome replication --- p.1 / Chapter 1.2 --- Telomere-associated proteins --- p.4 / Chapter 1.3 --- Telomere repair protein --- p.6 / Chapter 1.4 --- Function of telomere --- p.9 / Chapter 1.5 --- Telomerase --- p.10 / Chapter 1.6 --- Factors affecting telomere length --- p.14 / Chapter 1.7 --- Stress and telomere length --- p.14 / Chapter 1.8 --- Definition of Stress --- p.16 / Chapter 1.9 --- Central nervous system components involved in stress response --- p.17 / Chapter 1.10 --- Glucocorticoid --- p.17 / Chapter 1.11 --- Physiological effects under the activation of stress system --- p.19 / Chapter 1.12 --- Effects of chronic hyperactivation of the stress system --- p.20 / Chapter 1.13 --- Hypothesis --- p.23 / Chapter 2. --- Materials and Methods --- p.24 / Chapter 2.1 --- Materials --- p.24 / Chapter 2.2 --- Experiment animals --- p.25 / Chapter 2.3 --- Methods --- p.26 / Chapter 2.3.1 --- Treatment schedule --- p.26 / Chapter 2.3.2 --- Organ extraction and serum preparation --- p.27 / Chapter 2.4 --- Serum corticosteroid assay --- p.27 / Chapter 2.5 --- Telomere length assay --- p.30 / Chapter 2.5.1 --- Genomic DNA extraction --- p.30 / Chapter 2.5.2 --- Genomic DNA digestion --- p.31 / Chapter 2.5.3 --- Southern blotting procedure --- p.32 / Chapter 2.6 --- Telomeric Repeat Amplification Protocol (TRAP) assay --- p.37 / Chapter 2.6.1 --- Extract preparation and protein concentration quanititation --- p.38 / Chapter 2.6.2 --- Real-time PCR reaction --- p.39 / Chapter 2.6.3 --- Melt Curve --- p.41 / Chapter 2.7 --- Detection of mouse telomerase reverse transcriptase component (mTERT) mRNA expression by reverse transcriptase- polymerase chain reaction (RT-PCR) --- p.42 / Chapter 2.7.1 --- Total RNA extraction --- p.42 / Chapter 2.7.2 --- RT-PCR --- p.44 / Chapter 2.7.3 --- Agarose gel electrophoresis of RT-PCR products --- p.45 / Chapter 2.8 --- Detection of mouse TERT (mTERT) by Western blotting --- p.46 / Chapter 2.8.1 --- Nuclear protein extraction --- p.46 / Chapter 2.8.2 --- Sodium dodecyl sulphate polyacrylamide gel electrophoresis (SDS-PAGE) --- p.47 / Chapter 2.9 --- Statistics --- p.49 / Chapter 3. --- Results --- p.51 / Chapter 3.1 --- Body and spleen weights of study animals --- p.51 / Chapter 3.2 --- Serum corticosterone level --- p.54 / Chapter 3.3 --- Telomere lengths of spleen --- p.54 / Chapter 3.4 --- Telomerase activity of spleen tissue --- p.58 / Chapter 3.5 --- Correlation between serum corticosterone level and telomere length --- p.65 / Chapter 3.6 --- Correlation between serum corticosterone level and telomerase activity --- p.66 / Chapter 3.7 --- Correlation between telomere length and telomerase activity --- p.67 / Chapter 3.8 --- Detection of telomerase reverse transcriptase component (mTERT) mRNA expression by RT-PCR --- p.69 / Chapter 3.9 --- Detection of mTERT by Western blotting --- p.72 / Chapter 3.10 --- Correlation between serum corticosterone level and mTERT mRNA /protein expression --- p.75 / Chapter 4. --- Discussion --- p.77 / Chapter 4.1 --- Serum corticosterone level in mice --- p.78 / Chapter 4.2 --- Mice body weight and spleen weight --- p.80 / Chapter 4.3 --- Telomere lengths in the spleen tissue --- p.83 / Chapter 4.4 --- Telomerase activity in spleens --- p.84 / Chapter 4.5 --- Correlation between serum corticosterone level and telomere length --- p.87 / Chapter 4.6 --- Correlation between serum corticosterone level and telomerase activity --- p.89 / Chapter 4.7 --- Mouse telomerase reverse transcriptase component (mTERT) mRNA expression --- p.89 / Chapter 4.8 --- Expression of mTERT protein --- p.90 / Chapter 4.9 --- Conclusion --- p.92 / Chapter 5. --- References --- p.95 / Chapter 6. --- Appendix --- p.111
144

Planejamento, síntese e avaliação farmacológica de novos derivados ftalimídicos inibidores de histona deacetilase para anemia falciforme /

Pavan, Aline Renata. January 2018 (has links)
Orientador: Jean Leandro dos Santos / Banca: Chung, Man Chin / Banca: Simone Kashima Haddad / Resumo: A reativação da expressão gênica de gama-globina e consequente produção de hemoglobina fetal (HbF) por mecanismos epigenéticos é uma valiosa intervenção terapêutica na anemia falciforme. Estudos recentes mostram que a inibição da enzima Histona Deacetilase (HDAC), principalmente HDAC-1 e HDAC-2, mostrou ser uma estratégia promissora em promover o aumento da expressão gênica de gama-globina e a produção de HbF sem causar alteração no ciclo e proliferação celular. Neste trabalho foram planejadas por modelagem molecular novos compostos inibidores de HDAC 1 e 2. Os estudos de ancoragem molecular revelaram a forma como estes compostos interagem com a HDAC-2, sendo a subunidade N-(2-aminofenil)benzamida responsável por interagir com o átomo de zinco presente no sítio ativo. Durante o processo de otimização das estruturas, os valores de docking score passaram de -9,8 para - 12,3, indicando melhores interações com o receptor. Onze compostos inéditos foram sintetizados e caracterizados por métodos analíticos. Os estudos enzimáticos mostraram atividade inibitória dos novos compostos variaram de 83 à 96% para HDAC-1, 83 à 94% para HDAC-2 e 82 à-89% para HDAC-3. O composto (22) (4-(4-aminofenetil)-N-(2-aminofenil)benzamida) foi um dos mais ativos apresentando, na concentração de 10 μM, atividade inibitória contra as HDACs 1 e 2 com valores superiores a 90%. Estes resultados mostram que os compostos planejados neste trabalho são potenciais inibidores de HDAC, sendo a molécula (22) a mais ... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: Reactivation of gamma-globin gene expression and fetal hemoglobin (HbF) production through epigenetic mechanisms are valuable strategy to sickle cell anemia treatment. Early studies have demonstrated that histone deacetylase inhibition, especially HDAC-1 and HDAC-2, is a promising strategy to increase gamma-globin gene expression and HbF production without alteration in cell cycle or cell proliferation. At this work it was designed, by molecular modeling, new compounds HDAc 1 and 2 inhibitors. The molecular modeling studies has demonstrated how these compounds interacts with HDAC-2, being the subunit N-(2-aminophenyl)benzamide responsible for interact with the zinc atom of active site. During the optimization process, the docking score values hava changed from -9,8 to -12,3, which indicates better interactions with the receptor. It was synthesized and characterized eleven new compounds. Enzimatic assays have demonstrated that the enzymatic inhibition of the compounds varied from 83 to 96% against HDAC 1, 83-94% against HDAC 2 and 82-89% of HDAC 3. Compound (22) (4-(4-aminophenetyl)-N-(2-aminophenyl) benzamide was one of the most promisor among all compounds. At 10uM it was able to inhibit HDAC 1 and 2 more than 90%. These data has demonstrated that the design compounds in this work are potencial inhibitors of HDAC, being...(Complete abstract click electronic access below) / Mestre
145

Prepulse inhibition and the acoustic startle response in nine inbred mouse strains [electronic resource] / by Jennifer Robin O'steen.

O'steen, Jennifer Robin. January 2003 (has links)
Title from PDF of title page. / Document formatted into pages; contains 18 pages. / Thesis (Au.D.)--University of South Florida, 2003. / Includes bibliographical references. / Text (Electronic thesis) in PDF format. / ABSTRACT: This study examined the effects of genetic background on the acoustic startle response (ASR) and its modulation by prepulse inhibition (PPI) by comparing nine inbred strains of mice. The ASR, a jerk-like motor reflex, is elicited by bursts of noise or tones with sound pressure levels of 80-90 dB and greater. PPI is a type of modulation of the ASR, requires no training, and results in observable response in both mice and humans. Data were obtained from nine inbred mouse strains, sixteen per strain, which were shipped at approximately 3-5 weeks old from The Jackson Laboratory. In general, ASRs were generally smaller when the startle stimulus was less intense. PPI was relatively weak for the 4 kHz prepulse, and stronger with prepulses of 12 kHz and 20 kHz. However, means varied widely across strains for both ASR and PPI, suggesting a strong influence of genetic background on these behaviors. / ABSTRACT: In addition to genetic influences, peripheral hearing loss and central auditory processing factors must be taken into consideration. / System requirements: World Wide Web browser and PDF reader. / Mode of access: World Wide Web.
146

Contribution à l'étude de la mémoire à long terme chez la souris

Peters, Elisabeth January 1975 (has links)
Doctorat en sciences psychologiques / info:eu-repo/semantics/nonPublished
147

Effect of in vitro culture media and assisted hatching techniques on mice embryo survival rate following cryopreservation

Serota, Nthabiseng Ruth 18 May 2018 (has links)
MSCAGR (Animal Science) / Department of Animal Science / This study determined the effects of in vitro culture media (Ham’s F10 and TCM199) and assisted hatching techniques (laser or mechanical) on mice embryo survival following cryopreservation. Pure strain C57BL/6 (B6) female (50) and strain BALB /c (C) Male (25) mice were crossed to produce F1 generation of females which were injected for follicular growth and super ovulation at 6 weeks of age and from which embryos were produced 21 h later through in vivo fertilization. Embryos were randomly divided into Petri dishes with different culture media, and the development of embryos was assessed until the morula stage. At the morula stage, selected embryos were assisted to hatch using different techniques, and then cryopreserved in liquid nitrogen using the slow freezing method for a period of 1 week. After 1 week of cryopreservation, the embryos were thawed and cultured in the two different in vitro culture media for 72 hours. Thereafter, the numbers of embryos hatched or survived were recorded after 24 h, 48 h and 72 h. Data was analyzed using ANOVA in Minitab Software Version 16 (2010). Significant difference in embryo quality development was observed between in vitro culture media and stage of embryo development (P<0.05). In the TCM-199 in vitro culture medium, embryo quality development yielded 72, 69 and 69% from day 1 to day 3, while in Ham’s F10 embryo quality development yielded 68, 63 and 60% respectively. Relative to the control (18.1%) assisted hatching improved hatchability significantly (P<0.05) in the order laser (23.6%)>, mechanical (20.8%). There was significant (P<0.01) interaction between assisted hatching techniques and evaluation time, whereby laser assisted hatching was most successful at 48 h (42.0%) while mechanical assisted hatching was most successful at 72 h (36.8%). Cryopreservation reduced the embryo survival compared to fresh embryos. In conclusion laser was the best assisted hatching technique, while TCM-199 was the better medium for in vitro culture of embryo. / NRF
148

Immune stimulation with short-term exposure to extremely low frequency electromagnetic fields in mice (Mus. musculus)

Wiese, Michelle Kim January 2013 (has links)
Thesis (M. Tech. (Biomedical Technology)) -- Central University of technology, Free State, 2013 / Electromagnetic fields are present wherever electricity is created. The frequency range of these electromagnetic fields is from extremely low to extremely high. The fields present in domestic areas fall within the extremely low frequency range. These fields are created by domestic electrical appliances and telecommunication. There has been much debate on the effect of exposure to these fields on human health. Research has not yet been able to prove adverse effect of these fields on human health. In fact, the benefits of magneto therapy has been recognized and used for several decades. Recently a specific electromagnetic signal has been under investigation for its ability to stimulate the immune response. This signal is produced by a patented generator, called Immunent Activator. Studies performed with the Immunent Activator signal on farm animals revealed increased feed conversion and decreased intestinal lesions of animals with intestinal infections. Most of the research was performed on fish and fowls and evidence of similar findings in mammals is lacking. In the current study, mice were exposed to the Immunent BV signal for seven days, after which immune cell counts were performed and compared to the immune cell counts of a control group of mice which received no electromagnetic exposure. It was found that the T-lymphocyte population of immune cells in the exposed group of mice was statistically significantly higher than that of the control group. The neutrophil count was statistically significantly lower in the exposed group compared to the control group. These findings revealed evidence of immune stimulation in the mice which were exposed to the Immunent Activator signal. Suggestions for further research could be made with regard to specific mechanisms of immune stimulation. The findings of this and other related studies hold benefits for the farming and health industry.
149

Over-Expression of BDNF Does Not Rescue Sensory Deprivation-Induced Death of Adult-Born Olfactory Granule Cells

Unknown Date (has links)
It is of interest to understand how new neurons incorporate themselves into the existing circuitry of certain neuronal populations. One such population of neurons is that which are born in the subventricular zone (SVZ) and migrate to the olfactory bulb where they differentiate into granule cells. Another area of interest is the role of brain-derived neurotrophic factor (BDNF) on the survival and overall health of these neurons. This study aimed to test whether or not BDNF is a survival factor for adult-born granule cells. Here were utilized a transgenic mouse model over-expressing BDNF under the α- calcium/calmodulin-dependent protein kinase II (CAMKIIα) promoter, and tested its effect on olfactory granule cells under sensory deprived conditions. Results from this experiment indicated that there was no significant difference in cell death or cell survival when comparing transgenic and wild type animals. We concluded that BDNF is not a survival factor for adult-born granule cells. / Includes bibliography. / Thesis (M.S.)--Florida Atlantic University, 2016. / FAU Electronic Theses and Dissertations Collection
150

Of Mice, Men and Memories: The Role of the Rodent Hippocampus in Object Recognition

Unknown Date (has links)
Establishing appropriate animal models for the study of human memory is paramount to the development of memory disorder treatments. Damage to the hippocampus, a medial temporal lobe brain structure, has been implicated in the memory loss associated with Alzheimer’s disease and other dementias. In humans, the role of the hippocampus is largely defined; yet, its role in rodents is much less clear due to conflicting findings. To investigate these discrepancies, an extensive review of the rodent literature was conducted, with a focus on studies that used the Novel Object Recognition (NOR) paradigm for testing. The total amount of time the objects were explored during training and the delay imposed between training and testing seemed to determine hippocampal recruitment in rodents. Male C57BL/6J mice were implanted with bilateral dorsal CA1 guide cannulae to allow for the inactivation of the hippocampus at discrete time points in the task. The results suggest that the rodent hippocampus is crucial to the encoding, consolidation and retrieval of object memory. Next, it was determined that there is a delay-dependent involvement of the hippocampus in object memory, implying that other structures may be supporting the memory prior to the recruitment of hippocampus. In addition, when the context memory and object memory could be further dissociated, by altering the task design, the results imply a necessary role for the hippocampus in the object memory, irrespective of context. Also, making the task more perceptually demanding, by requiring the mice to perform a two-dimensional to three-dimensional association between stimuli, engaged the hippocampus. Then, in the traditional NOR task, long and short training exploration times were imposed to determine brain region activity for weak and strong object memory. The inactivation and immunohistochemistry findings imply weak object memory is perirhinal cortex dependent, while strong object memory is hippocampal-dependent. Taken together, the findings suggest that mice, like humans, process object memory on a continuum from weak to strong, recruiting the hippocampus conditionally for strong familiarity. Confirming this functional similarity between the rodent and human object memory systems could be beneficial for future studies investigating memory disorders. / Includes bibliography. / Dissertation (Ph.D.)--Florida Atlantic University, 2016. / FAU Electronic Theses and Dissertations Collection

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