1 |
Helicobacters of rodents /Beckwith, Catherine S., January 2000 (has links)
Thesis (Ph. D.)--University of Missouri--Columbia, 2000. / "December 2000." Typescript. Vita. Includes bibliographical references (leaves 95-112). Also available on the Internet.
|
2 |
Helicobacters of rodentsBeckwith, Catherine S., January 2000 (has links)
Thesis (Ph. D.)--University of Missouri--Columbia, 2000. / Typescript. Vita. Includes bibliographical references (leaves 95-112). Also available on the Internet.
|
3 |
Molecular and cellular investigation of rodent brains by magnetic resonance imagingLee, Yik-hin., 李易軒. January 2012 (has links)
Magnetic Resonance Imaging (MRI) is a non-ionizing imaging modality that can provide images with excellent soft tissue contrast at high resolution. In particular, molecular and cellular MRI is a powerful imaging method that could provide a non-invasive way for assessing specific biological processes in vivo in living organisms. The ability to monitor and track biological structures and processes down to molecular and cellular level and the possibility to probe the development, survival, migration, and differentiation of cells in vivo, has opened up new ways for scientists to investigate the fundamental mechanisms of health and diseases. In this dissertation, novel applications of conventional MR contrast agents to study specific biological structures and processes are demonstrated.
First, the potential of manganese enhanced MRI (MEMRI) for in vivo tract tracing and assessment of neuroarchitecture was investigated. Manganese was intracortically infused into the visual cortex along the border of the primary and secondary visual cortex and then imaged 8 and 24 hours later. A dynamic migratory path of manganese from the infusion site through the corpus callosum to the contralateral hemisphere was observed. Also, layer specific enhancement on the contralateral cortex and the connection of the visual cortex with other brain structures were shown and the results were consistent with established anatomical data. Secondly, MEMRI was performed to probe in vivo neuronal changes in the rodent brain following 72-hour rapid eye movement sleep deprivation. Significant reduction in manganese uptake was observed in the cortical and hippocampal region in the sleep deprived animals when compared to the normal group. In particular, the dentate gyrus substructure in the hippocampus exhibited the least uptake. This indicated the functional vulnerability of the hippocampus and the cortex to sleep deprivation. Lastly, in vivo tracking of endogenous neural stem and progenitor cell migration during neurogenesis in neonatal rat brain was performed by micron sized iron oxide particles (MPIO) labeling. Susceptibility weighted imaging was used for image processing to highlight the susceptibility contrast induced by the iron oxide particles. MPIO-labeled cells induced contrast was clearly enhanced in the susceptibility weighted images, particularly at day 3 after MPIO injection in which the MPIO-labeled NPCs became more dispersed in the olfactory bulb. The ventral migratory pathway of endogenous neural stem and progenitor cells, which could not be easily observed in conventional T2*W imaging, couldalsobe detected.
Overall, various biological systems and processes have been successfully interrogated using MR contrast agents. Through these studies, the versatility and power of molecular and cellular MRI have been demonstrated. Looking ahead, the rapid development and combination of different molecular and cellular imaging techniques would certainly revolutionize the way we study health and diseases. In the end, this could foster our understanding of basic life sciences and hence improve the quality of healthcare. / published_or_final_version / Electrical and Electronic Engineering / Master / Master of Philosophy
|
4 |
Preclinical assessment of the immunosuppressive properties of an anti-CD4 monoclonal antibody (MAB) in an allogeneic foetal rat pancreatic transplantation modelMuller, Christo John Frederick 12 1900 (has links)
Dissertation (PhD)--Stellenbosch University, 2004. / ENGLISH ABSTRACT: Introduction
Despite advances in insulin therapy, the side effects associated with diabetes mellitus still
remain. Pancreas transplantation has benefited diabetics with end-stage renal failure by
reversing the diabetic state and preventing or reversing the progression of diabetes associated
diseases. Currently the side effects associated with lifelong immunosuppression preclude
pancreas transplantation as a viable treatment option for both type I and II diabetics.
In the laboratory, transplanted rat foetal pancreata have been shown to be able to reverse the
clinical signs of streptozotocin-induced diabetes in an isogeneic model. Reversal of diabetes
by allogeneic foetal rat pancreas transplantation, although possible has proved to be more
difficult due to fierce rejection of the grafts and the diabetogenic effects of conventional
immunosuppressants.
Aims
One of the goals, focus and intentions of this laboratory study in rodents, is to contribute new
information to the scientific literature. The potential to “reverse” the diabetic state by
allogeneic foetal pancreatic transplantation, was the main stimulus for this study.
Methods
Foetal pancreata of 16-18 days gestation were transplanted into a surgically prepared renal
subcapsular space. Immunosuppressive protocols used to prevent rejection of the allogeneic
foetal rat pancreata included donor specific transfusion (DST), cyclosporine [a calcineurin
inhibitor (CsA)], mycophenolate mofetil [a purine syntase inhibitor (MMF)], and a mouse
anti-rat CD4 monoclonal antibody (W3/25). Immunosuppressants were used as
monotherapies and in combination. Results
Isogeneic foetal rat pancreas transplantation resulted in the growth and development of
mature insulin producing islets of Langerhans at the site of engraftment. Allogeneic foetal
pancreatic transplantation without immunosuppression resulted in complete rejection of the
grafts at 14 days post-transplantation.
Histological assessment of allografts at 14 and 30 days post-transplantation showed that CsA
was able to prevent acute rejection in our rat models although graft scores and survival were
improved if CsA was combined with MMF. Intraperitoneal anti-CD4 monoclonal injections
were well tolerated, and if given daily effectively prolonged graft survival up to 30 days.
Combining DST with anti-CD4 and CsA induction therapy provided long-term graft survival
without daily immunosuppression. This combination, together with allogeneic foetal rat
pancreas transplantation, was effective in reversing the clinical signs of experimentally
induced diabetes. To my knowledge these are the first published results in which reversal of
streptozotocin induced diabetes was achieved by fully MHC mismatched foetal rat pancreatic
transplantation.
Conclusion
Foetal rat pancreatic transplantation is a potential source of endocrine replacement, which,
with effective immunosuppression allows for the development of functional islets able to
reverse the clinical signs of experimentally induced diabetes in an allogeneic rat model. An
unique immunosuppressive protocol, with potential clinical relevance in the human,
combines anti-CD4 mAb, CsA and DST induction therapy, which alleviates the burden of
daily immunosuppression and associated side effects. / AFRIKAANSE OPSOMMING: Inleiding
Ten spyte van die vordering met modeme insulienterapie bly die newe-effekte, waarmee
diabetes mellitus geassosieer is, steeds ‘n probleem vir diabete. Diabetiese pasiente met
eindstadium nierversaking trek geweldig voordeel uit nier-pankreasoorplantings wat die
diabetes omkeer en die progressie van diabetesverwantesiektes voorkom of selfs omkeer.
Die newe-effekte van lewenslange immuunonderdrukking skakel pankreasoorplanting uit as
‘n lewensvatbare behandelingsopsie vir tipe I of II diabete.
In ‘n streptozotosien-gei'nduseerde diabetiese rotmodel kan isogenei'ese fetale
pankreasoorplanting die kliniese tekens van diabetes omkeer. Die omkering van
streptozotosien-gei'nduseerde diabetes deur allogeneiese fetale pankreasoorplanting behoort
moontlik te wees indien verwerping en die diabetogeniese newe-effekte van konvensionele
immuunonderdrukkers oorkom word.
Doelstellings
Een van die mikpunte, fokusse en oogmerke van hierdie laboratorium studie in knaagdiere, is
om ‘n betekenisvolle bydrae tot nuwe kennis in die wetenskaplike literatuur, te maak. Die
potensiaal om die diabetiese toestand deur allogeneiese fetale pankeasoorplanting om te keer,
was die hoof stimulus vir die studie.
Metodes
Fetale rotpankreata van 16-18 dae gestasie was in ‘n chirurgies voorbereide spasie onder die
nierkapsel oorgeplant. Immuunonderdrukkende protokolle, vir die voorkomming van
verwerping van die allogeneiese fetale pankreasoorplantings, het donorspesifiekeoortappings
(DST), siklosporien [‘n kalsineurien inhibitor (CsA)], mikofenolaat mofetiel [‘n purien sintase inhibitor (MMF)] en ‘n anti-rot CD4 monoklonale antiliggaam (W3/25) ingesluit. Die
immuunonderdrukkers is as mono- of as kombinasieterapie gebruik.
Resultate
IsogeneTese fetale rotpankreasoorplanting het tot die ontwikkeling van volwasse
insulienproduseerende eilande van Langerhans gelei, wat die kliniese tekens van
streptozotosien-gei'nduseerde diabetes kon omkeer.
Allogenei'ese fetale rotpankreasoorplanting sonder immuunonderdrukking het tot algehele
verwerping van die oorplanting binnel4 dae na oorplanting gelei.
Histologiese beoordeling van die oorplantings 14 en 30 dae na oorplanting het getoon dat
CsA akute verwerping van fetale pankreasoorplantings in die rotmodelle voorkom. Indien
CsA met MMF gekombineer word, word die oorplantings-telling en oorlewing verbeter.
Intraperitoneale anti-CD4 monoklonale inspuitings was goed verdra, en indien daagliks
toegedien, het dit die oorlewing van die pankreasoorplantings effektief tot 30 dae verleng.
Die kombinasie van DST, anti-CD4 en CsA induksieterapie het tot langtermyn oorlewing van
die pankreasoorplantings gelei sonder verdere daaglikse immuunonderdrukking. Die
induksieterapie in kombinasie met allogenei'ese fetale pankreasoorplanting was effektief in
die omkering van die kliniese tekens van streptozotosien-gei'nduseerde diabetes in die rot.
Hierdie is, sover ek weet, die eerste keer dat omkering van streptozotosien-gei'nduseerde
diabetes suksesvol met ‘n volledige MHC onverenigbare allogenei'ese fetale
pankreasoorplanting behaal is.
Gevolgtrekkings
Fetale rotpankreasoorplanting is ‘n potensiele bron vir endokrien vervangingsterapie, wat met
effektiewe immuunonderdrukking tot die ontwikkeling van funksionele eilande van
Langerhans lei, wat die vermoe het om die kliniese tekens van experimenteel-ge'induseerde diabetes in ‘n allogeneiese rotmodel om te keer. ‘n Unieke immuunonderdrukkingsprotokol,
met kliniese relevansie, kombineer DST met anti-CD4 mAb en CsA induksieterapie wat die
las van daaglikse immuunonderdrukking en die geassosieerde newe-effekte van
konvensionele immuunonderdrukking verlig.
|
5 |
Uncovering the role of the rodent dorsal hippocampus in spatial and object memory retrievalUnknown Date (has links)
Male C7BL/6J mice were implanted with bilateral dorsal CA1 guide cannulae. After confirming that intrahippocampal microinfusion of muscimol impaired hippocampal function, demonstrated by impaired performance in the Morris water maze, the influence of intrahippocampal muscimol was tested in the Novel Object Recognition paradigm. During a test session 24 h after the last habituation/sample session, mice were presented with one familiar object and one novel object. Successful retention of object memory was inferred if mice spent more time exploring the novel object than the familiar object. Results demonstrate that muscimol infused into dorsal CA1 region prior to the test session eliminates novel object preference, indicating that the hippocampus is necessary for the retrieval of this non-spatial memory - a topic that has garnered much debate. Understanding the similarities between rodent and human hippocampal function could enable future animal studies to effectively answer questions about diseases and disorders affecting human learning and memory. / by Lisa Rios. / Thesis (M.A.)--Florida Atlantic University, 2011. / Includes bibliography. / Electronic reproduction. Boca Raton, Fla., 2011. Mode of access: World Wide Web.
|
6 |
Interactions of ethanol and chloroquine in the protein-mulnourished male sprague dawley rats : haemotological, biochemical and testicular effectsMbajiorgu, Ejikeme Felix January 2010 (has links)
Thesis (PH.D. (Medical Sciences)) --University of Limpopo, 2010 / Refere to document
|
7 |
Acute and chronic toxicity of the flavonoid-containing plant, Artemisia afra in rodents.Mukinda, James Tshikosa January 2005 (has links)
The aim of this study was to investigate the possible toxicity of the flavonoid-containing plant, Artemisia afra and especially establish the safety of the aqueous extract of this plant after acute and chronic administration to mice and rats respectively.
|
8 |
Acute and chronic toxicity of the flavonoid-containing plant, Artemisia afra in rodents.Mukinda, James Tshikosa January 2005 (has links)
The aim of this study was to investigate the possible toxicity of the flavonoid-containing plant, Artemisia afra and especially establish the safety of the aqueous extract of this plant after acute and chronic administration to mice and rats respectively.
|
9 |
Acute and chronic toxicity of the flavonoid-containing plant, Artemisia afra in rodentsMukinda, James Tshikosa January 2005 (has links)
Magister Scientiae - MSc / The aim of this study was to investigate the possible toxicity of the flavonoid-containing plant, Artemisia afra and especially establish the safety of the aqueous extract of this plant after acute and chronic administration to mice and rats respectively. / South Africa
|
10 |
Functional magnetic resonance imaging (fMRI) of rodent visual and auditory systemXing, Kai, 邢锴 January 2011 (has links)
Functional MRI or Functional Magnetic Resonance Imaging (fMRI) is a type of specialized MRI scan which measures the hemodynamic response related to neural activity in the brain or spinal cord of humans and animals. Due to its relatively low invasiveness, absence of radiation exposure, and relatively wide availability, functional MRI has come to dominate the brain mapping field since the early 1990s. The objective of this thesis work is to develop and apply functional MRI methods at 7 Tesla, for in vivo investigation of rodent visual and auditory system. Firstly, the development of the rat visual pathway was studied by blood oxygenation level–dependent (BOLD) contrast from the time of eyelid opening (P14) to adulthood (P60) in normal rat brain. By studying BOLD-fMRI measurements in the normal brain superior colliculus (SC), we determined that the regional BOLD response undergoes a systematic increase in amplitude especially over the third postnatal week.
Secondly, the potential for plasticity of the rodent superior colliculus (SC) was studied using BOLD fMRI. By studying BOLD-fMRI measurements in the SC of three groups of rats (normal, HI-injured with left SC partially damaged and HI-injured with left SC completely damaged), we can evaluate the extent of plastic changes, compensatory and transneuronal plasticity after varying degrees of SC injury. We also applied BOLD-fMRI using very short repetition time (TR) of 0.2s on rats to measure the difference in response temporal dynamics between the SC and LGN, which has not been measured conclusively or with high temporal resolution. The primary finding in this study is that there is an approximately 0.8s difference between the BOLD responses of the rat contralateral SC and LGN to the visual stimuli. In addition, the amplitude of the SC response is larger than that of the LGN. Thirdly, BOLD-fMRI is used to measure the SC hemodynamic responses, in normal adult Sprague-Dawley (SD) rats, during a dynamic visual stimulus similar to those used in long-range apparent motion studies. The stimulation paradigm mimic effective speeds of motion between 7 and 164?/s, the results suggest that the SC is sensitive to slow moving visual stimuli but the hemodynamic response is reduced at higher speeds.
Finally, BOLD-fMRI is used to study hemodynamic response temporal dynamics in the superior colliculus (SC) and inferior colliculus (IC) following visual and auditory associated stimulation. Our results show the baselines of SC BOLD signal (in two sides) increase during the ON period of auditory stimulation, which demonstrate that auditory stimulation can increase ROI activation signal intensity in superior colliculus (SC). The previous dominant theory is that individual senses each have separate areas of the brain dedicated to processing each sense, while the individual sense perceptions are integrated together to produce a multi-sensory experience. As a result of new research over the past several years, however, this view has been challenged by studies showing that processing in the visual area of the brain can be directly influenced by hearing and touch. All these discoveries represent a new view of how the brain is actually organized. / published_or_final_version / Electrical and Electronic Engineering / Master / Master of Philosophy
|
Page generated in 0.1758 seconds