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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.
1

Premature aging of the lungs of the offspring induced by maternal nicotine exposure during gestation and lactation: protective effects of tomato juice

Mutemwa, Muyunda January 2012 (has links)
<p>Tobacco smoking during pregnancy and lactation is a common habit and accounts for a significant percentage of fetal morbidity and mortality worldwide. The offspring is as a result exposed to nicotine through the blood and the milk of the mother. Nicotine is thus expected to interact with the developing fetus and the offspring of mothers who smoke or use NRT for smoking cessation, resulting in the interference with normal fetal and neonatal lung development. Maternal cigarette smoke or nicotine exposure produces adverse effects in the lungs of offspring, these include / intrauterine growth retardation, low birth weight, premature birth, reduced pulmonary function at birth, and a high occurrence of respiratory illnesses after birth. This study aimed at investigating&nbsp / the effects of maternal nicotine exposure during gestation and lactation on lung development in the offspring / to establish whether tomato juice can have protective effects on the fetal lung&nbsp / development and function in the offspring / and to determine if nicotine cases premature aging of the lungs of the offspring. It was therefore shown that maternal exposure to nicotine during&nbsp / gestation and lactation ad no significant effect on the growth parameters of the offspring. Maternal nicotine exposure during gestation and lactation had no effect on the growth parameters of&nbsp / the offspring, but resulted in compromised lung structure and function. The morphometric results demonstrated decrease in alveolar number, increase in alveolar size, and decrease in lung&nbsp / parenchyma of the nicotine exposed animals showing a gradual deterioration of the lung parenchyma. Structural alterations include emphysematous lesions, where the latter was&nbsp / accompanied by an increase in alveolar size (Lm), and a decrease in the tissue volume of the lung parenchyma. Thickening of alveolar walls was also evident and serves as an indication of&nbsp / remodeling of the extracellular matrix, also a characteristic of emphysema. A consequence of the gradual deterioration of the lung parenchyma is a decrease in the alveolar surface area available for gas exchange. The present study showed that the emphysematous lesions were conceivably a result of a reduced rate of cell proliferation accompanied by the increase in&nbsp / senescent cells numbers in the alveolar walls of the exposed offspring. The data of this study suggests that maternal nicotine exposure during gestation and lactation induces premature&nbsp / aging of the lungs of the offspring rendering the lungs of the offspring more susceptible to disease later in life. Since these structural changes occurred later in the life of the offspring and long&nbsp / after nicotine withdrawal, it is suggested that it is programmed during gestation and lactation. Smoking and NRT result in an increased load of oxidants in the mother and fetus. It also reduces&nbsp / the level of anti-oxidants and thereby compromising the ability of the mother to protect the fetus. It is hypothesized that this oxidant-antioxidant imbalance will program the lungs to age&nbsp / prematurely. The supplementation of the mother&rsquo / s diet with tomato juice, rich in lycopene, other anti-oxidants such as vitamin C, as well as phytonutrients protected the lungs of the offspring&nbsp / against the adverse effects of maternal nicotine exposure. This supports the hypothesis mentioned above. The study further showed that the effects of grand-maternal nicotine exposure during gestation and lactation on the lungs of the F1 offspring is also transferred to the F2 offspring. This is most likely via the paternal and maternal germ line. Since tomato juice supplementation of the mother&rsquo / s diet with tomato juice prevented&nbsp / the adverse effects of maternal nicotine exposure on the lungs of the offspring, it is conceivable that it will prevent transfer of these changes to the F2 generation.&nbsp / </p>
2

Premature aging of the lungs of the offspring induced by maternal nicotine exposure during gestation and lactation: protective effects of tomato juice

Mutemwa, Muyunda January 2012 (has links)
<p>Tobacco smoking during pregnancy and lactation is a common habit and accounts for a significant percentage of fetal morbidity and mortality worldwide. The offspring is as a result exposed to nicotine through the blood and the milk of the mother. Nicotine is thus expected to interact with the developing fetus and the offspring of mothers who smoke or use NRT for smoking cessation, resulting in the interference with normal fetal and neonatal lung development. Maternal cigarette smoke or nicotine exposure produces adverse effects in the lungs of offspring, these include / intrauterine growth retardation, low birth weight, premature birth, reduced pulmonary function at birth, and a high occurrence of respiratory illnesses after birth. This study aimed at investigating&nbsp / the effects of maternal nicotine exposure during gestation and lactation on lung development in the offspring / to establish whether tomato juice can have protective effects on the fetal lung&nbsp / development and function in the offspring / and to determine if nicotine cases premature aging of the lungs of the offspring. It was therefore shown that maternal exposure to nicotine during&nbsp / gestation and lactation ad no significant effect on the growth parameters of the offspring. Maternal nicotine exposure during gestation and lactation had no effect on the growth parameters of&nbsp / the offspring, but resulted in compromised lung structure and function. The morphometric results demonstrated decrease in alveolar number, increase in alveolar size, and decrease in lung&nbsp / parenchyma of the nicotine exposed animals showing a gradual deterioration of the lung parenchyma. Structural alterations include emphysematous lesions, where the latter was&nbsp / accompanied by an increase in alveolar size (Lm), and a decrease in the tissue volume of the lung parenchyma. Thickening of alveolar walls was also evident and serves as an indication of&nbsp / remodeling of the extracellular matrix, also a characteristic of emphysema. A consequence of the gradual deterioration of the lung parenchyma is a decrease in the alveolar surface area available for gas exchange. The present study showed that the emphysematous lesions were conceivably a result of a reduced rate of cell proliferation accompanied by the increase in&nbsp / senescent cells numbers in the alveolar walls of the exposed offspring. The data of this study suggests that maternal nicotine exposure during gestation and lactation induces premature&nbsp / aging of the lungs of the offspring rendering the lungs of the offspring more susceptible to disease later in life. Since these structural changes occurred later in the life of the offspring and long&nbsp / after nicotine withdrawal, it is suggested that it is programmed during gestation and lactation. Smoking and NRT result in an increased load of oxidants in the mother and fetus. It also reduces&nbsp / the level of anti-oxidants and thereby compromising the ability of the mother to protect the fetus. It is hypothesized that this oxidant-antioxidant imbalance will program the lungs to age&nbsp / prematurely. The supplementation of the mother&rsquo / s diet with tomato juice, rich in lycopene, other anti-oxidants such as vitamin C, as well as phytonutrients protected the lungs of the offspring&nbsp / against the adverse effects of maternal nicotine exposure. This supports the hypothesis mentioned above. The study further showed that the effects of grand-maternal nicotine exposure during gestation and lactation on the lungs of the F1 offspring is also transferred to the F2 offspring. This is most likely via the paternal and maternal germ line. Since tomato juice supplementation of the mother&rsquo / s diet with tomato juice prevented&nbsp / the adverse effects of maternal nicotine exposure on the lungs of the offspring, it is conceivable that it will prevent transfer of these changes to the F2 generation.&nbsp / </p>
3

Premature aging of the lungs of the offspring induced by maternal nicotine exposure during gestation and lactation: protective effects of tomato juice

Mutemwa, Muyunda January 2012 (has links)
Philosophiae Doctor - PhD / exposed to nicotine through the blood and the milk of the mother. Nicotine is thus expected to interact with the developing fetus and the offspring of mothers who smoke or use NRT for smoking cessation, resulting in the interference with normal fetal and neonatal lung development. Maternal cigarette smoke or nicotine exposure produces adverse effects in the lungs of offspring, these include; intrauterine growth retardation, low birth weight, premature birth, reduced pulmonary function at birth, and a high occurrence of respiratory illnesses after birth. This study aimed at investigating the effects of maternal nicotine exposure during gestation and lactation on lung development in the offspring; to establish whether tomato juice can have protective effects on the fetal lung development and function in the offspring; and to determine if nicotine cases premature aging of the lungs of the offspring. It was therefore shown that maternal exposure to nicotine during gestation and lactation ad no significant effect on the growth parameters of the offspring. Maternal nicotine exposure during gestation and lactation had no effect on the growth parameters of the offspring, but resulted in compromised lung structure and function. The morphometric results demonstrated decrease in alveolar number, increase in alveolar size, and decrease in lung parenchyma of the nicotine exposed animals showing a gradual deterioration of the lung parenchyma. Structural alterations include emphysematous lesions, where the latter was accompanied by an increase in alveolar size (Lm), and a decrease in the tissue volume of the lung parenchyma. Thickening of alveolar walls was also evident and serves as an indication of remodeling of the extracellular matrix, also a characteristic of emphysema. A consequence of the gradual deterioration of the lung parenchyma is a decrease in the alveolar surface area available for gas exchange. The present study showed that the emphysematous lesions were conceivably a result of a reduced rate of cell proliferation accompanied by the increase in senescent cells numbers in the alveolar walls of the exposed offspring. The data of this study suggests that maternal nicotine exposure during gestation and lactation induces premature aging of the lungs of the offspring rendering the lungs of the offspring more susceptible to disease later in life. Since these structural changes occurred later in the life of the offspring and long after nicotine withdrawal, it is suggested that it is programmed during gestation and lactation. Smoking and NRT result in an increased load of oxidants in the mother and fetus. It also reduces the level of anti-oxidants and thereby compromising the ability of the mother to protect the fetus. It is hypothesized that this oxidant-antioxidant imbalance will program the lungs to age prematurely. The supplementation of the mother’s diet with tomato juice, rich in lycopene, other anti-oxidants such as vitamin C, as well as phytonutrients protected the lungs of the offspring against the adverse effects of maternal nicotine exposure. This supports the hypothesis mentioned above. The study further showed that the effects of grand-maternal nicotine exposure during gestation and lactation on the lungs of the F1 offspring is also transferred to the F2 offspring. This is most likely via the paternal and maternal germ line. Since tomato juice supplementation of the mother’s diet with tomato juice prevented the adverse effects of maternal nicotine exposure on the lungs of the offspring, it is conceivable that it will prevent transfer of these changes to the F2 generation. / South Africa
4

Vznik, přenos a ekologický význam apomixie v rodě Hieracium s.str.: role genetických a epigenetických mechanismů. / Origin, inheritance and ecological sygnificance of apomixis in the genus Hieracium s.str.: the role of genetic and epigenetic mechanims

Pinc, Jan January 2020 (has links)
Apomixis (asexual reproduction by seeds) has the considerable potential in agriculture and crop breeding due to its ability to produce genetically identical progenies in a form of persistent propagules, i.e. seeds. However, the processes laying behind the origin of apomixis and connected molecular mechanisms are still unknown. Despite the fact, that apomicts are considered to be an evolutionary dead-ends, they are often more widely distributed than their sexual relatives (this phenomenon is commonly referred to as geographical parthenogenesis (GP). Although this phenomenon is studied for decades, its causes are still not fully understood. Importantly, several recent studies pointed out that apomicts with limited genetic variability can at some extent react to changing environment through changes in gene transcription by epigenetic modifications. It is generally assumed, that hybridisation and polyploidization played a crucial role in the emergence of apomixis. For this reason, presented studies test the putative origin of selected polyploid apomicts and if the interspecific hybridisation between diploid sexuals triggers polyploidization using predominantly polyploid and apomictic genus Hieracium s. str. Surprisingly, the presented study demonstrates the hybrid origin of almost all investigated...

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