Browsing by Subject "Pregnancy"
Now showing 1 - 11 of 11
Results Per Page
Sort Options
Item Autoimmune processes in the placentas of neural tube defect-affected pregnancies(2013-05) Palacios, Ana Maria; Finnell, Richard H.Neural Tube Defects (NTDs) are a group of common congenital malformations that result from incomplete neural tube closure leading to abnormalities of the brain and/or spinal cord. Unfortunately, their etiology remains unknown, probably due to complex multifactorial interactions. The protective effect of dietary folates in preventing NTDs is well known, but this beneficial effect is limited to the 60 to 70% of cases; leaving 30% of the population without any known option for improving pregnancy outcomes. The mechanism by which folates rescue NTD-affected embryos is poorly understood, but the ability of folate supplementation to overcome a significant percentage of NTDs and the critical role of 5-methyltetrahydrofolate in the remethylation of homocysteine (Hcy) to methionine in the placenta suggests that folate binding and/or transport might play a critical role during development. We hypothesized that maternal autoantibodies (AB) targeting placental folate receptor alpha (FRα) are blocking the receptor and limiting the ability of the FRα to bind folates, reducing intraembryonic folate levels. Furthermore, we hypothesized that AB binding to other relevant proteins required for trophoblastic growth and placentation can be involved in activating pathologic inflammatory pathways that can result in suboptimal uptake of nutrients and contribute to an abnormal closure of the neural tube. We developed a high throughput ELISA to evaluate whether mothers experiencing pregnancies complicated with NTDs are more likely to have placental AB to FRα than are mothers experiencing normal pregnancies. We optimized and simplified a protocol for AB elution from placental tissues and determined whether these antibodies were blocking the FRα from binding with available folates. Although anti-FRα IgG antibodies were not associated to the blocking activity in this study, we found that the blocking activity was higher in the placentas from NTD-affected pregnancies compared to controls, that FRα IgM antibodies are most likely the type of antibody produced during gestation that is most relevant to the blocking activity and that it is unlikely that autoimmunity against other developmental proteins associated with NTDs is generating the NTDs.Item Dynamic Changes in Collagen Organization Modulate Cervical Remodeling During Pregnancy and Parturtion: New Insights and the Potential for Improved Clinical Tools to Combat Preterm Birth(2012-07-17) Akins, Meredith Lynne; Mahendroo, MalaPreterm birth affects approximately 500,000 infants in the Unites States alone and is the second highest cause of infant morbidity in this country. Obstetricians still do not have reliable tools to diagnose or treat women presenting with premature labor. Understanding mechanisms by which the cervix remodels during term and preterm pregnancy is critical to formulate better methods for detection and treatment of preterm birth. The focus of this study was to identify how cervical collagen is reorganized throughout pregnancy to allow the cervix to become compliant for parturition. Beginning early in pregnancy a reduction in cervical collagen cross-links as well as a decline in matricellular proteins contribute to the changing cervical extracellular matrix environment. These cumulative changes result in increased collagen fibril diameter, as well as a progressive increase in tissue distensibility and a decline in tissue stiffness. Changes in collagen morphology over pregnancy can be visualized via non-invasive second harmonic generation (SHG). Quantification of specific morphological features such as collagen fiber diameter or porosity reveal progressive changes that allow one to distinguish stages in pregnancy. In addition, analysis of SHG images from two preterm birth models as well as one postterm pregnancy model validate the ability to use quantitative morphological measurements to distinguish normal from abnormal cervical remodeling. These findings suggest SHG technology is a powerful tool that may have potential clinically to predict preterm birth. In closing these studies have identified early and progressive changes in processing and assembly of collagen fibrils as well as changes in other ECM components that likely contribute to the incremental change in cervical tensile strength required for birth. [Keywords: cervix, partition, preterm birth, cervical remodeling, cervical softening, collagen, collagen cross-linking, cervical imaging]Item Endogenous Betaretroviruses in the Ovine Uterus and Conceptus(2011-10-21) Black, Sarah GraceEndogenous retroviruses (ERVs) comprise a significant portion of the genome of all mammals and have been implicated in placental development in multiple species. The ovine genome contains approximately 27 copies of endogenous betaretroviruses (enJSRVs) that are related to the exogenous Jaagsiekte sheep retrovirus (JSRV), an oncogenic retrovirus tropic to the lung. The enJSRV loci are abundantly expressed in the female reproductive tract and the conceptus, and they are essential to conceptus development. Studies were conducted to determine: 1) the effect of exogenous progesterone administration on conceptus development after loss of enJSRV Env; 2) the specific enJSRV env expressed in the developing conceptus; and 3) if the uterus produces enJSRV viral particles that are capable of transducing the conceptus. Study One determined the effects of exogenous progesterone on development of the conceptus in which enJSRV Env was ablated. Despite rescuing conceptus survival, the conceptuses were morphologically fragile and had reduced binucleate cell (BNC) numbers. These results suggest that mononuclear trophectoderm cell (MTC) proliferation and differentiation is dependent on enJSRV Env, even in a uterine environment supported by exogenous progesterone. Study Two assessed the enJSRV loci transcribed in the ovine conceptus during elongation before (day 13) and after (day 18) onset of BNC differentiation. The most represented loci in both day 13 and day 18 conceptuses encoded truncated Env proteins that did not contain membrane-spanning domains. Conceptuses from both time points contained evidence of the transcription of full-length, biologically active enJSRV Env, as well as completely intact proviral loci with the ability to produce viral particles in vitro. Study Three utilized a transpecies embryo transfer experiment to determine if the intact enJSRVs loci could produce viral particles in vivo. The presence of enJSRV viral particles in the uterus was confirmed, as was their ability to transduce the conceptus. Collectively, these studies provide evidence of truncated Env proteins, intact biologically active Env proteins, and enJSRVs viral particles within the ovine uterus and conceptus that are necessary to stimulate proliferation and differentiation of MTCs even in a uterine environment supported by exogenous progesterone.Item Food habits and nutrition knowledge of obstetric patients in a city-county health unit(Texas Tech University, 1970-12) Armistead, AnnNot availableItem Husband Involvement During Pregnancy as it Relates to Marital Satisfaction(Texas Tech University, 1974-08) Koumalats, Nelda Jo PriceNot Available.Item Parents Talking About the Birds and the Bees With Their Elementary School Aged Children: A Naturalistic Study(2013-07-22) Reichel, LoriThis dissertation presents three separate studies exploring parents? perceptions and recommendations for communicating with their third, fourth, and fifth grade children about human sexuality. First, a systematic literature review is presented summarizing past qualitative studies completed in the United States focusing on parents with children aged 18 years and under. This review summarizes (1) demographic information of parents from past studies, (2) perceived communication barriers experienced by parents regarding sexuality communication, and (3) perceived communication facilitators experienced by parents regarding sexuality communication. Second, noting the lack of research within a specific population of parents in the United States, a naturalistic study of parents with children in the third, fourth, and fifth grade is presented. Utilizing an emergent design, one-on-one interviews were conducted with 20 parents living in a town in central Texas. By coding collected data, a thematic analysis was used to summarize emergent themes. Themes included techniques parents utilized to have parent-child conversations about sexuality and discussed topics. Although different techniques and topics were raised, parents showed overall inconsistency in experiences or past discussions. Third, using data from the same 20 interviews, themes emerged from parents regarding recommendations. These included the recommendations that a booklet with age appropriate information on sexuality topics be developed for parents and parent workshops or classes covering age appropriate sexuality knowledge as well as techniques to use in parent-child communication be offered. Schools were the recommended source for these resources. Parents also shared feedback on the newly released National Sexuality Education Standards. Comparing past parent-child conversations on sexuality topics to the NSES, certain topics were discussed yet inconsistency was shown. In addition, parents disagreed on specific standards including those pertaining to the functions of reproductive parts, reproduction, and same sex orientation. Implications of this study are that parental resources are needed to help parents communicate with their children about sexuality beginning at a young age. And, for those resources already existing, including workshops, books, and on-line sources, parents need to be made aware of their existence. In addition, future research is needed to explore if younger children are learning from parent-child conversations about sexuality.Item Perceptions of prenatal care in older adolescent Latinas(2014-05) Torres, Rosamar; Rew, Lynn; Brown, Adama; Garcia, Alexandria; Padilla, Yolanda; Walker, LorraineThe knowledge that initiation of prenatal care after the first trimester of pregnancy is associated with poor fetal and maternal outcomes has led to increased efforts to improve access to prenatal care in the U.S. Despite these efforts, Latinas continue to underutilize these services and enter care late. Pregnant adolescent Latinas are at increased risk for morbidity and mortality during pregnancy and labor, thereby increasing risks for mortality, blindness, deafness, mental retardation, and cerebral palsy in their the neonates. The current literature surrounding perceptions of prenatal care focuses on women overall without taking into account culture, ethnicity or age. Thus, little is known about adolescent Latinas’ perceptions of prenatal care and why they enter care late. Hence the purpose of this study was to critique the literature regarding Latinas and their perceptions of prenatal care; to determine the psychometric properties of The Perceptions of Prenatal Care Survey which was piloted in the Phase I of the dissertation; to identify perceptions of prenatal care in older adolescent Latinas utilizing the Access Barriers to Care Index and the Perceptions of Prenatal Care Survey in Phase II of the study; and to determine if relationships exist between variables in the conceptual model and participants’ adequacy of and timely entry into prenatal care. Phase I revealed the survey had good internal consistency (Cronbach’s alpha = 0.88) and validity (S-CVI =0.81). Phase II revealed that a majority (94.5%) of participants perceived that timely prenatal care as important; however, only 55.6% entered care on time. Over 70% of the sample had experienced personal and healthcare imposed barriers when accessing prenatal care. Social support from partners and friends was associated with adequate prenatal care; and having some college education was associated with timely prenatal care. Influence from healthcare workers did not have a statistically significant effect on timely or adequate prenatal care. Due to sampling issues and possible response bias, the study is limited. Future research on this topic calls for more stringent sampling measures that will take race, acculturation, nativity and immigration status into consideration.Item Pregnant and parenting female students' perspectives of school experiences: case studies(Texas Tech University, 2003-05) Perry, Kimberly BilbreyThe purpose of this study was to explore the past and present school experiences of pregnant and parenting female students to determine if these experiences influenced their decision to become pregnant and raise a child. Most research studies on the role of education for pregnant and parenting teens focus on program evaluation or critical analysis of the social "problem" of teenage pregnancy. Very little research exists on the self-perception of pregnant and parenting teens as students, including their academic history, successes, challenges and stmggles. This study was not to evaluate a particular system or program for educating pregnant and parenting adolescents, but rather to "give voice" to a unique and diverse population of female school students who are underrepresented in educational research.Item Teen pregnancy in Mexican American girls(2005-08) Aguero-Reyes, Zenaida Victoria; Caldera, Yvonne M.; Bell, Nancy J.; Reifman, AlanThe study explored Mexican-American adolescent girls’ feelings and thoughts about factors that contributed to teen pregnancy. Eight girls were recruited in West Texas city. The ages of the teens were 16-20. Brofenbrenner was used as a framework to classify the themes that emerged from the transcripts. The themes were organized under the microsystem and macrosystem. The results indicated that they did not plan on having a baby that it was an unplanned event. Although some parents did provide information regarding contraception, they still made the choice not to continue to take them. There is discussion on how her development of adolescence attributes to her unplanned pregnancy.Item Teen pregnancy in Mexican American girls(Texas Tech University, 2005-08) Aguero-Reyes, Zenaida Victoria; Caldera, Yvonne M.; Bell, Nancy J.; Reifman, AlanThe study explored Mexican-American adolescent girls’ feelings and thoughts about factors that contributed to teen pregnancy. Eight girls were recruited in West Texas city. The ages of the teens were 16-20. Brofenbrenner was used as a framework to classify the themes that emerged from the transcripts. The themes were organized under the microsystem and macrosystem. The results indicated that they did not plan on having a baby that it was an unplanned event. Although some parents did provide information regarding contraception, they still made the choice not to continue to take them. There is discussion on how her development of adolescence attributes to her unplanned pregnancy.Item Women’s psychology of disease avoidance(2009-12) Fleischman, Diana Santos; Buss, David M.The following will explore how physiological states influence measures of disease avoidance. The first two studies investigate the psychological effects of progesterone and immunomodulation to behaviors relevant to disease avoidance. In the first study, I investigated the effect of menstrual phase on disgust sensitivity and obsessive-compulsive disorder symptomology finding that in periods of high estimated progesterone women show increased disgust sensitivity and OCD symptomology. In the second study I used salivary assays to measure progesterone and correlate progesterone level with a variety of measures of disease avoidance. In the final study I investigated how sexual arousal, a motivational state that moves an organism closer to potential disease vectors and disgust, an emotion that motivates organisms away from disease vectors, mitigate one another using image ratings and an objective measure of physiological sexual arousal, vaginal photoplethysmography.