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Search Results: 1 - 10 of 412114 matches for " Christopher M. Adams "
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A successful pregnancy following SEM fine tuning of hormonal priming
Susan M Adams, Christopher R Murphy
BMC Pregnancy and Childbirth , 2001, DOI: 10.1186/1471-2393-1-3
Abstract: A 47 year old women was chosen for endometrial biopsy, histopathological dating and endometrial observation utilising SEM to determine the integrity of her secretory uterine epithelium because of her age and several previously failed attempts at frozen ET. Exogenous E2 and P4 supplementation was administered in modified doses according to the SEM result, in consecutive cycles until the epithelial response appeared satisfactory for potential implantation.This case study demonstrates the dramatic change in epithelial characteristics that can be achieved as a response to these altered doses of E2 and P4. The uterine morphology changed from a hypotrophic to a mature, receptive epithelium such that ET resulted in the birth of healthy twin boys.The comparison between the consecutive biopsies in direct response to the SEM analysis and tailored modification of E2 and P4 dose clearly demonstrates, in this case, the effectiveness of individual morphological monitoring to maximise the successful outcome of ET.Although the function of the uterus is to provide an environment for implantation and pregnancy, the molecular and morphological events that occur on a regular and cyclical basis to facilitate this are not well understood. These cyclical changes occur as a direct response to the hormones E2 and P4 and can be monitored on a daily basis in conjunction with uterine biopsy allowing morphological assessment of the uterine epithelium. Utilizing repeat biopsy and examination by SEM, these cyclical changes allow hormonal manipulation and direct observation of the known morphological characteristics to be used as predictors of uterine receptivity. In conjunction with these markers, the appearance of uterodomes (pinopods) [1] in the secretory epithelium has become the morphological marker of choice for assessing receptivity and these structures are best observed by SEM [2-4].Although dating, and therefore predicting, the state of the secretory epithelium in a 28 day cycle, or with
Manipulation of the follicular phase: Uterodomes and pregnancy - is there a correlation?
Susan M Adams, Nalini Gayer, Vera Terry, Christopher R Murphy
BMC Pregnancy and Childbirth , 2001, DOI: 10.1186/1471-2393-1-2
Abstract: Seven pregnancies resulted in seven viable births including one twins and one miscarriage. Analysis of the individual regimes showed 5 days of P treatment to have a higher correlation for uterodomes in all 3 cycles observed individually. It was also observed that all 7 women demonstrated the appearance of uterodomes in at least one of their cycles.We conclude that manipulation of the follicular phase by shortening the period of E exposure to 7 days, does not compromise uterine epithelial morphology and we add weight to the conclusion that uterodomes indicate a receptive endometrium for implantation.Uterodomes are apical cellular protrusions which occur during the "nidation window" and have been used as uterine markers in conjunction with biopsy and scanning electron microscopy to determine the timing of implantation [1,2,3,4,5,6,7,8]. In some animals true pinocytotic structures have been demonstrated but in other animals including humans, the function of these structures, which somewhat resemble pinopods, is unknown. Hence [9] has suggested that these structures be referred to as uterodomes. Regardless of the function of uterodomes they are, however, a useful indicator of uterine receptivity in many studies including humans.The correlation between uterodome appearance and the nidation window first proposed by Psychoyos [10; 11], is now generally accepted. However there are still some mammals including humans where the presence and therefore function of uterodomes is not understood. This current work is part of ongoing worldwide interest in the cellular plasma membrane transformation to define the reason for the appearance of these structures [9; 12].Typically in IVF programs for frozen-thawed embryo transfer (ET) in women with normally functioning ovaries or in women receiving oocyte donation, the endometrium is prepared with exogenous hormones in a manner imitating that of the natural cycle in preparation for ET. Although several protocols for uterine preparation e
Fear of Violence, Family Support, and Well-Being among Urban Adolescents  [PDF]
Allyson M. Drinkard, Christopher G. Schell, Richard Adams
Open Journal of Social Sciences (JSS) , 2019, DOI: 10.4236/jss.2019.79008
Abstract: Our study examines how the fear of violence and family support influence adolescent social, psychological, and physical well-being, after controlling for exposure to violence and a range of demographic factors. We conduct a secondary analysis of the Project on Human Development in Chicago Neighborhoods (PHDCN) data (N = 1337) using mixed-effect, multi-level regression models for the total sample and for males only and females only samples. We find that family support is the most robust, main effects predictor in all three models and across all outcomes. Our analyses show that the fear of violence is associated with increases in social problems (especially for boys) and with decreases in self-rated health. We discuss the results and implications in light of sociological theories on the health and well-being of adolescents.
Acute liver failure following levetiracetam therapy for seizure prophylaxis in traumatic brain injury  [PDF]
Aasim Ali Syed, Christopher D. Adams
Case Reports in Clinical Medicine (CRCM) , 2012, DOI: 10.4236/crcm.2012.12010
Abstract: This case report investigates an uncommon occurrence of drug induced acute liver injury directly associated with the administration of levetiracetam in a patient following traumatic brain injury.
Determination of the Molecular Basis for a Limited Dimorphism, N417K, in the Plasmodium vivax Duffy-Binding Protein
Amy M. McHenry,Samantha J. Barnes,Francis B. Ntumngia,Christopher L. King,John H. Adams
PLOS ONE , 2012, DOI: 10.1371/journal.pone.0020192
Abstract: Invasion of human red blood cells by Plasmodium merozoites is vital for replication and survival of the parasite and, as such, is an attractive target for therapeutic intervention. Merozoite invasion is mediated by specific interactions between parasite ligands and host erythrocyte receptors. The P. vivax Duffy-binding protein (PvDBP) is heavily dependent on the interaction with the human Duffy blood group antigen/receptor for chemokines (DARC) for invasion. Region II of PvDBP contains many allelic polymorphisms likely to have arisen by host immune selection. Successful vaccine development necessitates a deeper understanding of the role of these polymorphisms in both parasite function and evasion of host immunity. A 3D structure of the homologous P. knowlesi DBP predicts that most variant residues are surface-exposed, including N417K, which is a dimorphic residue change that has previously been shown to be part of a linked haplotype that alters DBP sensitivity to inhibitory antibody. In natural isolates only two residues are found at this site, asparagine (N) and lysine (K). Site-directed mutagenesis of residue 417 was used to create a panel of 20 amino acid variants that were then examined for their binding phenotype and response to immune sera. Our results suggest that the observed dimorphism likely arose due to both structural requirements and immune selection pressure. To our knowledge, this is the first exhaustive examination of this kind of the role of a single amino acid residue in antigenic character and binding ability. Our results demonstrate that a single amino acid substitution can dramatically alter both the ability of the PvDBP to bind to human erythrocytes and its antigenic character.
Activation of CD40 with Platelet Derived CD154 Promotes Reactive Oxygen Species Dependent Death of Human Hepatocytes during Hypoxia and Reoxygenation
Ricky H. Bhogal, Christopher J. Weston, Stuart M. Curbishley, David H. Adams, Simon C. Afford
PLOS ONE , 2012, DOI: 10.1371/journal.pone.0030867
Abstract: Background Hypoxia and hypoxia-reoxygenation (H-R) are pathogenic factors in many liver diseases that lead to hepatocyte death as a result of reactive oxygen species (ROS) accumulation. The tumor necrosis factor super-family member CD154 can also induce hepatocyte apoptosis via activation of its receptor CD40 and induction of autocrine/paracrine Fas Ligand/CD178 but the relationship between CD40 activation, ROS generation and apoptosis is poorly understood. We hypothesised that CD40 activation and ROS accumulation act synergistically to drive human hepatocyte apoptosis. Methods Human hepatocytes were isolated from liver tissue and exposed to an in vitro model of hypoxia and H-R in the presence or absence of CD154 and/or various inhibitors. Hepatocyte ROS production, apoptosis and necrosis were determined by labelling cells with 2′,7′-dichlorofluorescin, Annexin-V and 7-AAD respectively in a three-colour reporter flow cytometry assay. Results Exposure of human hepatocytes to recombinant CD154 or platelet-derived soluble CD154 augments ROS accumulation during H-R resulting in NADPH oxidase-dependent apoptosis and necrosis. The inhibition of c-Jun N-terminal Kinase and p38 attenuated CD154-mediated apoptosis but not necrosis. Conclusions CD154-mediated apoptosis of hepatocytes involves ROS generation that is amplified during hypoxia-reoxygenation. This finding provides a molecular mechanism to explain the role of platelets in hepatocyte death during ischemia-reperfusion injury.
Endometrial response to IVF hormonal manipulation: Comparative analysis of menopausal, down regulated and natural cycles
Susan M Adams, Vera Terry, Margot J Hosie, Nalini Gayer, Christopher R Murphy
Reproductive Biology and Endocrinology , 2004, DOI: 10.1186/1477-7827-2-21
Abstract: Endometrial biopsies from 3 cohorts of patients were compared. The tissue samples taken from these patients were categorized into 8 different groups according to their baseline and the hormone regime used.Pre-treatment natural cycle tissue was variable in appearance. Downregulation with a GnRH analogue tissue appeared menopausal in character. HRT after downregulation resulted in tissue uniformity. HRT in menopause resulted in a 'lush' epithelial surface. HST in the natural cycle improved the morphology with significant difference in secretion between the two regimes examined.Down regulation plus HRT standardized surface appearance but tissue response is significantly different from the natural cycle, natural cycle plus HRT or menopause plus HRT. HRT in menopause reinstates tissue to a state similar to a natural cycle but significantly different from a natural cycle plus HST. HST with a natural cycle is similar to tissue from the natural cycle but significant differences reflect the influence of the particular hormones present (at any point) within the cycle.Successful reproduction in any species relies on a large number of interactions occurring at molecular, biochemical and morphological levels in the uterus. Changes in the uterine epithelium in preparation for implantation are characterised by a proliferation of cells, their differentiation, and alterations to the topography and composition of the apical plasma membrane in particular. Cells reach their maximum growth and sensitivity to the blastocyst at the time of implantation. This period of maximum sensitivity is referred to as the receptive phase and has a limited duration or window of time – the 'nidation window'. Uteri outside this phase of receptivity not only resist attachment by the blastocyst [1,2] but in many species are actively embryotoxic [3]. Thus, the uterus can be thought of as a primarily hostile environment where successful implantation and pregnancy are reliant on the precise co-ordination of e
Lost Terranes of Zealandia: possible development of late Paleozoic and early Mesozoic sedimentary basins at the southwest Pacific margin of Gondwanaland, and their destination as terranes in southern South America
Adams,Christopher J;
Andean geology , 2010,
Abstract: latest precambrian to ordovician metasedimentary successions and cambrian-ordovician and devonian-carboniferous granitoids form the major part of the basement of southern zealandia and adjacent sectors of antarctica and southeast australia. uplift/cooling ages of these rocks, and local devonian shallow-water cover sequences suggest that final consolidation of the basement occurred through late paleozoic time. a necessary consequence of this process would have been contemporaneous erosion and the substantial development of marine sedimentary basins at the pacific margin of zealandia. these are found nowhere at the present day, suggesting that the basins have been lost by tectonic erosion, perhaps in a margin-parallel dextral translation similar to late paleozoic-mesozoic suspect terranes of new zealand. aprobable detrital zircon age pattern is assembled for these lost zealandia sediments, and then compared with those of pre-jurassic (probable triassic to devonian) metasedimentary rocks in the chilean archipelago. significant mesoproterozoic, latest neoproterozoic-cambrian and devonian-carboniferous detrital zircon age components are common to both, thus supporting a possible chilean terrane destination for these 'lost terranes of zealandia'.
Lost Terranes of Zealandia: possible development of late Paleozoic and early Mesozoic sedimentary basins at the southwest Pacific margin of Gondwanaland, and their destination as terranes in southern South America Terrenos perdidos de Zealandia: posible desarrollo de cuencas sedimentarias del Paleozoico tardío y Mesozoico temprano en el margen suroccidental del Pacífico de Gondwana y su destino como terrenos en el sur de América del Sur
Christopher J Adams
Andean Geology , 2010,
Abstract: Latest Precambrian to Ordovician metasedimentary successions and Cambrian-Ordovician and Devonian-Carboniferous granitoids form the major part of the basement of southern Zealandia and adjacent sectors of Antarctica and southeast Australia. Uplift/cooling ages of these rocks, and local Devonian shallow-water cover sequences suggest that final consolidation of the basement occurred through Late Paleozoic time. A necessary consequence of this process would have been contemporaneous erosion and the substantial development of marine sedimentary basins at the Pacific margin of Zealandia. These are found nowhere at the present day, suggesting that the basins have been lost by tectonic erosion, perhaps in a margin-parallel dextral translation similar to late Paleozoic-Mesozoic suspect terranes of New Zealand. Aprobable detrital zircon age pattern is assembled for these lost Zealandia sediments, and then compared with those of pre-Jurassic (probable Triassic to Devonian) metasedimentary rocks in the Chilean archipelago. Significant Mesoproterozoic, latest Neoproterozoic-Cambrian and Devonian-Carboniferous detrital zircon age components are common to both, thus supporting a possible Chilean terrane destination for these 'lost terranes of Zealandia'. Las sucesiones metasedimentarias del Precámbrico tardío al Ordovícico y granitoides del Cámbrico-Ordovícico y Devónico-Carbonífero constituyen la mayor parte del basamento del sur de Zealandia y sectores adyacentes de la Antartica y el sudeste de Australia. Las edades de enfriamiento/alzamiento de estas rocas y la cobertura local de secuencias de aguas someras del Devónico, sugieren que la consolidación definitiva del basamento se produjo durante el Paleozoico tardío. Una consecuencia necesaria de este proceso habría sido la erosion contemporánea y el desarrollo sustancial de cuencas sedimentarias marinas en el margen del Pacífico de Zealandia. Estas no se encuentran en ninguna parte en la actualidad, lo que sugiere que las cuencas se han perdido por erosion tectónica, tal vez en una traslación dextral paralela al margen similar a los terrenos del Paleozoico tardío-Mesozoico de Nueva Zelanda. Hay una agrupación que da un probable patrón de edad de circones detríticos para estos sedimentos de la perdida Zealandia, comparables con aquellos de rocas metasedimentarias del pre-Jurásico (probable Triásico a Devónico) del archipiélago chileno. Importantes componentes de edades de circones detríticos del Mesoproterozoicos, Neoproterozoico tardío-Cámbrico y Devónico-Carbonífero son comunes a ambas regiones, favoreciendo así u
Strain Analysis of a Chiral Smectic A Elastomer
Christopher M. Spillmann,John H. Konnert,James M. Adams,Jeffrey R. Deschamps,Jawad Naciri,Banahalli R. Ratna
Physics , 2010, DOI: 10.1103/PhysRevE.82.031705
Abstract: We present a detailed analysis of the molecular packing of a strained liquid crystal elastomer composed of chiral mesogens in the smectic A phase. X-ray diffraction patterns of the elastomer collected over a range of orientations with respect to the X-ray beam were used to reconstruct the three-dimensional scattering intensity as a function of tensile strain. For the first time, we show that the smectic domain order is preserved in these strained elastomers. Changes in the intensity within a given scattering plane are due to reorientation, and not loss, of the molecular order in directions orthogonal to the applied strain. Incorporating the physical parameters of the elastomer, a nonlinear elastic model is presented to describe the rotation of the smectic-layered domains under strain, thus providing a fundamental analysis to the mechanical response of these unique materials.
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