916 resultados para Raffles, Hugh
Resumo:
BACKGROUND & AIMS: There is controversy over whether coagulation status predicts bleeding caused by ulceration after esophageal varices band ligation (EVL). METHODS: EVL was performed for primary (n = 45) or secondary (n = 105) prophylaxis in 150 patients with cirrhosis (Child A, n = 74, 49%; Child B, n = 42, 28%; Child C, n = 34, 23%). International normalized ratio (INR) and platelet counts were assessed in all. In 92 patients, levels of factor V, fibrinogen, D-dimer, protein C and protein S, von Willebrand factor, and thromboelastography (TEG) were assessed. Platelet count < 50 x 10(3)/mm(3) and INR > 1.5 were considered high-risk cutoff for bleeding. Conversely, platelet count >= 50 x 10(3)/mm(3) with INR <= 1.5 were safe cutoffs. RESULTS: Overall, 11 patients (7.3%) had post-EVL ulcer bleeding. Bleeding occurred in S patients with Child A/B (4.3%) and 6 patients with Child C (17%) (P = .0174 for Child A/B versus Child C). Eight patients with bleeding were among the 110 below the cutoff for INR and platelet count, whereas only 3 of the patients with bleeding were among the 40 patients with purported high-risk values (P = 1.0). Among the 92 patients with expanded coagulation tests, bleeding occurred in S. There was no difference in any of the coagulation parameters, including overall TEG patterns, between patients who did and did nor bleed. CONCLUSIONS: Post-EVL ulcer bleeding was associated with Child C status but not with conventional or expanded coagulation indices in cirrhotic patients without renal failure or infection undergoing elective EVL. These results call into question the common use of prophylactic procoagulants in the elective setting.
Resumo:
The human endometrium is a dynamic tissue that undergoes cycles of growth and regression with each menstrual cycle. Adult progenitor stem cells are likely responsible for this remarkable regenerative capacity; these same progenitor stem cells may also have an enhanced capacity to generate endometriosis if shed in a retrograde fashion. The progenitor stem cells reside in the uterus; however, less-committed mesenchymal stem cells may also travel from other tissues such as bone marrow to repopulate the progenitor population. Mesenchymal stem cells are also involved in the pathogenesis of endometriosis and may be the principle source of endometriosis outside of the peritoneal cavity when they differentiate into endometriosis in ectopic locations. Finally, besides progenitor stem cells, recent publications have identified multipotent stem cells in the endometrium. These multipotent stem cells are a readily available source of cells that are useful in tissue engineering and regenerative medicine. Endometrial stem cells have been used to generate chondrocytes, myocytes, neurons, and adiposites in vitro as well as to replace dopaminergic neurons in a murine model of Parkinson`s disease.
Calpain5 expression is decreased in endometriosis and regulated by HOXA10 in human endometrial cells
Resumo:
Calpains have been implicated in the regulation of apoptosis. Here, we identified Calpain5 as a target of HOXA10 transcriptional regulation in endometrial cells as well as its aberrant regulation in endometriosis. Histologically confirmed biopsies of endometriosis were obtained from 20 women. Eutopic endometrium was collected by endometrial biopsy from 30 controls and from the 20 subjects with endometriosis. First trimester decidual samples were obtained from five subjects at the time of pregnancy termination. Immunohistochemistry was used to identify Calpain5 expression. Calpain5 was expressed in endometrial stromal and glandular cells throughout the menstrual cycle and in decidua. Calpain5 protein expression was decreased in both stromal and glandular cells from women with endometriosis compared with that of fertile controls. Human endometrial stromal and epithelial cell lines were transfected with pcDNA/HOXA10, HOXA10 siRNA or respective controls. Quantitative real-time RT-PCR was performed to determine expression of HOXA10 and Calpain5 in each group. Transfection of HESC cells with an HOXA10 expression construct led to increased Calpain5 expression, whereas transfection with siRNA resulted in decreased expression. In conclusion, Calpain5 expression is regulated by HOXA10. Calpain5 expression was decreased in endometriosis likely as a result of decreased HOXA10 expression. Decreased apoptosis in endometrial cells may promote the development of endometriosis through a pathway involving HOXA10, Calpain5 and caspase.
Resumo:
The major proteins of baboon milk were identified as beta -lactoglobulin (beta LG), alpha -lactalbumin (alpha LA), lysozyme, lactoferrin, casein, and albumin by immobiline isoelectric focusing, SDS-PAGE, immunoblotting of gels with rabbit antisera to human alpha LA, lysozyme, and albumin and bovine beta LG and casein, and N-terminal sequencing of proteins blotted from gels. The first 30 N-terminal residues of baboon polymorphism at residue 2. The complete cDNA sequence and derived amino acid composition of beta LG were elucidated using RT-PCR amplification of poly(A)(+) mRNA purified from lactating mammary gland. Baboon beta LG identified to date. beta LG and alpha LA polymorphisms with three (A, B, and C) and two (A and B) variants, respectively, were detected by immobiline IEF, pH 4-6, of individual baboon milk samples at varying stages of lactation.
Resumo:
In this study we present a novel automated strategy for predicting infarct evolution, based on MR diffusion and perfusion images acquired in the acute stage of stroke. The validity of this methodology was tested on novel patient data including data acquired from an independent stroke clinic. Regions-of-interest (ROIs) defining the initial diffusion lesion and tissue with abnormal hemodynamic function as defined by the mean transit time (MTT) abnormality were automatically extracted from DWI/PI maps. Quantitative measures of cerebral blood flow (CBF) and volume (CBV) along with ratio measures defined relative to the contralateral hemisphere (r(a)CBF and r(a)CBV) were calculated for the MTT ROIs. A parametric normal classifier algorithm incorporating these measures was used to predict infarct growth. The mean r(a)CBF and r(a)CBV values for eventually infarcted MTT tissue were 0.70 +/-0.19 and 1.20 +/-0.36. For recovered tissue the mean values were 0.99 +/-0.25 and 1.87 +/-0.71, respectively. There was a significant difference between these two regions for both measures (P
Resumo:
A decision theory framework can be a powerful technique to derive optimal management decisions for endangered species. We built a spatially realistic stochastic metapopulation model for the Mount Lofty Ranges Southern Emu-wren (Stipiturus malachurus intermedius), a critically endangered Australian bird. Using diserete-time Markov,chains to describe the dynamics of a metapopulation and stochastic dynamic programming (SDP) to find optimal solutions, we evaluated the following different management decisions: enlarging existing patches, linking patches via corridors, and creating a new patch. This is the first application of SDP to optimal landscape reconstruction and one of the few times that landscape reconstruction dynamics have been integrated with population dynamics. SDP is a powerful tool that has advantages over standard Monte Carlo simulation methods because it can give the exact optimal strategy for every landscape configuration (combination of patch areas and presence of corridors) and pattern of metapopulation occupancy, as well as a trajectory of strategies. It is useful when a sequence of management actions can be performed over a given time horizon, as is the case for many endangered species recovery programs, where only fixed amounts of resources are available in each time step. However, it is generally limited by computational constraints to rather small networks of patches. The model shows that optimal metapopulation, management decisions depend greatly on the current state of the metapopulation,. and there is no strategy that is universally the best. The extinction probability over 30 yr for the optimal state-dependent management actions is 50-80% better than no management, whereas the best fixed state-independent sets of strategies are only 30% better than no management. This highlights the advantages of using a decision theory tool to investigate conservation strategies for metapopulations. It is clear from these results that the sequence of management actions is critical, and this can only be effectively derived from stochastic dynamic programming. The model illustrates the underlying difficulty in determining simple rules of thumb for the sequence of management actions for a metapopulation. This use of a decision theory framework extends the capacity of population viability analysis (PVA) to manage threatened species.
Resumo:
Using benthic habitat data from the Florida Keys (USA), we demonstrate how siting algorithms can help identify potential networks of marine reserves that comprehensively represent target habitat types. We applied a flexible optimization tool-simulated annealing-to represent a fixed proportion of different marine habitat types within a geographic area. We investigated the relative influence of spatial information, planning-unit size, detail of habitat classification, and magnitude of the overall conservation goal on the resulting network scenarios. With this method, we were able to identify many adequate reserve systems that met the conservation goals, e.g., representing at least 20% of each conservation target (i.e., habitat type) while fulfilling the overall aim of minimizing the system area and perimeter. One of the most useful types of information provided by this siting algorithm comes from an irreplaceability analysis, which is a count of the number of, times unique planning units were included in reserve system scenarios. This analysis indicated that many different combinations of sites produced networks that met the conservation goals. While individual 1-km(2) areas were fairly interchangeable, the irreplaceability analysis highlighted larger areas within the planning region that were chosen consistently to meet the goals incorporated into the algorithm. Additionally, we found that reserve systems designed with a high degree of spatial clustering tended to have considerably less perimeter and larger overall areas in reserve-a configuration that may be preferable particularly for sociopolitical reasons. This exercise illustrates the value of using the simulated annealing algorithm to help site marine reserves: the approach makes efficient use of;available resources, can be used interactively by conservation decision makers, and offers biologically suitable alternative networks from which an effective system of marine reserves can be crafted.