63 research outputs found
Cholesterol cholelithiasis in pregnant women: pathogenesis, prevention and treatment
Epidemiological and clinical studies have found that gallstone prevalence is twice as high in women as in men at all ages in every population studied. Hormonal changes occurring during pregnancy put women at higher risk. The incidence rates of biliary sludge (a precursor to gallstones) and gallstones are up to 30 and 12%, respectively, during pregnancy and postpartum, and 1-3% of pregnant women undergo cholecystectomy due to clinical symptoms or complications within the first year postpartum. Increased estrogen levels during pregnancy induce significant metabolic changes in the hepatobiliary system, including the formation of cholesterol-supersaturated bile and sluggish gallbladder motility, two factors enhancing cholelithogenesis. The therapeutic approaches are conservative during pregnancy because of the controversial frequency of biliary disorders. In the majority of pregnant women, biliary sludge and gallstones tend to dissolve spontaneously after parturition. In some situations, however, the conditions persist and require costly therapeutic interventions. When necessary, invasive procedures such as laparoscopic cholecystectomy are relatively well tolerated, preferably during the second trimester of pregnancy or postpartum. Although laparoscopic operation is recommended for its safety, the use of drugs such as ursodeoxycholic acid (UDCA) and the novel lipid-lowering compound, ezetimibe would also be considered. In this paper, we systematically review the incidence and natural history of pregnancy-related biliary sludge and gallstone formation and carefully discuss the molecular mechanisms underlying the lithogenic effect of estrogen on gallstone formation during pregnancy. We also summarize recent progress in the necessary strategies recommended for the prevention and the treatment of gallstones in pregnant women
Coordinated optimization of visual cortical maps (II) Numerical studies
It is an attractive hypothesis that the spatial structure of visual cortical
architecture can be explained by the coordinated optimization of multiple
visual cortical maps representing orientation preference (OP), ocular dominance
(OD), spatial frequency, or direction preference. In part (I) of this study we
defined a class of analytically tractable coordinated optimization models and
solved representative examples in which a spatially complex organization of the
orientation preference map is induced by inter-map interactions. We found that
attractor solutions near symmetry breaking threshold predict a highly ordered
map layout and require a substantial OD bias for OP pinwheel stabilization.
Here we examine in numerical simulations whether such models exhibit
biologically more realistic spatially irregular solutions at a finite distance
from threshold and when transients towards attractor states are considered. We
also examine whether model behavior qualitatively changes when the spatial
periodicities of the two maps are detuned and when considering more than 2
feature dimensions. Our numerical results support the view that neither minimal
energy states nor intermediate transient states of our coordinated optimization
models successfully explain the spatially irregular architecture of the visual
cortex. We discuss several alternative scenarios and additional factors that
may improve the agreement between model solutions and biological observations.Comment: 55 pages, 11 figures. arXiv admin note: substantial text overlap with
arXiv:1102.335
Prognostic implications of immunohistochemically detected YKL-40 expression in breast cancer
BACKGROUND: YKL-40 has been implicated as a mediator of collagen synthesis and extracellular matrix re-modeling as well as mitogenesis. Elevated serum levels of YKL-40 have been associated with worse survival in a variety of malignancies including breast cancer. We wished to determine if immunohistochemically detected expression had prognostic implications in breast cancer. METHODS: A prospectively collected database of breast cancer patients treated at the University Hospital of Newark was used for analysis. Immunohistochemistry was performed on archived tumor tissue from 109 patients for whom full clinical information and follow up was available. RESULTS: YKL-40 expression was noted in 37 patients (34%). YKL-40 immunoreactivity significantly correlated with larger tumor size, poorer tumor differentiation, and a greater likelihood of being estrogen and/or progesterone receptor negative. No significant correlation was demonstrated between YKL-40 status and nodal stage. At a mean follow up of 3.2 years, disease-free survival was significantly worse in the subset of patients whose tumors demonstrated YKL-40 expression compared to the non-expressors. In multivariate analysis, YKL-40 status was independent of T-stage and N-stage in predicting disease recurrence. CONCLUSION: Immunoreactivity for YKL-40 was a significant predictor of breast cancer relapse in this subset of patients. This was independent of T or N-stage and suggests that tumor immunohistochemistry for this protein may be a valuable prognostic marker in breast cancer
The Effect of Fluid Intake Following Dehydration on Subsequent Athletic and Cognitive Performance: a Systematic Review and Meta-analysis
Does carbon dioxide pneumoperitoneum enhance wound metastases following laparoscopic abdominal tumor surgery? A meta-analysis of 20 randomized control studies
Retinoblastoma tumor suppressor pathway in breast cancer: prognosis, precision medicine, and therapeutic interventions
Advanced squamous lung cancer: therapeutic options, future directions, unmet needs and results of a monocentric survey
Gene expression profile testing for breast cancer and the use of chemotherapy, serious adverse effects, and costs of care
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