Annals of the New York Academy of Sciences
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Ann. N. Y. Acad. Sci. · Apr 2008
ReviewEndometriosis and infertility: epidemiology and evidence-based treatments.
Endometriosis is an estrogen-dependent disorder defined as the presence of endometrial tissue outside of the uterine cavity. A leading cause of infertility, endometriosis has a prevalence of 0.5-5% in fertile and 25-40% in infertile women. The optimal choice of management for endometriosis-associated infertility remains obscure. ⋯ Controlled ovarian hyperstimulation with intrauterine insemination is recommended in early-stage and surgically corrected endometriosis when pelvic anatomy is normal. In advanced cases, in vitro fertilization is a treatment of choice, and its success may be augmented with prolonged gonadotropin-releasing hormone analog treatment. Further randomized clinical trials focusing on diverse etiopathogenic mechanisms and therapeutic innovation are necessary to find more conclusive, evidence-based answers regarding this enigmatic disease.
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Ann. N. Y. Acad. Sci. · Mar 2008
ReviewThe brain's default network: anatomy, function, and relevance to disease.
Thirty years of brain imaging research has converged to define the brain's default network-a novel and only recently appreciated brain system that participates in internal modes of cognition. Here we synthesize past observations to provide strong evidence that the default network is a specific, anatomically defined brain system preferentially active when individuals are not focused on the external environment. Analysis of connectional anatomy in the monkey supports the presence of an interconnected brain system. ⋯ These two subsystems converge on important nodes of integration including the posterior cingulate cortex. The implications of these functional and anatomical observations are discussed in relation to possible adaptive roles of the default network for using past experiences to plan for the future, navigate social interactions, and maximize the utility of moments when we are not otherwise engaged by the external world. We conclude by discussing the relevance of the default network for understanding mental disorders including autism, schizophrenia, and Alzheimer's disease.
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The assessment of residual brain function in the vegetative state, is extremely difficult and depends frequently on subjective interpretations of observed spontaneous and volitional behaviors. For those patients who retain peripheral motor function, rigorous behavioral assessment supported by structural imaging and electrophysiology is usually sufficient to establish a patient's level of wakefulness and awareness. However, it is becoming increasingly apparent that, in some patients, damage to the peripheral motor system may prevent overt responses to command, even though the cognitive ability to perceive and understand such commands may remain intact. Advances in functional neuroimaging suggest a novel solution to this problem; in several recent cases, so-called "activation" studies have been used to identify residual cognitive function and even conscious awareness in patients who are assumed to be vegetative, yet retain cognitive abilities that have evaded detection using standard clinical methods.
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Ann. N. Y. Acad. Sci. · Jan 2008
Structural factors influencing the efficacy of neuromuscular transmission.
Neuromuscular junctions (NMJs) in different species share many features of structure and function. At the same time, important differences distinguish, for example, human NMJs from those in other species. An understanding of the biological context of the human NMJ helps in the interpretation of the effects of disease on the biophysical properties of neuromuscular transmission. ⋯ A genetic influence on NMJ size has recently been discovered in some patients with limb-girdle myasthenia (LGM). Mutations of the gene encoding Dok-7, an essential component of the agrin-muscle-specific kinase pathway that controls postsynaptic differentiation at the mammalian NMJ, results in impaired transmission because the NMJs are abnormally small and have reduced folding but have a normal local density of normal acetylcholine receptors. This condition emphasizes the importance of structural features in achieving reliability of neuromuscular transmission.
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Lymphangioleiomyomatosis (LAM) is a rare, multisystem disease affecting primarily premenopausal women. The disease is characterized by cystic lung disease, at times leading to respiratory compromise, abdominal tumors (in particular, renal angiomyolipomas), and involvement of the axial lymphatics (e.g., adenopathy, lymphangioleiomyomas). Disease results from the proliferation of neoplastic cells (LAM cells), which, in many cases, have a smooth muscle cell phenotype, express melanoma antigens, and have mutations in one of the tuberous sclerosis complex genes (TSC1 or TSC2). ⋯ Lymphatic channels, expressing characteristic lymphatic endothelial cell markers, are found within the LAM lung nodules. LAM cells may also be localized within the walls of the axial lymphatics, and, in some cases, penetrate the wall and proliferate in the surrounding adipose tissue. Consistent with extensive lymphatic involvement in LAM, the serum concentration of VEGF-D, a lymphangiogenic factor, is higher in LAM patients than in healthy volunteers.