Journal of investigative medicine : the official publication of the American Federation for Clinical Research
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Despite the clinical regression that typifies the initial response of advanced prostate cancer to gonadal testosterone depletion, tumors eventually progress. However, evidence supports the concept that signaling via the androgen receptor (AR) is important in progression to castration-resistant prostate cancer (CRPC). Steroid hormones are synthesized from cholesterol in a series of tightly regulated steps involving the cleavage of carbon-carbon bonds, the introduction of functional groups derived from activated molecular oxygen, and the oxidation and reduction of carbon-carbon and carbon-oxygen bonds. ⋯ Finally, a number of mechanisms have been reported by which the AR is activated independent of ligand. Recent observations have suggested that AR forms with constitutive activity occur in CRPC, stimulating transcription without a requirement for ligand. This overview outlines a broad view of how the mechanisms by which the AR may be activated, whether by alternate pathways of androgen synthesis or the production of alternate forms of the AR, with an emphasis on what aspects must be accounted for when using model systems to explore the biology of human prostate cancer.
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Percutaneous dilatational tracheotomy (PDT) is a well-established procedure in intensive care medicine. Several reports confirm a low acute and long-term complication rate. However, dilatational tracheotomy is still often postponed even in patients that are under ventilator support for more than 2 weeks. We present a retrospective study analyzing the subjective long-term results after percutaneous tracheotomy performed at our medical intensive care unit between 2002 and 2008. ⋯ Percutaneous dilatational tracheotomy is an easily performed, cost-saving method for long-term ventilated patients with a low rate of acute and long-term complications even in old and multimorbid internal medicine patients.
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Pleural effusion is relatively common in pneumonia. Because traditional methods for its diagnosis are not always effective, there is a need for new biomarkers to make its differential diagnosis easier. ⋯ Determination of procalcitonin and CRP, in the pleural fluid and blood, does not seem to provide great value to the diagnosis of PAR. However, calculating the product of the total neutrophil count and the CRP may be useful in the diagnosis of these effusions because increased values have a high specificity and predictive values.