ACR Appropriateness Criteria? chronic chest pain--high probability of coronary artery disease

Imaging is valuable in determining the presence, extent, and severity of myocardial ischemia and the severity of obstructive coronary lesions in patients with chronic chest pain in the setting of high probability of coronary artery disease. Imaging is critical for defining patients best suited for medical therapy or intervention, and findings can be used to predict long-term prognosis and the likely benefit from various therapeutic options. Chest radiography, radionuclide single photon-emission CT, radionuclide ventriculography, and conventional coronary angiography are the imaging modalities historically used in evaluating suspected chronic myocardial ischemia. Stress echocardiography, PET, cardiac MRI, and multidetector cardiac CT have all been more recently shown to be valuable in the evaluation of ischemic heart disease. Other imaging techniques may be helpful in those patients who do not present with signs classic for angina pectoris or in those patients who do not respond as expected to standard management. The ACR Appropriateness Criteria(?) are evidence-based guidelines for specific clinical conditions that are reviewed every 2 years by a multidisciplinary expert panel. The guideline development and review include an extensive analysis of current medical literature from peer-reviewed journals and the application of a well-established consensus methodology (modified Delphi) to rate the appropriateness of imaging and treatment procedures by the panel. In those instances in which evidence is lacking or not definitive, expert opinion may be used to recommend imaging or treatment.     

CYP450 activities before and after Roux-en-Y gastric bypass: correlation with their intestinal and liver content

BackgroundSeveral anatomic and physiologic changes occur after Roux-en-Y gastric bypass (RYGB) and its associated weight loss. At present, no single unified model can predict changes in drug metabolism associated with either RYGB surgery or weight loss.ObjectiveThe aim of this longitudinal human study was to measure the activity of the 5 most important Cytochrome P450 (CYP) involved in drug metabolism in patients with obesity before and after RYGB. Jejunal and liver biopsies obtained during bariatric surgery were used to measure CYP amount, and correlation between jejunal and hepatic content was estimated.SettingFrench university hospital.MethodsEleven volunteers with a mean body mass index of 44.1 (39.4–50.0) kg/m² participated in the study. CYP1 A2, CYP2 C9, CYP2 C19, CYP2 D6, and CYP3 A4/A5 activities were measured with a cocktail approach before surgery (visit 1), 5 to 8 weeks after surgery (visit 2), and 25 to 30 weeks after surgery (visit 3).ResultsCYP3 A4/A5 and CYP2 C9 metabolic ratios were transitorily and significantly increased immediately after surgery (visit 2 versus 1). RYGB procedure does not lead to significant change in CYP activity 25 to 30 weeks after surgery (visit 3 versus 1). Samples obtained during surgery showed significant correlation between intestinal and liver contents of CYP2 C9 and CYP3 A4/A5. Except for liver CYP1 A2 content, CYP metabolic activities were not correlated to their intestinal or liver contents.ConclusionsThis study showed that RYGB does not lead to a significant change in CYP activity 25 to 30 weeks after surgery. However, CYP3 A4/A5 and CYP2 C9 activities were transitorily and significantly increased in the immediate postoperative context (<1 mo), representing a situation at risk of reduced drug exposure for several drugs that have a narrow therapeutic window. In addition, considering high interindividual variability in liver contents and activity of CYP3 A4 and CYP2 C9, patients receiving drugs highly metabolized by these 2 CYPs should be closely monitored in the immediate postoperative period.     

Twice-weekly administration of kisspeptin-54 for 8 weeks stimulates release of reproductive hormones in women with hypothalamic amenorrhea

Kisspeptin is a novel therapeutic target for infertility. A single kisspeptin-54 (KP-54) injection acutely stimulates the release of reproductive hormones in women with hypothalamic amenorrhea (HA), a commonly occurring condition characterized by absence of menstruation; however, twice-daily administration of KP-54 results in tachyphylaxis. We determined the time course of desensitization to twice-daily KP-54 injections, compared the effects of twice-daily and twice-weekly administration regimens of KP-54, and studied the effects of long-term twice-weekly administration of KP-54 on the release of reproductive hormones in women with HA. When KP-54 was administered twice daily, responsiveness to luteinizing hormone (LH) diminished gradually, whereas responsiveness to follicle-stimulating hormone (FSH) was nearly abolished by day 2. Twice-weekly KP-54 administration resulted in only partial desensitization, in contrast to the complete tolerance achieved with twice-daily administration. Women with HA who were treated with twice-weekly KP-54 injections had significantly elevated levels of reproductive hormones after 8 weeks as compared with treatment with saline. No adverse effects were observed. This study provides novel pharmacological data on the effects of KP-54 on the release of reproductive hormones in women with HA.