Normalization in quantitative [18F]FDG PET imaging: the 'body surface area' may be a volume

Non-invasive methods for quantifying [(18)F]FDG uptake in tumours often require normalization to either body weight or body surface area (BSA), as a surrogate for [(18)F]FDG distribution volume (DV). Whereas three dimensions are involved in DV and weight (assuming that weight is proportional to volume), only two dimensions are obviously involved in BSA. However, a fractal geometry interpretation, related to an allometric scaling, suggests that the so-called 'body surface area' may stand for DV.     

Influence of on-going treatment with angiotensin-converting enzyme inhibitor or angiotensin receptor blocker on the outcome of patients treated with intravenous rt-PA for ischemic stroke

Journal of Neurology - Many patients who receive intravenous (i.v.) recombinant tissue-plasminogen activator (rt-PA) for acute cerebral ischemia were under angiotensin-converting enzyme inhibitors...     

Prospective observational study of low thresholds for platelet transfusion in adult dengue patients

BACKGROUND: The practice of platelet (PLT) transfusions has been adopted into the standard clinical practice in many dengue‐endemic countries. Because many patients were found to have received unnecessary PLT transfusions, the development of guidelines for the management of dengue patients with thrombocytopenia has become a necessity. STUDY DESIGN AND METHODS: An emergency department–based prospective observational study was conducted in Martinique during a dengue outbreak in adult patients presenting with an acute febrile illness. Patients with severe bleeding and/or who underwent invasive intensive care procedures or emergency surgery were given PLT transfusion to achieve PLT counts of more than 50 × 10⁹/L. PLT transfusion was also considered for patients with PLT counts of less than 5 × 10⁹/L and for those with associated risk factors and PLT counts of less than 20 × 10⁹/L. RESULTS: A total of 350 patients were admitted with confirmed dengue infections. Most of them had secondary serotype‐2 infections. PLT counts of less than 50 × 10⁹/L were recorded in 165 patients (47.1%). PLT transfusion was administered to 9 patients with thrombocytopenia. The indications included severe bleeding (5 cases), invasive procedures (3 cases), emergency surgery (1 case), and/or associated risk factors (2 cases). The median time duration from the onset of fever to PLT transfusion was 6 days (range, 4‐10 days). The median amount of PLTs transfused was 3.66 × 10¹¹ (range, 2.8 × 10¹¹‐13.2 × 10¹¹). The median PLT yield was +12.4% (range, ?3.9% to +67.1%). Three patients died. All other patients recovered during the second week after the onset of fever. CONCLUSION: A restrictive strategy for PLT transfusion based on clinical features and low PLT count thresholds proved to be feasible and safe for adult dengue patients.     

Excitatory and inhibitory pain mechanisms during the menstrual cycle in healthy women

Sex differences in pain perception have been clearly documented in the literature during the last decades and it has been shown that women perceived more pain than men. Sex hormones (SHs) are thought to be one of the main mechanisms which explain sex differences in pain. Pain is a dynamic phenomenon involving both excitatory and inhibitory mechanisms. Previous studies have verified the effect of SH on excitatory mechanisms but not on endogenous pain inhibitory mechanisms. The main objective of this study was to establish if pain perception and diffuse noxious inhibitory control (DNIC) vary across the menstrual cycle (MC). Thirty-two healthy women with a regular MC were tested three times across their MC (days 1–3, days 12–14 and days 19–23). Experimental pain consisted of two tonic heat pain stimulations (thermode) separated by a 2-min cold pressor test (CPT) (conditioning stimulus activating DNIC). Pain ratings were measured with a visual analogue scale. Heat pain threshold, pain tolerance and mean pain intensity during both the 2-min thermode test and CPT did not vary throughout the MC. However, we found significantly more pain inhibition (DNIC effectiveness) during the ovulatory phase compared to the menstrual and luteal phases (p = 0.05). The main finding of this study is the observation that only inhibitory mechanisms (DNIC analgesia) and not excitatory pain mechanisms vary throughout the MC, where women have greater DNIC in the ovulatory phase. The higher occurrence of pain and lower pain threshold previously reported during the MC could be related to a reduction in endogenous pain control mechanisms.