Noninvasive monitoring of murine tumor blood flow during and after photodynamic therapy provides early assessment of therapeutic efficacy.

PURPOSE: To monitor tumor blood flow noninvasively during photodynamic therapy (PDT) and to correlate flow responses with therapeutic efficacy. EXPERIMENTAL DESIGN: Diffuse correlation spectroscopy (DCS) was used to measure blood flow continuously in radiation-induced fibrosarcoma murine tumors during Photofrin (5 mg/kg)/PDT (75 mW/cm2, 135 J/cm2). Relative blood flow (rBF; i.e., normalized to preillumination values) was compared with tumor perfusion as determined by power Doppler ultrasound and was correlated with treatment durability, defined as the time of tumor growth to a volume of 400 mm3. Broadband diffuse reflectance spectroscopy concurrently quantified tumor hemoglobin oxygen saturation (SO2). RESULTS: DCS and power Doppler ultrasound measured similar flow decreases in animals treated with identical protocols. DCS measurement of rBF during PDT revealed a series of PDT-induced peaks and declines dominated by an initial steep increase (average +/- SE: 168.1 +/- 39.5%) and subsequent decrease (59.2 +/- 29.1%). The duration (interval time; range, 2.2-15.6 minutes) and slope (flow reduction rate; range, 4.4 -45.8% minute(-1)) of the decrease correlated significantly (P = 0.0001 and 0.0002, r2= 0.79 and 0.67, respectively) with treatment durability. A positive, significant (P = 0.016, r2= 0.50) association between interval time and time-to-400 mm3 was also detected in animals with depressed pre-PDT blood flow due to hydralazine administration. At 3 hours after PDT, rBF and SO2 were predictive (P < or = 0.015) of treatment durability. CONCLUSION: These data suggest a role for DCS in real-time monitoring of PDT vascular response as an indicator of treatment efficacy.     

Vitamin A Deficiency in Pregnancy: Perspectives after Bariatric Surgery

This study aims to describe the clinical consequences of vitamin A deficiency (VAD) in pregnant women after bariatric surgery. Included are studies on VAD during pregnancy and after bariatric surgery conducted in humans from 1993 to 2011. There are few investigations on the relationship between pregnancy and bariatric surgery and on the damage to the binomial mother–child resulting from VAD in this relationship. The high percentage of VAD in the postoperative period is a cause for concern, especially considering the function of this vitamin in certain biological moments and in moments of intense nutritional demand. This vitamin serum evaluation is recommended during the prenatal period.     

Towards Autonomous Creative Systems: A Computational Approach

This paper reviews the long-standing debate surrounding the nature of machine intelligence, autonomy and creativity and argues for an approach to developing autonomous computational creativity that models personal motivations, social interactions and the evolution of domains. The implications of this argument on the types of cognitive processes that are required for the development of autonomous computational creativity are explored and a possible approach to achieving the goal is described. In particular, this paper describes the development of artificial creative systems composed of intrinsically motivated agents engaging in language games to interact with a shared social and cultural environment. The paper discusses the implications that this type of approach may have for the development of autonomous creative systems.