Sulfide Catabolism Ameliorates Hypoxic Brain Injury

The mammalian brain is highly vulnerable to oxygen deprivation, yet the mechanism underlying the brain’s sensitivity to hypoxia is incompletely understood. Hypoxia induces accumulation of hydrogen sulfide, a gas that inhibits mitochondrial respiration. Here, we show that, in mice, rats, and naturally hypoxia-tolerant ground squirrels, the sensitivity of the brain to hypoxia is inversely related to the levels of sulfide:quinone oxidoreductase (SQOR) and the capacity to catabolize sulfide. Silencing SQOR increased the sensitivity of the brain to hypoxia, whereas neuron-specific SQOR expression prevented hypoxia-induced sulfide accumulation, bioenergetic failure, and ischemic brain injury. Excluding SQOR from mitochondria increased sensitivity to hypoxia not only in the brain but also in heart and liver. Pharmacological scavenging of sulfide maintained mitochondrial respiration in hypoxic neurons and made mice resistant to hypoxia. These results illuminate the critical role of sulfide catabolism in energy homeostasis during hypoxia and identify a therapeutic target for ischemic brain injury

Optimal Feedback Control for Anthropomorphic Manipulators

We study target reaching tasks of redundant anthropomorphic manipulators under the premise of minimal energy consumption and compliance during motion. We formulate this motor control problem in the framework of Optimal Feedback Control (OFC) by introducing a specific cost function that accounts for the physical constraints of the controlled plant. Using an approximative computational optimal control method we can optimally control a high-dimensional anthropomorphic robot without having to specify an explicit inverse kinematics, inverse dynamics or feedback control law. We highlight the benefits of this biologically plausible motor control strategy over traditional (open loop) optimal controllers: The presented approach proves to be significantly more energy efficient and compliant, while being accurate with respect to the task at hand. These properties are crucial for the control of mobile anthropomorphic robots, that are designed to interact safely in a human environment. To the best of our knowledge this is the first OFC implementation on a high-dimensional (redundant) manipulator

Comparative outcomes between palliative ileostomy and colostomy in patients with malignant large bowel obstruction

Objectives: Palliative stoma creation should be considered in patients at high risk of colonic metallic stent failure. However, it is unclear whether ileostomy or colostomy is superior. This study compared short-term outcomes between palliative ileostomy and colostomy. Methods: We identified 82 patients with malignant large bowel obstruction, caused by various advanced cancers, between January 2005 and December 2016. We compared short-term outcomes between the ileostomy group (n = 33) and the colostomy group (n = 49). Results: For all 82 patients, clinical success was achieved. Three patients with ileostomy died within 30 days of ostomy formation. The ileostomy group had statistically significant differences in median operative time (113 vs. 129 minutes, p = 0.045) and blood loss (8 vs. 40 g, p = 0.037) in comparison with the colostomy group. No statistically significant differences were observed in the surgical complications (30.3 vs. 38.8%, p = 0.431), in the median period to oral intake (3 vs. 4 days, p = 0.335) and in the hospital stay after surgery (32 vs. 27 days, p = 0.509) between the two groups. Overall stoma-related complications occurred in 27 (32.9%) patients. Stoma-related complications occurred more frequently in the ileostomy group (16/33 vs. 11/49 patients, p = 0.014). High output stoma (6 patients) and irritation (5 patients) occurred more frequently in the ileostomy group. Conclusions: Palliative colostomy is superior to ileostomy due to fewer stoma-related complications. When ileostomy is required, aggressive interventions for high output stomas should be implemented