The SQUAD Method for the Qualitative Modeling of Regulatory Networks.

The wealth of molecular information provided by high-throughput technologies has enhanced the efforts dedicated to the reconstruction of regulatory networks in diverse biological systems. This information, however, has proven to be insufficient for the construction of quantitative models due to the absence of sufficiently accurate measurements of kinetic constants. As a result, there have been efforts to develop methodologies that permit the use of qualitative information about patterns of expression to infer the regulatory networks that generate such patterns. One of these approaches is the SQUAD method, which approximates a Boolean network with the use of a set of ordinary differential equations. The main benefit of the SQUAD method over purely Boolean approaches is the possibility of evaluating the effect of continuous external signals, which are pervasive in biological phenomena. A brief description and code on how to implement this method can be found at the following link: https://github.com/caramirezal/SQUADBookChapter .

Thirty-Day Mortality After Lobectomy in Elderly Patients Eligible for Lung Cancer Screening.

BACKGROUND: Whether US surgeons have been able to replicate the low mortality rate of 1% after lobectomy experienced by patients treated in the National Lung Screening Trial is unknown. METHODS: To determine current operative 30-day mortality rates after lobectomy, we analyzed American College of Surgeons National Surgical Quality Improvement Program data files from 2005 to 2012. RESULTS: Of the 2,690 patients analyzed, 1,595 underwent open thoracotomy lobectomy and 1,095 underwent video-assisted thoracoscopic lobectomy. Sixty-three postoperative deaths occurred among the 2,690 patients (2.34% overall). The mortality rate for open lobectomy was 3.13% (50 cases) and that for video-assisted thoracoscopic lobectomy was 1.19% (13 cases [odds ratio 2.69, 95% confidence interval: 1.43 to 5.43, p < 0.05). Evaluation of mortality rates between surgical approaches (open versus video-assisted thoracoscopic) was performed by age group: group 1, aged 65 to 69 years (odds ratio 2.72, 95% confidence interval: 1 to 9.4, p < 0.05); group 2, aged 70 to 74 years (odds ratio 4.41, 95% confidence interval: 1.28 to 23.4, p < 0.05); and group 3, aged 75 to 80 years (no difference was found in group 3, p = 0.45). CONCLUSIONS: Among the hospitals participating in the American College of Surgeons National Surgical Quality Improvement Program, operative mortality rates after lobectomy are comparable to the operative mortality rates in the National Lung Screening Trial.