Visceral Obesity Promotes Lung Cancer Progression-Toward Resolution of the Obesity Paradox in Lung Cancer.

INTRODUCTION: Although obesity is associated with adverse cancer outcomes in general, most retrospective clinical studies suggest a beneficial effect of obesity in NSCLC. METHODS: Hypothesizing that this "obesity paradox" arises partly from the limitations of using body mass index (BMI) to measure obesity, we quantified adiposity using preoperative computed tomography images. This allowed the specific determination of central obesity as abdominal visceral fat area normalized to total fat area (visceral fat index [VFI]). In addition, owing to the previously reported salutary effect of metformin on high-BMI patients with lung cancer, metformin users were excluded. We then explored associations between visceral obesity and outcomes after surgical resection of stage I and II NSCLC. We also explored potential immunologic underpinnings of such association using complimentary analyses of tumor gene expression data from NSCLC tumors and the tumor transcriptome and immune microenvironment in an immunocompetent model of lung cancer with diet-induced obesity. RESULTS: We found that in 513 patients with stage I and II NSCLC undergoing lobectomy, a high VFI is associated with decreased recurrence-free and overall survival. VFI was also inversely related to an inflammatory transcriptomic signature in NSCLC tumors, consistent with observations made in immunocompetent murine models wherein diet-induced obesity promoted cancer progression while exacerbating elements of immune suppression in the tumor niche. CONCLUSIONS: In all, this study uses multiple lines of evidence to reveal the adverse effects of visceral obesity in patients with NSCLC, which align with those found in animal models. Thus, the obesity paradox may, at least in part, be secondary to the use of BMI as a measure of obesity and the confounding effects of metformin use.

A Sustainable Model For Delivering High-Quality, Efficient Cataract Surgery In Southern India.

Cataracts are a leading cause of reversible blindness in India, where millions of people can be effectively treated for this condition with surgery. The Aravind Eye Care System in southern India developed an efficient system for delivering high-quality and low-cost cataract surgery. We provide a detailed accounting of costs of cataract surgery at the system and a cost-utility analysis. Total costs per operation were US$120, or $195 per quality-adjusted life-year gained. Using these data and population-based estimates of cataract prevalence, we calculate that eliminating cataract-related blindness and low vision in India would cost $2.6 billion and would yield a net societal benefit of $13.5 billion. Factors contributing to the highly cost-effective care at the Aravind Eye Care System include the domestic manufacturing of supplies, the use of a specialized workforce and standardized protocols, and the presence of few regulatory hurdles. Lessons learned from the system can help improve the delivery of cataract surgery and other ambulatory care surgeries in India and abroad.

Nucleus management with irrigating vectis.

The main objective in modern cataract surgery is to achieve a better unaided visual acuity with rapid post-surgical recovery and minimal surgery-related complications. Early visual rehabilitation and better unaided vision can be achieved only by reducing the incision size. In manual small incision cataract surgery (MSICS), incision is between 5.5 to 7 mm. Once the nucleus is prolapsed into the anterior chamber, it can be extracted through the tunnel. Nucleus extraction with an irrigating vectis is a very simple technique, which combines mechanical and hydrostatic forces to express out the nucleus. This technique is time-tested with good results and more than 95% of nuclei in MSICS are extracted in this way offering all the merits of phacoemulsification with the added benefits of having wider applicability, better safety, shorter learning curve and lower cost.

Visual experience during phacoemulsification under topical versus retrobulbar anesthesia: results of a prospective, randomized, controlled trial.

PURPOSE: To compare the subjective visual experience of cataract patients during phacoemulsification and intraocular lens implantation under topical anesthesia (TA) vs retrobulbar anesthesia (RA). DESIGN: Prospective, randomized, controlled trial. METHODS: Three hundred six cataract patients eligible for phacoemulsification and intraocular lens implantation were randomized to receive either TA or RA during surgery by one of three surgeons. The surgeons were familiar with both anesthetic techniques and operated on the patients using the technique to which the patients were randomized. A masked interviewer conducted in-person interviews with the patients using a standardized questionnaire about their intraoperative visual experience and their reaction to their visual experience between 30 minutes and 4 hours after the surgery. RESULTS: Two patients (one in each group) had intraoperative posterior capsule rupture and were excluded from analysis. There was no statistically significant difference between TA (n = 154) and RA (n = 150) groups, except that more males compared with females had TA (P = .03). More patients who had TA reported perception of light (P < .001) and colors (P < .001) and a change (either increase or decrease) in light brightness during the course of the surgery (P < .001). There was no statistically significant difference in the proportions of patients who saw movements, flashes, instruments, or the surgeon or medical staff during the operation and who found their visual sensations frightening in the two groups. However, 10.4% in the TA group and 9.3% in the RA group found their visual experience frightening. CONCLUSIONS: More patients undergoing cataract surgery under TA compared with RA reported perception of light, colors, and a change in light brightness. A significant proportion of patients in both groups found the visual experience frightening.

Microfluidic peroxidase biochip for polyphenol synthesis.

An enzyme-containing microfluidic biochip has been developed for the oxidative polymerization of phenols. The biochip consists of a simple T-junction with two feed reservoirs 20 mm apart and a microreaction channel 30 mm long. The channel is 15 microm deep and 200 microm wide at the center, giving a reaction volume of 90 nL. The biochip was fabricated using conventional photolithographic methods on a glass substrate etched using a HF-based solution. Fluid transport was enabled using electroosmotic flow. Soybean peroxidase was used as the phenol oxidizing catalyst, and in the presence of p-cresol and H(2)O(2), essentially complete conversion of the H(2)O(2) (the limiting substrate) occurred in the microchannel at a flow rate of ca. 290 nL/min. Thus, peroxidase was found to be intrinsically active even upon dramatic scale-down as achieved in microfluidic reactors. These results were extended to a series of phenols, thereby demonstrating that the microfluidic peroxidase reactor may have application in high-throughput screening of phenolic polymerization reactions for use in phenolic resin synthesis. Finally, rapid growth of poly(p-cresol) on the walls of the microreaction channel could be performed in the presence of higher H(2)O(2) concentrations. This finding suggests that solution-phase peroxidase catalysis can be used in the controlled deposition of polymers on the walls of microreactors.