The Role of Cognitive Function in Postoperative Weight Loss Outcomes: 36-Month Follow-Up

Background

Cognitive dysfunction is associated with reduced postoperative weight loss up to 2 years following surgery, though the role of cognition at more extended follow-up is not yet understood. Thirty-six months following bariatric surgery, we retrospectively compared obese and non-obese patients on 12-week postoperative cognitive performance. We hypothesized that early postoperative cognitive dysfunction would predict higher body mass index (BMI) and lower percent weight loss (%WL) in the total sample at 36 month follow-up.

Materials and Methods

Fifty-five individuals undergoing bariatric surgery completed cognitive testing at preoperative baseline and serial postoperative timepoints, including 12 weeks and 36 months. Cognitive test scores were normed for demographic variables. Percent weight loss (%WL) and body mass index (BMI) were calculated at 36-month follow-up.

Results

Adjusting for gender, baseline cognitive function, and 12-week %WL, 12-week global cognitive test performance predicted 36 month postoperative %WL and BMI. Partial correlations revealed recognition memory, working memory, and generativity were most strongly related to weight loss.

Conclusion

Cognitive function shortly after bariatric surgery is closely linked to extended postoperative weight loss at 36 months. Further work is necessary to clarify mechanisms underlying the relationship between weight loss, durability, and cognitive function, including contribution of adherence, as this may ultimately help identify individuals in need of tailored interventions to optimize postoperative weight loss.     

Evaluation of a novel strain of infectious bronchitis virus emerged as a result of spike gene recombination between two highly diverged parent strains

The emergence of new variant strains of the poultry pathogen infectious bronchitis virus (IBV) is continually reported worldwide, owing to the labile nature of the large single-stranded RNA IBV genome. High resolution melt curve analysis previously detected a variant strain, N1/08, and the present study confirmed that this strain had emerged as a result of recombination between Australian subgroup 2 and 3 strains in the spike gene region, in a similar manner reported for turkey coronaviruses. The S1 gene for N1/08 had highest nucleotide similarity with subgroup 2 strains, which is interesting considering subgroup 2 strains have not been detected since the early 1990s. SimPlot analysis of the 7.2-kb 3′ end of the N1/08 genome with the same region for other Australian reference strains identified the sites of recombination as immediately upstream and downstream of the S1 gene. A pathogenicity study in 2-week-old chickens found that N1/08 had similar pathogenicity for chicken respiratory tissues to that reported for subgroup 2 strains rather than subgroup 3 strains. The results of this study demonstrate that recombination is a mechanism utilized for the emergence of new strains of IBV, with the ability to alter strain pathogenicity in a single generation.     

Binge eating disorder: A multisite field trial of the diagnostic criteria

Diagnostic criteria have been developed for a new eating disorder, binge eating disorder (BED), to describe the many individuals who have problems with recurrent binge eating but do not engage in the characteristic compensatory behaviors of bulimia nervosa, vomiting, or use of laxatives. The results of a multisite field trial involving 1,984 subjects indicate that the disorder is common (30.1%) among subjects attending hospital-affiliated weight control programs, but is relatively rare in the community (2.0%). The disorder is more common in females than in males and is associated with severity of obesity and a history of marked weight fluctuations. Based on these results, the DSM-IV Work Group on Eating Disorders has recommended that the disorder be considered for inclusion in DSM-IV, either as an official category or in an appendix of categories requiring further study.     

Fragile sites and high-resolution chromosome studies in multiple endocrine neoplasia type 2A

Affected individuals from four kindreds with multiple endocrine neoplasia type 2A syndrome (MEN-2A), were studied for the possible existence of a specific fragile site that might be associated with the MEN-2A gene. The chromosomes were also examined with high-resolution banding with particular emphasis on those chromosomes (#1, 10, 20, and 22) that have been implicated by previous studies from several laboratories as being associated with this disease. There was no evidence for a unique fragile site or a unique high-resolution banding pattern in subjects with MEN-2A. These findings, in combination with all previous cytogenetic studies, indicate that it is unlikely that current techniques will be useful in developing a simple cytogenetic test for this disease.     

Metformin and Rapamycin Reduce Pancreatic Cancer Growth in Obese Prediabetic Mice by Distinct MicroRNA-Regulated Mechanisms

Metformin treatment is associated with a decreased risk and better prognosis of pancreatic cancer (PC) in patients with type 2 diabetes, but the mechanism of metformin’s PC growth inhibition in the context of a prediabetic state is unknown. We used a Panc02 pancreatic tumor cell transplant model in diet-induced obese (DIO) C57BL/6 mice to compare the effects of metformin and the direct mammalian target of rapamycin (mTOR) inhibitor rapamycin on PC growth, glucose regulation, mTOR pathway signaling, and candidate microRNA (miR) expression. In DIO/prediabetic mice, metformin and rapamycin significantly reduced pancreatic tumor growth and mTOR-related signaling. The rapamycin effects centered on decreased mTOR-regulated growth and survival signaling, including increased expression of let-7b and cell cycle–regulating miRs. Metformin (but not rapamycin) reduced glucose and insulin levels and expression of miR-34a and its direct targets Notch, Slug, and Snail. Metformin also reduced the number and size of Panc02 tumor spheres in vitro and inhibited the expression of Notch in spheroids. Our results suggest that metformin and rapamycin can both inhibit pancreatic tumor growth in obese, prediabetic mice through shared and distinct mechanisms. Metformin and direct mTOR inhibitors, alone or possibly in combination, represent promising intervention strategies for breaking the diabetes-PC link.     

The Effect of Water Absorption on Acrylic Surface Properties

PURPOSE: The aim of the present study was to determine whether an increased water content during thermal cycling of hot water-treated acrylic was associated with a reduction in surface hardness and an increased opacity or whitening of the surface. MATERIALS AND METHODS: Ten acrylic samples were treated with 30 soak cycles (cycle duration, 24 hours), using warm water (40 degrees C) and an alkaline peroxide tablet (Efferdent control group); a further ten samples were treated with boiling water (100 degrees C) and one Efferdent tablet (experimental group). Indentation hardness of the acrylic specimens was measured prior to and immediately following the completion of the warm and hot water treatments, using an automated micro-indentation system. The hydrated acrylic specimens were then allowed to air dry at room temperature (20 degrees C) and were weighed weekly until they had obtained a constant dry weight. The loss in weight of the acrylic specimens represented the maximum water absorption. RESULTS: The hot water-treated specimens were much whiter than the warm water-treated specimens. The mean reduction in hardness (H(IT)) of the acrylic specimens following the treatment with hot water and alkaline peroxide tablet was 12.9%. Treatment with warm water and alkaline peroxide resulted in a slight increase in mean hardness (2.63%). There was a significant correlation between the water content of the acrylic specimens after treatment and the percentage of change in indentation hardness (r= 0.495, p= 0.026). CONCLUSIONS: The hot water treatment of the acrylic was associated with a significant reduction in hardness. We attribute the whitening and reduction in the hardness of the hot water-treated specimens to absorption of water and a disruption of the acrylic surface structure.