Citations

While elevated blood cholesterol has been associated with an increased risk of colorectal cancer (CRC) in observational studies, causality is uncertain. Here we apply a Mendelian randomisation (MR) analysis to examine the potential causal relationship between lipid traits and CRC risk. We used single nucleotide polymorphisms (SNPs) associated with blood levels of total cholesterol (TC), triglyceride (TG), low‐density lipoprotein (LDL), and high‐density lipoprotein (HDL) as instrumental variables (IV). We calculated MR estimates for each risk factor with CRC using SNP‐CRC associations from 9,254 cases and 18,386 controls. Genetically predicted higher TC was associated with an elevated risk of CRC (odds ratios (OR) per unit SD increase = 1.46, 95% confidence interval [CI]: 1.20–1.79, p = 1.68 × 10−4). The pooled ORs for LDL, HDL, and TG were 1.05 (95% CI: 0.92–1.18, p = 0.49), 0.94 (95% CI: 0.84–1.05, p = 0.27), and 0.98 (95% CI: 0.85–1.12, p = 0.75) respectively. A genetic risk score for 3‐hydoxy‐3‐methylglutaryl‐coenzyme A reductase (HMGCR) to mimic the effects of statin therapy was associated with a reduced CRC risk (OR = 0.69, 95% CI: 0.49–0.99, p = 0.046). This study supports a causal relationship between higher levels of TC with CRC risk, and a further rationale for implementing public health strategies to reduce the prevalence of hyperlipidaemia.

Alcohol consumption is a well‐established risk factor for the onset and progression of fatty liver disease. An estimated 90% of heavy drinkers are thought to develop significant liver steatosis. For these reasons, an increased understanding of the molecular basis for alcohol‐induced hepatic steatosis is important. It has become clear that autophagy, a catabolic process of intracellular degradation and recycling, plays a key role in hepatic lipid metabolism. We have shown that Rab7, a small guanosine triphosphatase known to regulate membrane trafficking, acts as a key orchestrator of hepatocellular lipophagy, a selective form of autophagy in which lipid droplets (LDs) are specifically targeted for turnover by the autophagic machinery. Nutrient starvation results in Rab7 activation on the surface of the LD and lysosomal compartments, resulting in the mobilization of triglycerides stored within the LDs for energy production. Here, we examine whether the steatotic effects of alcohol exposure are a result of perturbations to the Rab7‐mediated lipophagic pathway. Rats chronically fed an ethanol‐containing diet accumulated significantly higher levels of fat in their hepatocytes. Interestingly, hepatocytes isolated from these ethanol‐fed rats contained juxtanuclear lysosomes that exhibited impaired motility. These changes are similar to those we observed in Rab7‐depleted hepatocytes. Consistent with these defects in the lysosomal compartment, we observed a marked 80% reduction in Rab7 activity in cultured hepatocytes as well as a complete block in starvation‐induced Rab7 activation in primary hepatocytes isolated from chronic ethanol‐fed animals.Conclusion: A mechanism is supported whereby ethanol exposure inhibits Rab7 activity, resulting in the impaired transport, targeting, and fusion of the autophagic machinery with LDs, leading to an accumulation of hepatocellular lipids and hepatic steatosis. (Hepatology Communications2017;1:140‐152)

96 Background: In the last decade there has been an increase in the incidence of contralateral prophylactic mastectomy (CPM) for unilateral breast cancer. Although many factors have been proposed to explain this trend, the impact of breast reconstruction on the decision to undergo CPM has not been extensively studied. Methods: A retrospective review of breast cancer patients from Surveillance, Epidemiology and End Results (SEER) registry data (2004-2008) was conducted. Characteristics of patients undergoing CPM were evaluated. Results: 71,176 patients with a diagnosis of stage I-III infiltrating ductal or lobular breast cancer underwent mastectomy for their primary lesion. Among these, 10,558 patients (15%) underwent a CPM. A significantly higher proportion of women undergoing CPM had reconstruction performed (44%) than those patients not undergoing CPM (13%), p<0.001. On multivariate analysis (Table), significant variables predicting CPM included age <50 years (OR 10.12), breast reconstruction (OR 3.58), and lobular histology (OR 1.41), all p<0.001. Of the 12,466 patients (18%) who underwent reconstruction, 4,636 (37%) had implant reconstruction, 4,498 (36%) had tissue reconstruction, and 1,122 (9%) had combined tissue/implant reconstruction (no data for 18%). On multivariate analysis, predictors of reconstruction included age <50 years (OR 20.5; CI 18.5-22.7), year of surgery (2008 vs. 2004; OR 1.60; CI 1.49-1.71), low tumor grade (OR 1.19; CI 1.13-1.25) and ER+ status (OR 1.16; 95% CI 1.10-1.23). The use of radiation therapy was associated with a lower likelihood of pursuing reconstruction (OR 0.61; CI 0.58-0.65). Conclusions: Apart from age, the factor most strongly associated with CPM is the decision to have reconstructive surgery performed. This suggests that CPM may not be purely associated with risk-reduction but also with treatment factors such as cosmesis. [Table: see text]

Successful dialysis access necessitates superficial arteriovenous fistula (AVF) placement to facilitate identification of anatomical landmarks for safe cannulation. Suction-assisted lipectomy (SAL) may be an alternative to traditional surgical AVF revision procedures for placing fistulas more superficially. Three patients with an average body mass index of 45.2 kg/m 2 , with inaccessible AVFs due to obesity, underwent ultrasound-guided SAL of their upper extremities. Successful cannulation was achieved within two weeks. A clinically insignificant hematoma and arm swelling occurred in one patient. SAL provides a safe and effective alternative for salvaging deep AVFs for dialysis access in the upper extremities of obese patients.

INTRODUCTION Acellular dermal matrices have been used with increasing frequency in both reconstructive and cosmetic surgery. While many studies have described the safety and morbidity profiles of these materials, little is known about the relative mechanical properties of individual sheets of allograft harvested from distinct donors. METHODS Sixty-two individual sheets of an acellular dermal matrix from distinct lot numbers (signifying different donors of the dermis) were prospectively analyzed before use. Distribution of thickness according to manufacturer specifications in the dry state were as follows: 0.009 inches to 0.013 inches (1 [1.6%]); 0.79 mm to 1.78 mm (3 [4.8%]); 0.79 mm to 2.03 mm (5 [8%]); 0.8 mm to 3.3 mm (1 [1.6%]); 1.8 mm to 3.3 mm (10 [16.1%]) and 28 mm (6 [9.7%]). The size of the matrix was recorded while dry, after hydration and following stretch. The percentage change in surface area was recorded for each lot. RESULTS The 62 reconstructive cases included breast implant reconstruction (2 [3.2%]); ventral hernia repair (11 [17.7%]); abdominal closure following autologous tissue harvest (6 [9.6%]); autologous breast reconstruction (37 [59.6%]); extremity wound closures (3 [4.8%]) and reinforcement of vertical rectus abdominis muscle closure (3 [4.8%]). The mean percentage change in the size of the acellular dermal matrix to the hydrated state was 58% (36 of 62; thickness 0.06 mm to 3.30 mm); the mean percentage change in size from dry state was 7.14% (range 0% to 18.7%). The mean percentage change in the size of the hydrated matrix to the stretched state was 25.7% (range 0.25% to 70.6%). The variability in elasticity among the individual sheets was significant (P<0.0005). CONCLUSION The acellular dermal matrix displayed highly variable elastic properties among distinct donors. This may be significant in procedures in which symmetry is critical.

The deep inferior epigastric artery perforator flap is an option for women desiring autologous tissue breast reconstruction. If this reconstruction fails, other autologous tissue flaps, including the gluteal artery perforator and latis-simus dorsi flaps, may be used for salvage. The anterolateral thigh (ALT) flap offers adequate tissue volume for breast reconstruction, acceptable fat quality and a long vascular pedicle. Other advantages include obviating the need for intraoperative position changes and harvesting tissue outside of the radiation field. Two cases involving ALT flaps used in the setting of deep inferior epigastric artery perforator failure are presented with favourable results. A review of the anatomy of the ALT flap is included.

A novel protein complex facilitates lipid droplet autophagy.

Central (aortic) blood pressure, arterial stiffness, and sympathetic nerve activity increase with age in women. However, it is unknown if the age-related increase in sympathetic activity influences aortic hemodynamics and carotid-femoral pulse wave velocity (cfPWV), an index of central aortic stiffness. The goal of this study was to determine if aortic hemodynamics and cfPWV are directly influenced by sympathetic nerve activity by measuring aortic hemodynamics, cfPWV, and muscle sympathetic nerve activity (MSNA) in women before and during autonomic ganglionic blockade with trimethaphan camsylate. We studied 12 young premenopausal (23 ± 4 yr) and 12 older postmenopausal (57 ± 3 yr) women. These women did not differ in body mass index or mean arterial pressure ( P > 0.05 for both). At baseline, postmenopausal women had higher aortic pulse pressure, augmented pressure, augmentation index adjusted for a heart rate of 75 beats/min, wasted left ventricular pressure energy, and cfPWV than young women ( P < 0.05). During ganglionic blockade, postmenopausal women had a greater decrease in these variables in comparison to young women ( P < 0.05). Additionally, baseline MSNA was negatively correlated with the reductions in aortic pulse pressure, augmented pressure, and wasted left ventricular pressure energy during ganglionic blockade in postmenopausal women ( P < 0.05) but not young women. Baseline MSNA was not correlated with the changes in augmentation index adjusted for a heart rate of 75 beats/min or cfPWV in either group ( P > 0.05 for all). Our results suggest that some aortic hemodynamic parameters are influenced by sympathetic activity to a greater extent in older postmenopausal women than in young premenopausal women.NEW & NOTEWORTHY Autonomic ganglionic blockade results in significant decreases in multiple aortic pulse wave characteristics (e.g., augmented pressure) and central pulse wave velocity in older postmenopausal women but not in young premenopausal women. Certain aortic pulse wave parameters are negatively influenced by sympathetic activity to a greater extent in older postmenopausal women.