The novel use of a biodegradable stent placed by percutaneous transhepatic cholangiography for the treatment of a hepaticojejunostomy biliary leak following an extended left hepatectomy and pancreaticoduodenectomy

A 61-year-old man presented with jaundice, and subsequently underwent an extended left hepatectomy and pancreaticoduodenectomy for a cholangiocarcinoma invading the head of the pancreas. The patient developed sepsis due to a biliary leak at the hepaticojejunostomy. We describe the original use of a biodegradable stent, deployed via percutaneous transhepatic cholangiography into the Roux limb, resulting in good drainage and resolution of sepsis. The chief benefit of this procedure is the lack of need for subsequent removal as well as purported reduced biofilm accumulation. We believe this to be the first reported case of this type and the literature surrounding the subject is also discussed.

Arterial pressure above the upper cerebral autoregulation limit during cardiopulmonary bypass is associated with postoperative delirium

BACKGROUND

Mean arterial pressure (MAP) below the lower limit of cerebral autoregulation during cardiopulmonary bypass (CPB) is associated with complications after cardiac surgery. However, simply raising empiric MAP targets during CPB might result in MAP above the upper limit of autoregulation (ULA), causing cerebral hyperperfusion in some patients and predisposing them to cerebral dysfunction after surgery. We hypothesized that MAP above an ULA during CPB is associated with postoperative delirium.

METHODS

Autoregulation during CPB was monitored continuously in 491 patients with the cerebral oximetry index (COx) in this prospective observational study. COx represents Pearson's correlation coefficient between low-frequency changes in regional cerebral oxygen saturation (measured with near-infrared spectroscopy) and MAP. Delirium was defined throughout the postoperative hospitalization based on clinical detection with prospectively defined methods.

RESULTS

Delirium was observed in 45 (9.2%) patients. Mechanical ventilation for >48 h [odds ratio (OR), 3.94; 95% confidence interval (CI), 1.72-9.03], preoperative antidepressant use (OR, 3.0; 95% CI, 1.29-6.96), prior stroke (OR, 2.79; 95% CI, 1.12-6.96), congestive heart failure (OR, 2.68; 95% CI, 1.28-5.62), the product of the magnitude and duration of MAP above an ULA (mm Hg h; OR, 1.09; 95% CI, 1.03-1.15), and age (per year of age; OR, 1.01; 95% CI, 1.01-1.07) were independently associated with postoperative delirium.

CONCLUSIONS

Excursions of MAP above the upper limit of cerebral autoregulation during CPB are associated with risk for delirium. Optimizing MAP during CPB to remain within the cerebral autoregulation range might reduce risk of delirium.

CLINICAL TRIAL REGISTRATION

clinicaltrials.gov NCT00769691 and NCT00981474.

Registered Replication Report: Schooler and Engstler-Schooler (1990)

Trying to remember something now typically improves your ability to remember it later. However, after watching a video of a simulated bank robbery, participants who verbally described the robber were 25% worse at identifying the robber in a lineup than were participants who instead listed U.S. states and capitals-this has been termed the "verbal overshadowing" effect (Schooler & Engstler-Schooler, 1990). More recent studies suggested that this effect might be substantially smaller than first reported. Given uncertainty about the effect size, the influence of this finding in the memory literature, and its practical importance for police procedures, we conducted two collections of preregistered direct replications (RRR1 and RRR2) that differed only in the order of the description task and a filler task. In RRR1, when the description task immediately followed the robbery, participants who provided a description were 4% less likely to select the robber than were those in the control condition. In RRR2, when the description was delayed by 20 min, they were 16% less likely to select the robber. These findings reveal a robust verbal overshadowing effect that is strongly influenced by the relative timing of the tasks. The discussion considers further implications of these replications for our understanding of verbal overshadowing.

Monte Carlo simulation of explosive detection system based on a Deuterium-Deuterium (D-D) neutron generator

An explosive detection system based on a Deuterium-Deuterium (D-D) neutron generator has been simulated using the Monte Carlo N-Particle Transport Code (MCNP5). Nuclear-based explosive detection methods can detect explosives by identifying their elemental components, especially nitrogen. Thermal neutron capture reactions have been used for detecting prompt gamma emission (10.82MeV) following radiative neutron capture by (14)N nuclei. The explosive detection system was built based on a fully high-voltage-shielded, axial D-D neutron generator with a radio frequency (RF) driven ion source and nominal yield of about 10(10) fast neutrons per second (E=2.5MeV). Polyethylene and paraffin were used as moderators with borated polyethylene and lead as neutron and gamma ray shielding, respectively. The shape and the thickness of the moderators and shields are optimized to produce the highest thermal neutron flux at the position of the explosive and the minimum total dose at the outer surfaces of the explosive detection system walls. In addition, simulation of the response functions of NaI, BGO, and LaBr3-based γ-ray detectors to different explosives is described.

Differential impact of changes in adiposity distribution on insulin resistance and adiponectin variations over 4 years in normal weight young adults

The aim of the study was to evaluate the influence of weight gain and changes in adiposity distribution on insulin resistance and circulating adiponectin variations over 4 years in free-living normal weight young adults. In this prospective observational cohort (n=42 women, 18 men), anthropometric measurements and blood samples were collected in the fasting state at baseline and at 4 years. Insulin resistance was estimated using the homeostatic model assessment (HOMA-IR). Circulating adiponectin levels were determined by radioimmunoassay. To investigate increase in adiposity more specifically, subsidiary analyses were performed in a subgroup of individuals (n=31) who gained adiposity over the course of the 4-year follow-up (defined as gain >1% in percent body fat). Regression analyses were performed to adjust for sex, age, parental education, lifestyle, and fitness levels. At baseline, the participants were young adults (age=20.0 years old) in the normal weight range [body mass index (BMI)=22.7 kg/m2 (IQR=21.1-24.4)]. Median change in body fat percentage was +1.4% (IQR=-0.3-3.4; p=0.01) and in waist circumference was +1.2 cm (IQR=-2.6-5.3; p=0.05). In the subgroup of individuals who gained more than 1% body fat, increase in HOMA-IR was associated with an increase in BMI (r=0.44; p=0.01; p<0.01 in fully adjusted model), while decrease in adiponectin levels was associated with an increase in waist circumference (r=-0.38; p=0.03) but this was no longer significant after adjustment for sex and other potential confounders (p=0.14). In a population of young adults, small variations in adiposity within the normal weight range were associated with increase in insulin resistance.

Homozygous mutation of MTPAP causes cellular radiosensitivity and persistent DNA double-strand breaks

The study of rare human syndromes characterized by radiosensitivity has been instrumental in identifying novel proteins and pathways involved in DNA damage responses to ionizing radiation. In the present study, a mutation in mitochondrial poly-A-polymerase (MTPAP), not previously recognized for its role in the DNA damage response, was identified by exome sequencing and subsequently associated with cellular radiosensitivity. Cell lines derived from two patients with the homozygous MTPAP missense mutation were radiosensitive, and this radiosensitivity could be abrogated by transfection of wild-type mtPAP cDNA into mtPAP-deficient cell lines. Further analysis of the cellular phenotype revealed delayed DNA repair, increased levels of DNA double-strand breaks, increased reactive oxygen species (ROS), and increased cell death after irradiation (IR). Pre-IR treatment of cells with the potent anti-oxidants, α-lipoic acid and n-acetylcysteine, was sufficient to abrogate the DNA repair and clonogenic survival defects. Our results firmly establish that mutation of the MTPAP gene results in a cellular phenotype of increased DNA damage, reduced repair kinetics, increased cell death by apoptosis, and reduced clonogenic survival after exposure to ionizing radiation, suggesting a pathogenesis that involves the disruption of ROS homeostasis.

Examining the link between personality and laterality in a feral guppy Poecilia reticulata population

This study examined whether variation in the strength and direction of lateralization in a detour task was linked with variation in three common personality measurements: boldness, activity and sociability, in a population of wild guppies Poecilia reticulata. Additionally, the aim was to determine whether any consistent correlations between these behavioural traits, known as behavioural syndromes, were present in the study population. The results revealed that all three personality traits were highly repeatable over time in both sexes. Evidence of a complex syndrome in the form of a correlation between boldness, sociability and activity was found; however, this relationship was only present in males. Males that were more active in a familiar environment emerged more quickly from shelter into a novel environment and were more social. In general, male P. reticulata were bold, active and antisocial compared to females, with these differences probably a reflection of opposing life-history strategies. Only a weak link between the strength of cerebral lateralisation and personality was discovered and this was mediated by sex.

Multispecies coexistence of trees in tropical forests: spatial signals of topographic niche differentiation increase with environmental heterogeneity

Neutral and niche theories give contrasting explanations for the maintenance of tropical tree species diversity. Both have some empirical support, but methods to disentangle their effects have not yet been developed. We applied a statistical measure of spatial structure to data from 14 large tropical forest plots to test a prediction of niche theory that is incompatible with neutral theory: that species in heterogeneous environments should separate out in space according to their niche preferences. We chose plots across a range of topographic heterogeneity, and tested whether pairwise spatial associations among species were more variable in more heterogeneous sites. We found strong support for this prediction, based on a strong positive relationship between variance in the spatial structure of species pairs and topographic heterogeneity across sites. We interpret this pattern as evidence of pervasive niche differentiation, which increases in importance with increasing environmental heterogeneity.

Markers of systemic inflammation predict survival in patients with advanced renal cell cancer

Background:

The host inflammatory response has a vital role in carcinogenesis and tumour progression. We examined the prognostic value of inflammatory markers (albumin, white-cell count and its components, and platelets) in pre-treated patients with advanced renal cell carcinoma (RCC).

Methods:

Using data from a randomised trial, multivariable proportional hazards models were generated to examine the impact of inflammatory markers and established prognostic factors (performance status, calcium, and haemoglobin) on overall survival (OS). We evaluated a new prognostic classification incorporating additional information from inflammatory markers.

Results:

Of the 416 patients, 362 were included in the analysis. Elevated neutrophil counts, elevated platelet counts, and a high neutrophil–lymphocyte ratio were significant independent predictors for shorter OS in a model with established prognostic factors. The addition of inflammatory markers improves the discriminatory value of the prognostic classification as compared with established factors alone (C-statistic 0.673 vs 0.654, P=0.002 for the difference), with 25.8% (P=0.004) of patients more appropriately classified using the new classification.

Conclusion:

Markers of systemic inflammation contribute significantly to prognostic classification in addition to established factors for pre-treated patients with advanced RCC. Upon validation of these data in independent studies, stratification of patients using these markers in future clinical trials is recommended.

Perceptions and experiences of environmental health risks among new mothers: a qualitative study in Ontario, Canada

There is a growing awareness and concern in contemporary societies about potential health impacts of environmental contaminants on children. Mothers are traditionally more involved than other family members in managing family health and household decisions and thus targeted by public health campaigns to minimise risks. However little is known about how new mothers perceive and experience environmental health risks to their children. In 2010, we undertook a parallel case study using qualitative, in-depth interviews with new mothers and focus groups with public health key informants in two Public Health Units in Ontario Province, Canada. We found that the concern about environmental hazards among participants ranged from having no concerns to actively incorporating prevention into daily life. Overall, there was a common perception among participants that many risks, particularly in the indoor environment, were controllable and therefore of little concern. But environmental risks that originate outside the home were viewed as less controllable and more threatening. In response to such threats, mothers invoked coping strategies such as relying on the capacity of children's bodies to adapt. Regardless of the strategies adopted, actions (or inactions) were contingent upon active information seeking. We also found an optimistic bias in which new mothers reported that other children were at greater risk despite similar environmental circumstances. The findings suggest that risk communication experts must attend to the social and environmental contexts of risk and coping when designing strategies around risk reducing behaviours.

Subsyndromal depression and anxiety in older adults: health related, functional, cognitive and diagnostic implications

Subsyndromal depression in later life is common in primary care. Comorbid anxiety disorders could exacerbate the negative effect of subsyndromal depression on functioning, health-related quality of life, comorbidity and/or cognition. We examined anxiety disorders co-existing with subsyndromal depression in participants ≥ age 50 in an NIH trial of Problem Solving Therapy for Primary Care for indicated prevention of major depression. There were 247 participants, with Centers for Epidemiologic Studies - Depression scores ≥ 11. Participants could have multiple psychiatric diagnoses: 22% of the sample had no DSM IV diagnosis; 39% of the sample had only 1 DSM IV diagnosis; 28% had 2 diagnoses; 6% had 3 DSM IV diagnoses; 4% had 4 DSM IV diagnoses; and 1% had 5 diagnoses. Furthermore, 34% of participants had a current comorbid DSM IV diagnosis of a syndromal anxiety disorder. We hypothesized that those with subsyndromal depression, alone relative to those with co-existing anxiety disorders, would report better health-related quality of life, less disability, less medical comorbidity and less cognitive impairment. However, there were no differences in quality of life based on the SF 12 nor in disability based on Late Life Function and Disability Instrument scores. There were no differences in medical comorbidity based on the Cumulative Illness Scale-Geriatrics scale scores nor in cognitive function based on the Executive Interview (EXIT), Hopkins Verbal Learning Test-Revised and Mini-Mental Status Exam. Our findings suggest that about one third of participants 50 years and older with subsyndromal depression have comorbid anxiety disorders; however, this does not appear to be associated with worse quality of life, functioning, disability, cognitive function or medical comorbidity.

Sustained outcomes of a peer-taught family education program on mental illness

OBJECTIVE

This study examines 6-month follow-up data from participants in a randomized trial of a peer-driven 12-session family support and education program, called family-to-family (FTF) and offered by the US National Alliance on Mental Illness, to determine whether improvements in distress, family functioning, coping and empowerment were sustained.

METHOD

Individuals randomized to the FTF condition were assessed after program completion and then 3 months later on measures of distress, family functioning, coping, and empowerment. We used a multilevel regression model (sas proc mixed) to test for significant changes over time (baseline, 3 and 9 months).

RESULTS

All significant benefits that FTF participants gained between baseline and immediately post-FTF were sustained at 9 months including reduced anxiety, improved family problem-solving, increased positive coping, and increased knowledge. Greater class attendance was associated with larger increases in empowerment and reductions in depression and displeasure with ill relative.

CONCLUSION

Evidence suggests that benefits of the FTF program were sustained for at least 6 months without any additional boosters or supports. Peer-based programs may produce sustained benefits for individuals seeking help in addressing challenges and stresses related to having a family member with a mental illness.

The genetics of Canadian type 3 von Willebrand disease: further evidence for co-dominant inheritance of mutant alleles

BACKGROUND

Type 3 von Willebrand disease (VWD) is the most severe form of the disease and is classically inherited in an autosomal recessive fashion.

OBJECTIVES

The aim of the current study was to investigate the molecular pathogenesis of a Canadian cohort of type 3 VWD patients.

PATIENTS AND METHODS

Thirty-four families comprised of 100 individuals were investigated. Phenotypic data, including bleeding scores (BS), von Willebrand factor (VWF) laboratory values and anti-VWF inhibitor status were included as well as sequence analysis.

RESULTS

We identified 31 different mutations (20 novel): 8 frameshift, 5 splice site, 9 nonsense, 1 gene conversion, 6 missense and 2 partial gene deletion mutations. The majority of mutations identified were in the propeptide (42%); index cases (IC) with these mutations exhibited more severe bleeding (BS = 22) than those with mutations elsewhere in VWF (BS = 13). Sixty-two out of 68 (91%) mutant alleles were identified. Twenty-nine IC (85%) had a VWF null genotype identified; 17 homozygous, 12 compound heterozygous. In five IC (15%), two mutant VWF alleles were not identified to explain the type 3 VWD phenotype. In four ICs only one mutant VWF allele was identified and in one IC no mutant VWF alleles were identified.

CONCLUSIONS

We have investigated the molecular pathogenesis of a Canadian cohort of type 3 VWD patients. Obligate carriers are not phenotypically silent in the Canadian population; 48% have been diagnosed with type 1 VWD. In approximately 50% of families in this study the inheritance pattern for type 3 VWD is co-dominant and not recessive.