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1.

Objective

Patient selection for open lower extremity revascularization in patients with chronic kidney disease (CKD) remains a clinical challenge. This study investigates the impact of CKD on early graft failure, postoperative complications, and mortality in patients undergoing lower extremity bypass for critical limb ischemia.

Methods

The National Surgical Quality Improvement Program database was queried for all patients with critical limb ischemia from 2012 to 2015 who underwent lower extremity bypass using the targeted vascular set. The glomerular filtration rate was calculated using the Chronic Kidney Disease Epidemiology Collaboration Study equation. CKD categories were determined from the National Kidney Foundation Kidney Disease Outcomes Quality Initiative staging criteria. Patients were classified into three groups: CKD stages 3 or lower (mild to moderate CKD), CKD stages 4 or 5 (severe CKD), and on hemodialysis (HD). Multiple variable analysis was used to examine graft failure, mortality, and postoperative complications.

Results

The Surgical Quality Improvement Program database identified 6978 patients who underwent infrainguinal lower extremity arterial bypass during the study period. There were 6101 patients (87.4%) with mild to moderate CKD, 327 (4.7%) with severe CKD, and 550 (7.9%) on HD. Patients with severe CKD and on HD were more likely to have revascularization for tissue loss (54.9% vs 68.8% and 74.7%; P < .01). Patients with severe CKD and those on HD had higher rates of early graft failure, postoperative myocardial infarction, and rates of reoperation. Multiple variable analysis confirmed these results showing that HD was associated with postoperative myocardial infarction, readmission, and increased mortality. It also demonstrated that severe CKD was associated with graft failure (odds ratio [OR], 1.67; 95% confidence interval [CI], 1.12-2.50; P = .01), postoperative myocardial infarction (OR, 2.16; 95% CI, 1.35-3.45; P < .01), and readmission (OR, 1.38; 95% CI, 1.06-1.80; P = .02). Other factors associated with graft failure include functional status (OR, 1.39; 95% CI, 1.08-1.80; P = .01), African American race (OR, 1.72; 95% CI, 1.39-2.13; P < .01), and distal bypass (OR, 1.33; 95% CI, 1.09-1.61; P < .01).

Conclusions

CKD is a significant predictor of perioperative morbidity after lower extremity bypass. Patients with severe CKD have worse postoperative outcomes without increased mortality. Those on HD have worse survival and postoperative outcomes.  相似文献   
2.
Transmission is a potential property of live viral vaccines that remains largely unexploited but may lie within the realm of many engineering designs. While likely unacceptable for vaccines of humans, transmission may be highly desirable for vaccines of wildlife, both to protect natural populations and also to limit zoonotic transmissions into humans. Defying intuition, transmission alone does not guarantee that a vaccine will perform well: the benefit of transmission over no transmission depends on and increases with the basic reproductive number of the vaccine, R0. The R0 of an infectious agent in a homogeneous population is typically considered to be a fixed number, but some evidence suggests that dissemination of transmissible vaccines may change through time. One obvious possibility is that transmission will be greater from hosts directly vaccinated than from hosts who acquire the vaccine passively, but other types of change might also accrue. Whenever transmission changes over time, the R0 estimated from directly vaccinated hosts will not reflect the vaccine’s long term impact. As there is no theory on the consequences of changing transmission rates for a vaccine, we derive conditions for a transmissible vaccine with varying transmission rates to protect a population from pathogen invasion. Being the first in the transmission chain, the R0 from directly vaccinated hosts has a larger effect than those from later steps in the chain. This mathematical property reveals that a transmissible vaccine with low long term transmission may nonetheless realize a big impact if early transmission is high. Furthermore, there may be ways to artificially elevate early transmission, thereby achieving high herd immunity from transmission while ensuring that the vaccine will ultimately die out.  相似文献   
3.

Background

Nutrition specialists are considered key members of multicomponent pediatric weight management intervention teams, but to date, their contribution has not been quantified.

Objective

The purpose of this systematic review was to estimate the effectiveness of interventions provided by treatment teams that include a nutrition specialist on pediatric weight management outcomes, including body mass index (BMI), BMI z score, and waist circumference when compared with treatment teams that do not include a nutrition specialist.

Methods

The results of a comprehensive literature search and a systematic and more targeted update of that search were included in the meta-analyses: a search of controlled trials published between July 2005 and April 2012, conducted during the 2015 Pediatric Weight Management Update Project of the Academy of Nutrition and Dietetics Evidence Analysis Library, and an update search of controlled trials published between May 2012 and December 2015 focusing on a more specific topic within the previous search. Studies included overweight and/or obese patients aged 6 to 18 years receiving outpatient weight management treatment. Data extraction of all studies identified was performed using a standardized tool. The resulting data from the search and the systematic update were merged. Ninety-nine studies and 209 study arms were included in the analysis. An exploratory meta-analysis using alternative meta-analytic methods designed for complex, heterogenous interventions was conducted to identify relative contributions by intervention provider category at selected time points. Meta-regression analyses were used to evaluate significant differences from the reference category for each provider category.

Results

The nutrition specialist-only condition resulted in increased reductions in BMI z score compared with behavioralist-only, combined nutrition specialist and behavioralist, and neither nutrition specialist or behavioralist category (reference) throughout the analysis. Meta-regression analysis indicated that the difference in BMI z score between the nutrition specialist-only category and the reference category was significant at 3 to <6 months, 6 months to <1 year, and 1-year to 2-year time points (P=0.01, P=0.05, and P=0.01, respectively). There were smaller increases in BMI over time for the nutrition specialist-only provider category compared with reference categories, and this difference was significant at the 3 to <6 months and 1-year to 2-years time points (P=0.001 and P=0.05, respectively). There were no significant differences among provider categories for waist circumference at any time point.

Conclusions

Indirect evidence indicated that pediatric weight management outcomes for BMI z score and BMI at selected time points appeared to be better when a nutrition specialist was involved in delivering care.  相似文献   
4.
locStra is an ‐package for the analysis of regional and global population stratification in whole‐genome sequencing (WGS) studies, where regional stratification refers to the substructure defined by the loci in a particular region on the genome. Population substructure can be assessed based on the genetic covariance matrix, the genomic relationship matrix, and the unweighted/weighted genetic Jaccard similarity matrix. Using a sliding window approach, the regional similarity matrices are compared with the global ones, based on user‐defined window sizes and metrics, for example, the correlation between regional and global eigenvectors. An algorithm for the specification of the window size is provided. As the implementation fully exploits sparse matrix algebra and is written in C++, the analysis is highly efficient. Even on single cores, for realistic study sizes (several thousand subjects, several million rare variants per subject), the runtime for the genome‐wide computation of all regional similarity matrices does typically not exceed one hour, enabling an unprecedented investigation of regional stratification across the entire genome. The package is applied to three WGS studies, illustrating the varying patterns of regional substructure across the genome and its beneficial effects on association testing.  相似文献   
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