40 research outputs found
Distance distribution in configuration model networks
We present analytical results for the distribution of shortest path lengths
between random pairs of nodes in configuration model networks. The results,
which are based on recursion equations, are shown to be in good agreement with
numerical simulations for networks with degenerate, binomial and power-law
degree distributions. The mean, mode and variance of the distribution of
shortest path lengths are also evaluated. These results provide expressions for
central measures and dispersion measures of the distribution of shortest path
lengths in terms of moments of the degree distribution, illuminating the
connection between the two distributions.Comment: 28 pages, 7 figures. Accepted for publication in Phys. Rev.
Analytical results for the distribution of shortest path lengths in random networks
We present two complementary analytical approaches for calculating the
distribution of shortest path lengths in Erdos-R\'enyi networks, based on
recursion equations for the shells around a reference node and for the paths
originating from it. The results are in agreement with numerical simulations
for a broad range of network sizes and connectivities. The average and standard
deviation of the distribution are also obtained. In the case that the mean
degree scales as with the network size, the distribution becomes
extremely narrow in the asymptotic limit, namely almost all pairs of nodes are
equidistant, at distance from each other. The
distribution of shortest path lengths between nodes of degree and the rest
of the network is calculated. Its average is shown to be a monotonically
decreasing function of , providing an interesting relation between a local
property and a global property of the network. The methodology presented here
can be applied to more general classes of networks.Comment: 12 pages, 4 figures, accepted to EP
Human Liver Cells Expressing Albumin and Mesenchymal Characteristics Give Rise to Insulin-Producing Cells
Activation of the pancreatic lineage in the liver has been suggested as a potential autologous cell replacement therapy for diabetic patients. Transcription factors-induced liver-to-pancreas reprogramming has been demonstrated in numerous species both in vivo and in vitro. However, human-derived liver cells capable of acquiring the alternate pancreatic repertoire have never been characterized. It is yet unknown whether hepatic-like stem cells or rather adult liver cells give rise to insulin-producing cells. Using an in vitro experimental system, we demonstrate that proliferating adherent human liver cells acquire mesenchymal-like characteristics and a considerable level of cellular plasticity. However, using a lineage-tracing approach, we demonstrate that insulin-producing cells are primarily generated in cells enriched for adult hepatic markers that coexpress both albumin and mesenchymal markers. Taken together, our data suggest that adult human hepatic tissue retains a substantial level of developmental plasticity, which could be exploited in regenerative medicine approaches
Correlation between single limb support phase and self-evaluation questionnaires in knee osteoarthritis populations
Purpose. To investigate the correlation between single limb support (SLS) phase (% of gait cycle) and the Western Ontario and McMaster University Osteoarthritis Index (WOMAC) questionnaire and Medical Outcomes Study 36-Item Short-Form Health Survey (SF-36 Health Survey) in patients with knee osteoarthritis (OA)
A non-invasive biomechanical device and treatment for patients following total hip arthroplasty: results of a 6-month pilot investigation
Differences in gait patterns, pain, function and quality of life between males and females with knee osteoarthritis: a clinical trial
<p>Abstract</p> <p>Background</p> <p>The aim of this study was to gain a deeper understanding of the gender differences in knee osteoarthritis (OA) by evaluating the differences in gait spatio-temporal parameters and the differences in pain, quality of life and function between males and females suffering from knee OA.</p> <p>Methods</p> <p>49 males and 85 females suffering from bilateral medial compartment knee OA participated in this study. Each patient underwent a computerized gait test and completed the WOMAC questionnaire and the SF-36 health survey. Independent t-tests were performed to examine the differences between males and females in age, BMI, spatio-temporal parameters, the WOMAC questionnaire and the SF-36 health survey.</p> <p>Results</p> <p>Males and females had different gait patterns. Although males and females walked at the same walking speed, cadence and step length, they presented significant differences in the gait cycle phases. Males walked with a smaller stance and double limb support, and with a larger swing and single limb support compared to females. In addition, males walked with a greater toe out angle compared to females. While significant differences were not found in the WOMAC subscales, females consistently reported higher levels of pain and disability.</p> <p>Conclusion</p> <p>The spatio-temporal differences between genders may suggest underlying differences in the gait strategies adopted by males and females in order to reduce pain and cope with the loads acting on their affected joints, two key aspects of knee OA. These gender effects should therefore be taken into consideration when evaluating patients with knee OA.</p> <p>Trial Registration</p> <p>The study is registered in the NIH clinical trial registration, protocol No. NCT00599729.</p
The Impact of Obesity and Associated Comorbidities on the Outcomes after Renal Transplantation with a Living Donor vs. Deceased Donor Grafts
Background: Obesity among kidney transplant (KT) recipients can lead to metabolic comorbidity-associated deaths. This study compares post-KT survival between obese and non-obese patients and outcomes of living donor (LD) and deceased donor (DD) grafts. Methods: Between January 2005–May 2019, 1403 KT recipients from a single center were included in the study, as well as 314 patients (22.4%) with obesity (BMI > 30 kg/m2), 137 DD transplants, and 177 LD transplants. Of the 1089 (77.6%) in the control group (BMI ≤ 30 kg/m2), 384 were DD transplants and 705 LD transplants. The Kaplan–Meier method was used for survival analysis and a Cox regression was used to identify risk factors for graft loss and mortality. Propensity score matching analysis adjusting for age, IHD, and T2DM was performed. Results: The study group had higher incidence of obesity related comorbidities, delayed graft function and primary non function (p < 0.001). One-, 5-and 10-year patient and graft survival were lower in the study group (p < 0.001). Subgroup analysis of graft survival according to type of graft shows a difference in the DD (p = 0.002) but not in the LD group (p = 0.220). However, mortality was higher in both groups (LD, p = 0.045; DD, p = 0.004). Risk factors for mortality were age, T2DM, IHD, and DD, and for graft failure: IHD, BMI, donor age, re-transplant, and DD. Propensity score analysis shows an odds ratio of 0.81 for graft failure and 0.93 for death in the study group (95% CI = 0.55, 1.21, p = 0.3 and CI = 0.59, 1.46, p = 0.7, respectively). Conclusions: Recipient age and metabolic comorbidities should be emphasized when evaluating patients with obesity. We suggest considering weight loss interventions using the new GLP-1 inhibitors and bariatric procedures in selected patients to prepare overweight patients for transplant
The Clinical Manifestation of Immunosuppressive Therapy as a Tool to Improve Immune Monitoring in Renal Transplant Recipients
Introduction: Metrics for post-transplant immune monitoring to prevent over or under immunosuppression in renal transplant recipients (RTRs) are lacking.
Methods: We surveyed 132 RTRs, 38 in the first year post transplant and 94 >1 year post-transplant, to study the clinical expression of immunosuppressive therapy. A questionnaire administered to these RTRs was divided into physical (Q physical) and mental (Q mental) symptoms.
Results: In multivariable models for the association between the calculated Q physical and Q mental scores and different clinical and biochemical variables in the 38 RTRs who filled out the questionnaire 130 times during the first year post-transplant, it was found that mycophenolic acid (MPA) and prednisone use increased the mean Q physical score by 0.59 (95% CI 0.21-0.98, p=0.002) and 0.53 (95% CI 0.26-0.81, p=0.00), respectively, while MPA use increased the mean Q mental score by 0.72 (95% CI 0.31-1.12, p=0.001). Among the 94 RTRs who each completed the questionnaire only once, the odds for the mean Q mental score to be above the median value were more than 3 times higher for RTRs treated vs. non-treated with MPA (OR 3.38, 95% CI 1.1-10.3, p=0.03). MPA-treated RTRs had higher mean scores for questions related to sleep disorders (1.83±1.06 vs. 1.32±0.67 for not treated, p=0.037), to difficulty falling asleep (1.72±1.11 vs. 1.16±0.5, p=0.02), and to depression and anxiety.
Conclusion: We concluded that prednisone and MPA use are associated with an increased Q physical and Q mental scores in RTRs. Routine monitoring of physical and mental status of RTRs should be implemented to improve the diagnosis of overimmunosuppression. Dose reduction or discontinuation of MPA should be considered in RTRs who report sleep disorders, depression and anxiety