Effect of the Branching Pattern of Hydrophobic Dendrons on the Core Structure of Linear‐Dendritic Copolymer Micelles

Hydrophobic dendrons based on different branching patterns, viz. 3,5‐di‐ and 3,4,5‐trisubstituted phenyl rings, consist of the same backbone but exhibit different sizes, shapes, and hydrophobic densities. These dendrons are attached to poly(ethylene glycol) and the core pro­perties of the copolymer micelles are investigated in tetrahydrofuran (THF)/water mixtures by neutron scattering. Two polymers with intermediate hydrophobicity are studied further with variations in the solvent composition and the temperature. The aggregation numbers for 3,4,5‐based dendron copolymers are lower, with more THF molecules of solvation compared with the 3,5‐based dendron copolymer, the difference being greater at higher generations due to different molecular shapes. The micellar core size increases in small steps with dendron size so that dye encapsulation is tuned.

     

Association of pulse pressure,pulse pressure index,and ambulatory arterial stiffness index with kidney function in a cross‐sectional pediatric chronic kidney disease cohort from the CKiD study

The morbidity and mortality of adult and pediatric chronic kidney disease (CKD) and end‐stage renal disease (ESRD) populations are mainly driven by cardiovascular disease (CVD). Improving CVD outcomes focuses on risk assessment of factors including diastolic blood pressure (DBP), systolic blood pressure (SBP), left ventricular mass index (LVMI), pulse pressure (PP), and pulse pressure index (PPi), which is calculated as PP/SBP. These markers are also proven predictors of CKD progression; however, their role in children has not been established. This study aims to evaluate the relationship between PP, PPi, ambulatory arterial stiffness index (AASI), and proteinuria with kidney function in pediatric CKD patients; it is a retrospective analysis of 620 patients (1‐16 years) from the NIDDK Chronic Kidney Disease in Children (CKiD) registry. The authors analyzed data for three separate cohorts: an overall CKD as well as immunological versus non‐immunological cause for CKD groups. An inverse relationship was found between SBP, DBP, and PP with iGFR and LVMI in the overall CKD group. Our immunological CKD subgroup showed significantly higher serum creatinine, SBP, DBP, and PP values with significantly lower serum albumin levels compared to the non‐immunological group. There were no significant differences with iohexol‐based glomerular filtration rate (iGFR), LVMI, PPi, or high‐sensitivity C‐reactive protein (hs‐CRP) between the two groups. A subgroup analysis demonstrated that SBP, DBP, and PP all correlated significantly with LVMI in the immunological CKD patients but not the non‐immunological subgroup. Additionally, AASI data in the overall CKD population were significantly correlated with PP, PPi, and DBP. This study is one of the first to correlate noninvasive measurements of vascular compliance including PP, PPi, and AASI with iGFR and LVMI in a pediatric CKD cohort. Improving our understanding of surrogate markers for early CVD is integral to improving the care of pediatric CKD population as these patients have yet to develop the hard end points of ESRD, heart failure, myocardial infarction, or stroke.     

Deflections in Mandibular Major Connectors: A FEM Study

The major connector is the most vital component critically subjected to maximal stress concentration due to various forces acting on it. The main requirement of a major connector is its resistance to deformation by occlusal stresses. This resistance to deformation is a direct consequence of the rigidity of the major connector. Thus rigidity of the major connector is paramount to resist flexing and torquing forces that could be transmitted to the abutment teeth and other structures as destructive forces. The commonly used major connectors for the mandibular arch are lingual bar and lingual plate. In the present study, the deflection of various major connector designs due to occlusal load is assessed by finite element method. They have been analyzed through finite element models. The differences in the deflection behaviour of mandibular major connector used in Kennedy’s Class I, Class II, Class III, and Class IV edentulous situations have been compared. A CT scan of human edentulous mandible was taken and each section from symphysis to condylar region was projected on a graph paper and three-dimensional volumes were created from connected successive profiles to define the final solid geometry of cortical bone. Six framework models with different mandibular major connectors, lingual bar and lingual plate for Kennedy’s Class I, Class II, Class III, and Class IV situations were created. The three dimensional finite element models corresponding to the geometric model were generated using Ansys’s pre-processor. The model was assigned material properties. A vertical biting force of 20 N was applied. The results showed that the maximum deflection was seen in the saddle area when compared to other areas, i.e., major connector and the occlusal rest regions. The lingual bar in Kennedy’s Class III situation and lingual plate in Kennedy’s Class IV situation showed the least deflection when compared to Class I and Class II (distal extensions) situations. Lingual plate is more rigid major connector than lingual bar.     

Assessment of levels of vascular endothelial growth factor in patients with ESRD and its possible role in cardiovascular morbidity and mortality

Patients with end-stage renal disease (ESRD) are known to have an elevation of a variety of abnormal thrombotic and inflammatory markers associated with high cardiovascular mortality. Vascular endothelial growth factor (VEGF) is also dysregulated in ESRD but not much is known about the serum levels of VEGF in patients with ESRD. Published reports suggest that elevated levels of VEGF may be protective to the kidney during periods of acute injury and may maintain local glomerular function. Impaired production of VEGF may lead to proteinuria, hypertension, and thrombotic microangiopathy. However, its role in chronic kidney disease or ESRD remains undefined. In our study, we analyzed blood samples of 52 patients with ESRD on stable hemodialysis regimen and measured predialysis serum levels of VEGF and compared these with blood samples obtained from 50 healthy volunteers in order to study differences between baseline levels of VEGF and also attempted to determine its role in ESRD-related cardiovascular mortality.