Sonographic Evaluation of Internal Jugular Vein Diameter and Cross-sectional Area Measurements in Correlation with Left Ventricular End Diastolic Area as a Tool for Perioperative Assessment of Volume Status in Pediatric Patients Undergoing Cardiac Surgery.

AIM: The aim of this study is to compare the ultrasound estimation of the cross-sectional area (CSA) and diameter of internal jugular vein (IJV) with left ventricular end diastolic area (LVEDA) for the assessment of intravascular volume in pediatric patients during cardiac surgery. PATIENTS AND METHODS: The CSA and diameter of the left IJV were defined, using ultrasound machine, and compared with LVEDA, estimated by transesophageal echo, in four times intervals (immediately after induction [T1], before the start of cardiopulmonary bypass [CPB] [T2], immediately after weaning of CPB [T3], and at the end of surgery before transfer to the Intensive Care Unit [T4]) as a tool for intravascular volume assessment in 16 pediatric patients undergoing cardiac surgery. RESULTS: There was a poor correlation between IJV CSA and diameter with LVEDA. r values were 0.158, 0.265, 0.449, and 0.201 at the four time intervals (T1, T2, T3, and T4), respectively. CONCLUSION: Estimation of the CSA and diameter of the left IJV using ultrasound is not reliable and cannot be used alone to decide further management.

Local renin-angiotensin system regulates the differentiation of mesenchymal stem cells into insulin-producing cells through angiotensin type 2 receptor.

Differentiation of stem cells into insulin-producing cells (IPCs) suitable for therapeutic transplantation offers a desperately needed approach for the diabetic patients. Elucidation of the molecular mechanisms during the differentiation of mesenchymal stem cells (MSCs) into IPCs assists the successful production of IPCs and provides an important insight into the improvement of the role of MSCs as a therapeutic tool for diabetes mellitus (DM). The present study aimed to investigate the role of local renin-angiotensin system (RAS) on MSCs differentiation into IPCs by measuring the expression of local RAS in MSCs during the differentiation into IPCs and assessing the effect of angiotensin type 1 receptor (AT1R) blocker and angiotensin type 2 receptor (AT2R) blocker on the differentiation process. Our data showed that the differentiation of MSCs into IPCs was associated with an increase in cellular angiotensinogen, angiotensin-converting enzyme (ACE), renin, and AT2R expression and undetectable expression of AT1R. The net effect was an increase in cellular angiotensin II (Ang II) during the differentiation process. AT1R blockade allowed the differentiation of MSCs into IPCs, whereas AT2R blockade alone and blockade of both AT1R and AT2R inhibited the differentiation of MSCs into IPCs. Our data demonstrated an important role of local RAS in the regulation of MSCs differentiation into IPCs and that Ang II mainly orchestrates this role through AT2R activation.