Altered kinetics of circulating progenitor cells in cardiopulmonary bypass (CPB) associated vasoplegic patients: A pilot study.

Vasoplegia observed post cardiopulmonary bypass (CPB) is associated with substantial morbidity, multiple organ failure and mortality. Circulating counts of hematopoietic stem cells (HSCs) and endothelial progenitor cells (EPC) are potential markers of neo-vascularization and vascular repair. However, the significance of changes in the circulating levels of these progenitors in perioperative CPB, and their association with post-CPB vasoplegia, are currently unexplored. We enumerated HSC and EPC counts, via flow cytometry, at different time-points during CPB in 19 individuals who underwent elective cardiac surgery. These 19 individuals were categorized into two groups based on severity of post-operative vasoplegia, a clinically insignificant vasoplegic Group 1 (G1) and a clinically significant vasoplegic Group 2 (G2). Differential changes in progenitor cell counts during different stages of surgery were compared across these two groups. Machine-learning classifiers (logistic regression and gradient boosting) were employed to determine if differential changes in progenitor counts could aid the classification of individuals into these groups. Enumerating progenitor cells revealed an early and significant increase in the circulating counts of CD34+ and CD34+CD133+ hematopoietic stem cells (HSC) in G1 individuals, while these counts were attenuated in G2 individuals. Additionally, EPCs (CD34+VEGFR2+) were lower in G2 individuals compared to G1. Gradient boosting outperformed logistic regression in assessing the vasoplegia grouping based on the fold change in circulating CD 34+ levels. Our findings indicate that a lack of early response of CD34+ cells and CD34+CD133+ HSCs might serve as an early marker for development of clinically significant vasoplegia after CPB.

Hyperinsulinemia promotes endothelial inflammation via increased expression and release of Angiopoietin-2.

BACKGROUND AND AIMS: Angiopoietin-2 (ANG-2) mediates endothelial inflammation to initiate atherosclerosis and angiogenesis. Here we determined the serum levels of ANG-2 in hyperinsulinemic subjects and whether insulin increases its expression and release. METHODS: Healthy male subjects were recruited from the D-CLIP and CURES studies and, based on their fasting insulin levels, were classified as normoinsulinemic (n = 228) and hyperinsulinemic (n = 32). Serum proteins were estimated by ELISA. Endothelial inflammation was scored as the number of THP-1 monocytes adhered to HUVEC monolayer. Gene expression was determined with promoter reporter assays and semi-quantitative RT-PCR. Western blotting was used to assess changes in protein expression and activation. Immunofluorescence imaging and ChIP assay were used for nuclear localization and promoter binding studies, respectively. RESULTS: ANG-2 and sTIE2 levels were higher in hyperinsulinemic subjects. Hyperinsulinemic serum elicited endothelial inflammation, which was abrogated by an ANG-2 blocker antibody. Insulin (100 nM) increased mRNA and protein expression of ANG-2, and its release from HUVECs. It induced activation of p38 MAPK and an increase in protein levels and nuclear localization of cFOS. Binding of cFOS to the -640 to -494 promoter region mediated insulin dependent ANG-2 transcription. p38 MAPK inhibitor (25 µM) blocked insulin-induced nuclear localization of cFOS, expression of ANG-2 and ICAM-1, and release of ANG-2 into the culture medium. Spent medium collected from insulin treated cells enhanced endothelial inflammation, which was lost upon ANG-2 knockdown as well as upon p38 MAPK inhibition. CONCLUSIONS: ANG-2 levels are high in hyperinsulinemic subjects and insulin induces expression and release of ANG-2 from HUVECs through p38 MAPK-cFOS pathway to elicit endothelial inflammation.

Prevalence and implications of thyroid related embryological remnants: A prospective study of 1118 total thyroidectomies.

CONTEXT: Modern thyroid surgery has undergone a paradigm shift from subtotal thyroidectomy to an extended total thyroidectomy (TT) even for benign disorders. This entails removal of all embryological remnants even in benign disorders. AIMS: To study the prevalence of various embryological remnants of the thyroid and surgical utility and implications in preventing complications. SETTINGS AND DESIGN: Retrospective study of total thyroidectomies done by a single endocrine surgeon by standardized technique. METHODS AND MATERIAL: A detailed search of all embryological rests including Pyramidal tract (PT), Tubercle of Zuckerkandl (TZ), and Thyro-thymic thyroid rests (TTR) were done in 1118 patients undergoing TT over 6 years. The cases with and without TTR were divided as Group A and B, respectively. Their prevalence and impact on parathyroid preservation and other clinical parameters were analysed. STATISTICAL ANALYSIS USED: Descriptive analyses. RESULTS: Out of the 1118 TT cases, TTR was seen in 230 (20.57%) cases, TZ in 598 (53.48%), cases and PT in 641 (57.33%) cases. Among group-A (n = 230), 213 had unilateral and 17 had bilateral TTR with 51 (22.17%) having retrosternal extension. Compressive symptoms, presence of TZ and PT were also significantly higher in group A. On follow up the incidence of temporary hypoparathyroidism was significantly higher in group-A, where as permanent hypoparathyroidism, temporary and permanent vocal cord palsy were comparable between the two study groups. CONCLUSIONS: Embryological remnants related to thyroid are not uncommonly encountered during total thyroidectomy. A thorough search and complete removal is crucial for the successful outcome of the procedure.

Quantification of photocatalytic oxygenation of human blood.

Photocatalytic oxygenation of human blood is an emerging concept based on the principle of photocatalytic splitting of water into oxygen and hydrogen. This communication reports: (i) a design of a photocatalytic cell (PC) that separates the blood from UV (incident) radiation source, (ii) a pH, temperature and flow controlled circuit designed for quantifying the oxygenation of human blood by photocatalysis and (iii) measuring the current efficacy of ITO/TiO2 nano thin films in oxygenating human blood in a dynamic circuit in real time. The average increase in oxygen saturation was around 5% above baseline compared to control (p<0.0005). We believe this is one of the first attempts to quantify photocatalytic oxygenation of human blood under controlled conditions.

Glucose-induced increase in circulating progenitor cells is blunted in polycystic amenorrhoeic subjects.

BACKGROUND: Glucose-induced kinetics of bone marrow-derived stem cells in healthy females is presently unknown. The objectives of this study were to determine whether circulating levels of CD133(+), CD34(+) and CD133(+)CD34(+) cells increase in response to glucose load in healthy females and whether the kinetics is altered in amenorrhoeic women. The other objective of the work was to compare the endothelial differentiation potential of peripheral blood-derived endothelial progenitor cells (EPCs) from healthy versus amenorrhoeic women. METHODS: In this case-control study, 44 amenorrhoeic subjects and 36 age-matched females with no menstrual disturbance were recruited at Apollo Hospitals, a Tertiary health care center in Chennai, India. Circulating bone marrow-derived stem cells were measured by two color direct flow cytometry. Cultured progenitor cells were characterized at Day 7 and 14 for expression of endothelial markers and production of nitric oxide (NO) via immunofluoroscence. RESULTS: The amenorrhoeic subjects were insulin resistant with homeostatic model of assessment of insulin resistance values of 3.33 ± 0.3 versus 1.75 ± 0.148 observed for controls (P< 0.0001). Among the amenorrhoeic subjects, 38 subjects had polycystic ovaries with no signs of hyperandrogenism. Fasting levels of CD133(+), CD34(+) and CD133(+)CD34(+) cells were reduced in amenorrhoeic subjects (P< 0.001). There was a 1.5 to 2-fold increase in the circulating levels of these cells in response to 75 g oral glucose challenge at 1 and 2 h post-load conditions in controls, which was significantly blunted for CD133(+) (P< 0.001) and CD133(+)CD34(+) (P< 0.001) cells in amenorrhoeic subjects. A positive correlation was observed between estrogen and fasting CD133(+) (r= 0.205, P= 0.070), CD34(+) (r= 0.249, P= 0.027) and CD133(+)CD34(+) (r= 0.217, P= 0.055) cell counts. Additionally, fasting counts for CD34(+) and CD133(+)CD34(+) cells positively correlated with FSH and inversely correlated with LH and C-peptide in the polycystic group. Cultured cells from polycystic subjects exhibited reduced adherence to fibronectin and expressed lower levels of endothelial nitric-oxide synthase and NO. CONCLUSIONS: Oral glucose-induced increase in circulating numbers of CD133(+) and CD133(+)CD34(+) cells and endothelial differentiation potential of peripheral blood-derived EPCs is attenuated in insulin resistant amenorrhoeic subjects.

In vivo arginine production and intravascular nitric oxide synthesis in hypotensive sepsis.

BACKGROUND: Arginine is important in the response to infections and is a precursor for the synthesis of the vasodilator nitric oxide (NO). Low plasma arginine is correlated with a worse prognosis in patients with sepsis, and increased NO has been implicated in the hypotension of sepsis. Data on in vivo arginine and NO kinetics are lacking in hypotensive septic adults. OBJECTIVE: We aimed to measure in vivo arginine production and the intravascular NO synthesis rate in hypotensive septic patients. DESIGN: Arginine flux and the fractional and absolute synthesis rates of plasma NO were measured in fasted healthy (n = 10) and hypotensive septic (n = 6) adults by using a 6-h constant infusion of [15N2-guanidino]arginine. Urinary excretion of the NO metabolites nitrite and nitrate (NOx) and plasma concentrations of NOx, arginine, and creatinine were also measured. RESULTS: All patients had hyperdynamic septic shock and impaired renal function. Compared with the control subjects, the patients had slower arginine flux (99 +/- 8 compared with 50 +/- 7 micromol x kg(-1) x h(-1); P < 0.01), lower plasma arginine concentrations (75 +/- 8 compared with 40 +/- 11 micromol/L; P < 0.01), higher plasma NOx concentrations (30 +/- 4 compared with 65 +/- 1.8 micromol/L), and a slower fractional synthesis rate of NOx. There was no significant difference in the absolute synthesis rate of NOx between groups. In patients with sepsis, the plasma NOx concentration correlated with the glomerular filtration rate and plasma creatinine but not with mean arterial pressure. CONCLUSIONS: Patients with septic shock have a shortage in the availability of arginine associated with a slower production. Impaired renal excretion of NOx is a contributor to the high plasma NOx in these patients.