Leukocytes In Microcirculation Research Articles

The rolling leukocytes in the sublingual microcirculation during major liver resection: a new potential parameter for the monitoring of the inflammatory status?

Introduction: Systemic inflammatory response is a complication that occurs frequently in major liver resection patients. The surgical trauma and ischemia reperfusion injury due to the Pringle manoeuvre are the most important factors for triggering the inflammatory system. Aim of this study is to show the activation of the leukocytes in the microcirculation during surgery in order to introduce a new potential parameter; the rolling leukocytes. Methods: In this prospective observational study videos of the sublingual microcirculation were recorded using Cytocam, a handheld microscope which uses incident dark-field imaging technique. Two time points are measured, the baseline (T0) after induction of anesthesia, and the second time point (T1) at the end of the surgery. 14 patients were recruited, 12 are included, after undergoing evaluation using quality criteria in order to identify at least one post capillary venule (PCV) where focus is primarily important. Three clips for each time point with duration of 4 seconds (25 frames/sec) in different spots are captured. Identifying a PCV to count the activated leukocytes: sticking and rolling leukocytes in the wall of the PCV. Results: The count of the activated leukocytes from T0 (6.2±1.7 (L/PCV/4s)) to T1 (15.6±0.9 (L/PCV/4s)) increased significantly (P=< 0.0001). The count of the systemic leukocyte (8.2 ± 0.9 (x109/l)) and after (10.9 ± 1.4 (x109/l)) the surgery also increased significantly (p=0.0002). Conclusions: The leukocytes in the micro- and macrocirculation both increased. Monitoring the microcirculatory rolling leukocytes directly at the bedside can potentially assess the inflammatory status of the surgical patient.

Dietary Supplementation with Omega-3-PUFA-Rich Fish Oil Reduces Signs of Food Allergy in Ovalbumin-Sensitized Mice

We investigated the effect of dietary supplementation with n-3 PUFA (fish oil source) in an experimental model of food allergy. Mice were sensitized (allergic group) or not (nonallergic group) with OVA and were fed with OVA diet to induce allergy signals. Mice were fed with regular diet in which 7% of lipid content was provided by soybean (5% of n-3 PUFA) or fish (25% of n-3 PUFA) oil. Allergic group mice had increased serum levels of antiovalbumin IgE and IgG1 and changes in small intestine, characterized by an increased edema, number of rolling leukocytes in microcirculation, eosinophil infiltration, mucus production, and Paneth cell degranulation, in comparison to non-allergic group. All these inflammatory parameters were reduced in mice fed high-n-3-PUFA diet. Our data together suggest that diet supplementation with n-3 PUFA from fish oil may consist of a valid adjuvant in food allergy treatment.

In Vivo Evaluation of Leukocyte Dynamics in the Retinal and Choroidal Circulation

We have developed a new method to visualize leukocytes and evaluate their kinetics in the chorioretinal microcirculation of the living eyes. Nuclear staining dyes and a scanning laser ophthalmoscope were used to image leukocytes in the fundus. Acridine orange was used to visualize leukocytes in the retinal microcirculation. For imaging leukocytes in the choroid, indocyanine green was injected intravenously. Dynamics of leukocytes in the capillaries of the retina and choroid were quantitatively estimated in monkeys and rats. This method also allowed evaluation of leukocyte-endothelial interactions, such as rolling or firm adhesion, in vivo. Acridine orange leukocyte fluography was used to study leukocyte dynamics in the following experimentally induced microcirculatory disturbances of the retina: (1) interferon-associated retinopathy, (2) ischemia-reperfusion injury of the retina, and (3) experimental diabetes mellitus. (1) Interferon-associated retinopathy Systemic administration of interferon alpha enhanced leukocyte-endothelial interactions in the retina, which resulted in leukocyte rolling and entrapment in the retinal capillary beds. Leukocyte accumulation was also detected in the lung. The entrapment or accumulation of leukocytes in the microcirculation was inhibited by simultaneous administration of corticosteroids or other agents. These results suggested that leukocytes play a major role in the development of adverse effects of interferon, such as retinopathy or interstitial pneumonia. (2) Ischemia-reperfusion injury of the retina During reperfusion period after transient (60 min) retinal ischemia by optic nerve ligation, the rolling of leukocytes in the retinal veins was prominent and numerous leukocytes were trapped in the retinal capillaries. The number of rolling leukocytes was at a maximum 12 hours after reperfusion. Leukocyte entrapment peaked at 24 hours after reperfusion. By blocking adhesion molecules on the vascular endothelium, these leukocyte-endothelial interactions were effectively inhibited. Postischemic retinal atrophy was also inhibited by blocking adhesion molecules. These results suggested that leukocytes may be major players in the pathophysiology of ischemia reperfusion injury of the retina. (3) Experimental diabetes mellitus Leukocyte dynamics in the retina were studied in streptozotocin-induced diabetes and spontaneous diabetes (OLETF rats). In both diabetic models, leukocyte entrapment in the retinal capillaries was increased even in the early stages of diabetes. Fluorescein angiography revealed that trapped leukocytes disturbed the regional capillary blood flow in the downstream. Enhanced expression of adhesion molecules was observed in the capillary endothelium of the retina in the diabetic rats. Leukocyte entrapment in the retinal capillaries might cause microvascular occlusions and dysfunction, in turn causing diabetic retinopathy.

Studies on the flow and distribution of leukocytes in mesentery microcirculation of rats.

AIM:To study the effect of leukocyte-endothelium interaction (LEI) on the flow and distribution of leukocytes in microcirculation under physiological condition.METHODS:A microcirculation image multiple parameter computer analysis system (MIMPCAS) was used to study the flow and distribution of leukocytes in mesentery microcirculation of rats in vivo.RESULTS:The difference of visible leukocyte flux (VLF) was as high as 131 times in the arterioles and venules with similar diameter and blood velocity. The visible leukocytes rolled along the blood vessel wall as a jerky movement. The frequency distribution of the visible leukocyte velocity (VLV) showed a two peak curve. The low peak value was on 10&mgr;m/s-15&mgr;m/s while the high peak fell between 25&mgr;m/s-30&mgr;m/s. With the increase of diameter of venules, VLF increased while the VLV remained at the same level. With the increase of RBC velocity, VLV trends to elevate and VLF to fall down.CONCLUSION:The results herein might provide a basic theory for the study on the mechanism of LEI under physiological condition and novel methods for the prevention and treatment of high LEI in many pathological processes.

Effect of rat CINC/gro, a member of the interleukin-8 family, on leukocytes in microcirculation of the rat mesentery

Rat cytokine-induced neutrophil chemoattractant (CINC) is a member of the IL-8 family, and its human counterpart is gro/MGSA but not IL-8. We ascertained that chemically synthesized CINC was comparable to native CINC/gro with regard to chemotactic activity for rat neutrophils and studied the effect of synthesized CINC/gro on circulating leukocytes in microvascular vessels of rat mesentery. Exposure of rat mesentery to 10 −8 M authentic CINC/gro induced neutrophil adherence to and extravasation from postcapillary venules (PCVs) but not from capillaries or arterioles. CINC/gro concentrations as low as 10 −10 M were effective in causing neutrophil adherence. Neutrophils adhered to thin PCVs (mean diameter, ∼25 μm) after exposure to CINC/gro for 15 min. The mean diameters of the PCV with adherence of neutrophils after exposure to CINC/gro for 30 and 60 min were 37 and 43 μm, respectively. The diameters of PCV with extravasation of neutrophils also increased in a time-dependent manner. The starting position of adherence of neutrophils was ∼25–50 μm away from the upper junction of two vessels and remained virtually unchanged during exposure to CINC/gro for 60 min. However, the distance from the start to the end of neutrophil adherence increased in a time-dependent manner. The effect of CINC/gro on adherence and extravasation of leukocytes was neutrophil specific since other leukocytes such as lymphocytes and monocytes were not identified among the adherent and extravasated leukocytes.