Morphologic Mapping of the Sublingual Microcirculation in Healthy Volunteers

PURPOSE Monitoring the sublingual and oral microcirculation (SM-OM) using hand-held vital microscopes (HVMs) has provided valuable insight into the (patho)physiology of diseases. However, the microvascular anatomy in a healthy population has not been adequately described yet. METHODS Incident dark field-based HVM imaging was used to visualize the SM-OM. First, the SM was divided into four different fields; Field-a (between incisors-lingua), Field-b (between the canine-first premolar-lingua), Field-c (between the first-second premolar-lingua), Field-d (between the second molar-wisdom teeth-lingua). Second, we investigated the buccal area, lower and upper lip. Total/functional vessel density (TVD/FCD), focus depth (FD), small vessel mean diameters (SVMDs), and capillary tortuosity score (CTS) were compared between the areas. RESULTS Fifteen volunteers with a mean age of 29 ± 6 years were enrolled. No statistical difference was found between the sublingual fields in terms of TVD (p = 0.30), FCD (p = 0.38), and FD (p = 0.09). SVMD was similar in Field-a, Field-b, and Field-c (p = 0.20-0.30), and larger in Field-d (p < 0.01, p = 0.015). The CTS of the buccal area was higher than in the lips. CONCLUSION The sublingual area has a homogenous distribution in TVD, FCD, FD, and SVMD. This study can be a description of the normal microvascular anatomy for future researches regarding microcirculatory assessment

Leukocyte-Endothelium Interaction in the Sublingual Microcirculation of Coronary Artery Bypass Grafting Patients

Objective: The aim of this study was to apply an innovative methodology to incident dark-field (IDF) imaging in coronary artery bypass grafting (CABG) patients for the identification and quantification of rolling leukocytes along the sublingual microcirculatory endothelium. Methods: This study was a post hoc analysis of a prospective study that evaluated the perioperative course of the sublingual microcirculation in CABG patients. Video images were captured using IDF imaging following the induction of anesthesia (T-0) and cardiopulmonary bypass (CPB) (T-1) in 10 patients. Rolling leukocytes were identified and quantified using frame averaging, which is a technique that was developed for correctly identifying leukocytes. Results: The number of rolling leukocytes increased significantly from T-0 (7.5 {[}6.4-9.1] leukocytes/capillary-postcapillary venule/4 s) to T-1 (14.8 {[}13.2-15.5] leukocytes/capillary-postcapillary venule/4 s) (p < 0.0001). A significant increase in systemic leukocyte count was also detected from 7.4 +/- 0.9 x 10(9)/L (preoperative) to 12.4 +/- 4.4 x 10(9)/L (postoperative) (p < 0.01). Conclusion: The ability to directly visualize leukocyte-endothelium interaction using IDF imaging facilitates the diagnosis of a systemic inflammatory response after CPB via the identification of rolling leukocytes. Integration of the frame averaging algorithm into the software of handheld vital microscopes may enable the use of microcirculatory leukocyte count as a real-time parameter at the bedside.1JAN8-155

Experimental and numerical investigation of RC beams strengthened with CFRP composites

U ovom radu naglasak je na pojačanju armiranobetonskih greda nedovoljnog posmičnog kapaciteta uporabom polimera armiranih ugljičnim vlaknima (Carbon Fibre Reinforced Polymer - CFRP) i inovativnih načina sidrenja. Predlaže se, također, i inovativna metoda za pojačanje greda na kontaktu dviju konstrukcija. Rezultati ispitivanja pokazali su da se dodavanjem CFRP-a poboljšava ponašanje greda. Nelinearni proračun proveden je primjenom metode konačnih elemenata (FE) te američkih i talijanskih smjernica s ciljem procijene teoretskog kapaciteta greda. Zaključak je da se predložene metode mogu pouzdano primjenjivati, a projektiranje armiranobetonskih greda pojačanih na taj način može se provesti uz pomoć jednostavnih metoda proračuna.This study aims to strengthen reinforced concrete (RC) beams having insufficient shear capacity using Carbon Fibre Reinforced Polymer (CFRP) members and innovative anchorages. An innovative method is also proposed for strengthening beams in interaction site of adjacent structures. Test results show that the behaviour of beams has been improved with CFRP elements. The nonlinear finite element (FE) method; as well as American and Italian guidelines; are used to estimate theoretical capacity of the beams. Test results are compared with theoretical results. It can be concluded that proposed methods can be used reliably; and that the design of RC beams strengthened with these methods can be performed by design engineers based on simple calculations

Identifying a sublingual triangle as the ideal site for assessment of sublingual microcirculation

The sublingual mucosa is a commonly used intraoral location for identifying microcirculatory alterations using handheld vital microscopes (HVMs). The anatomic description of the sublingual cave and its related training have not been adequately introduced. The aim of this study was to introduce anatomy guided sublingual microcirculatory assessment. Measurements were acquired from the floor of the mouth using incident dark-field (IDF) imaging before (T0) and after (T1) sublingual cave anatomy instructed training. Instructions consists of examining a specific region of interested identified through observable anatomical structures adjacent and bilaterally to the lingual frenulum which is next to the sublingual papilla. The anatomical location called the sublingual triangle, was identified as stationed between the lingual frenulum, the sublingual fold and ventrally to the tongue. Small, large, and total vessel density datasets (SVD, LVD and TVD respectively) obtained by non-instructed and instructed measurements (NIN (T0) and IM (T1) respectively) were compared. Microvascular structures were analyzed, and the presence of salivary duct-related microcirculation was identified. A total of 72 video clips were used for analysis in which TVD, but not LVD and SVD, was higher in IM compared to NIM (NIM vs. IM, 25 ± 2 vs. 27 ± 3 mm/mm$^{2}$ (p = 0.044), LVD NIM vs. IM: 7 ± 1 vs. 8 ± 1mm/mm$^{2}$ (p = 0.092), SVD NIM vs. IM: 18 ± 2 vs. 20 ± 3 mm/mm$^{2}$ (p = 0.103)). IM resulted in microcirculatory assessments which included morphological properties such as capillaries, venules and arterioles, without salivary duct-associated microcirculation. The sublingual triangle identified in this study showed consistent network-based microcirculation, without interference from microcirculation associated with specialized anatomic structures. These findings suggest that the sublingual triangle, an anatomy guided location, yielded sublingual based measurements that conforms with international guidelines. IM showed higher TVD values, and future studies are needed with larger sample sizes to prove differences in microcirculatory parameters

The effect of CO₂ laser therapy on vaginal microcirculatory parameters in an animal model for genitourinary syndrome of menopause

Background: Vaginal laser therapy for the treatment of genitourinary syndrome of menopause (GSM) has been introduced to the market with limited (pre)clinical and experimental evidence supporting its efficacy. It is suggested that vaginal laser therapy increases epithelial thickness and improves vascularization, but the underlying biological working mechanism has not been substantiated yet. Objective: To evaluate the effects of CO2 laser therapy on vaginal atrophy using noninvasive incident dark field (IDF) imaging in a large animal model for GSM. Design, Setting, and Participants: An animal study was conducted between 2018 and 2019 and included 25 Dohne Merino ewes, of which 20 underwent bilateral ovariectomy (OVX) to induce iatrogenic menopause, and 5 did not. The total study duration was 10 months. Interventions: Five months after OVX, ovariectomized ewes received monthly applications of CO2 laser (n = 7), vaginal estrogen (n = 7), or no treatment (n = 6) for 3 months. IDF imaging was performed monthly in all animals. Outcome Measurements and Statistical Analysis: The primary outcome was the proportion of image sequences containing capillary loops (angioarchitecture). Secondary outcomes included focal depth (epithelial thickness), and quantitative measures of vessel density and perfusion. Treatment effects were evaluated using ANCOVA and binary logistic regression. Results and Limitations: Compared to OVX-only, ewes treated with estrogen demonstrated a higher capillary loops proportion (4% vs. 75%, p &lt; 0.01), and higher focal depth (60 (IQR 60–80) vs. 80 (IQR 80–80) p &lt; 0.05). CO2 laser therapy did not change microcirculatory parameters. As the ewes' vaginal epithelium is thinner than that of humans, it may demand different laser settings. Conclusions: In a large animal model for GSM, CO2 laser therapy does not affect microcirculatory outcomes related to GSM, whereas vaginal estrogen treatment does. Until more homogeneous and objective evidence about its efficacy is available, CO2 laser therapy should not be adopted into widespread practice for treating GSM.</p

The effect of CO2_{2} laser therapy on vaginal microcirculatory parameters in an animal model for genitourinary syndrome of menopause

Background: Vaginal laser therapy for the treatment of genitourinary syndrome of menopause (GSM) has been introduced to the market with limited (pre)clinical and experimental evidence supporting its efficacy. It is suggested that vaginal laser therapy increases epithelial thickness and improves vascularization, but the underlying biological working mechanism has not been substantiated yet. Objective: To evaluate the effects of CO$_{2}$ laser therapy on vaginal atrophy using noninvasive incident dark field (IDF) imaging in a large animal model for GSM. Design, Setting, and Participants: An animal study was conducted between 2018 and 2019 and included 25 Dohne Merino ewes, of which 20 underwent bilateral ovariectomy (OVX) to induce iatrogenic menopause, and 5 did not. The total study duration was 10 months.InterventionsFive months after OVX, ovariectomized ewes received monthly applications of CO$_{2}$ laser (n = 7), vaginal estrogen (n = 7), or no treatment (n = 6) for 3 months. IDF imaging was performed monthly in all animals. Outcome Measurements and Statistical Analysis: The primary outcome was the proportion of image sequences containing capillary loops (angioarchitecture). Secondary outcomes included focal depth (epithelial thickness), and quantitative measures of vessel density and perfusion. Treatment effects were evaluated using ANCOVA and binary logistic regression.Results and LimitationsCompared to OVX‐only, ewes treated with estrogen demonstrated a higher capillary loops proportion (4% vs. 75%, p < 0.01), and higher focal depth (60 (IQR 60–80) vs. 80 (IQR 80–80) p < 0.05). CO$_{2}$ laser therapy did not change microcirculatory parameters. As the ewes' vaginal epithelium is thinner than that of humans, it may demand different laser settings. Conclusions: In a large animal model for GSM, CO$_{2}$ laser therapy does not affect microcirculatory outcomes related to GSM, whereas vaginal estrogen treatment does. Until more homogeneous and objective evidence about its efficacy is available, CO$_{2}$ laser therapy should not be adopted into widespread practice for treating GSM

MicroTools enables automated quantification of capillary density and red blood cell velocity in handheld vital microscopy

Direct assessment of capillary perfusion has been prioritized in hemodynamic management of critically ill patients in addition to optimizing blood flow on the global scale. Sublingual handheld vital microscopy has enabled online acquisition of moving image sequences of the microcirculation, including the flow of individual red blood cells in the capillary network. However, due to inherent content complexity, manual image sequence analysis remained gold standard, introducing inter-observer variability and precluding real-time image analysis for clinical therapy guidance. Here we introduce an advanced computer vision algorithm for instantaneous analysis and quantification of morphometric and kinetic information related to capillary blood flow in the sublingual microcirculation. We evaluated this technique in a porcine model of septic shock and resuscitation and cardiac surgery patients. This development is of high clinical relevance because it enables implementation of point-of-care goal-directed resuscitation procedures based on correction of microcirculatory perfusion in critically ill and perioperative patients

Hemodilution causes glycocalyx shedding without affecting vascular endothelial barrier permeability in rats

Background The consequences of acute normovolemic hemodilution (ANH) following different types of fluids on the different components of the glycocalyx and on vascular barrier permeability (VBP) remain unknown. Aim The aim of the study was to investigate whether the microcirculatory disruption and glycocalyx shedding induced by ANH alters VBP and whether this is affected by the composition and volume of the resuscitation fluid. Materials and Methods Anesthetized Wistar albino rats (n=24) underwent stepwise ANH at hematocrit levels of 35%, 25%, 20%, and 15% induced by the exchange of blood with 6% balanced hydroxyethyl starch (1:1), balanced crystalloid (1:3), and normal saline (NS) (1:3). Glycocalyx-shed products were measured at each level of hemodilution. VBP was reflected in the decay of fluorescence dyes of different molecular size and their plasma retention ratios. Edema was assessed by measuring organ water content and muscle microcirculation by hand-held videomicroscopy. Results NS caused increased degradation of heparan sulfate and hyaluronan compared with the control group (P=0.003, P=0.004, respectively). Neither VBP nor tissue edema was affected by the fluid used. The total and perfused vessel densities within the microcirculation of muscle tissue decreased at hematocrit 15% in the balanced crystalloid (P=0.02) and NS groups only (P<0.0001, P=0.0003, respectively) compared with baseline. Conclusions Balanced colloid solution preserved the glycocalyx layer better than balanced and unbalanced crystalloid solutions while maintaining the microcirculatory function associated with an improved total intravascular volume. Among the fluids tested, NS caused the most microcirculatory alterations. While ANH caused the degradation of glycocalyx components regardless of fluid, it did not disrupt the vascular barrier as indicated by macromolecular leakage. Relevance for Patients The results of this study provide insight into the choice of fluid for optimal perioperative fluid management and the consequences of fluid type on the vascular barrier, glycocalyx, and microcirculation

Membrane fouling in thermophilic aerobic membrane distillation bioreactor treating hospital wastewater

In the membrane distillation bioreactor (MDBR) process, flux increases with increasing feed temperature, but the presence of microorganisms limits the feed temperature. Also, the accumulation of cells and other substances on the membrane surface can affect the efficiency of MDBR. In this study, hospital wastewater was treated by thermophilic activated sludge MDBR. In the MDBR, the initial flux was 7.87 L‧m−2·h−1 and the stable flux was 3.88 L‧m−2·h−1. The particle size, zeta potential and hydrophobicity of the activated sludge in MDBR were 2.25 µm, −14 mV and 24%, respectively. In addition, EPS (extracellular polymeric substances) and SMP (soluble microbial products), having a significant effect on membrane fouling, were determined to be 201.50 mg·L−1 and 669.35 mg·L−1 in MDBR, respectively. Contact angle, FTIR (Fourier transform infrared), SEM (scanning electron microscope) and EDX (energy dispersive X-ray spectroscopy) measurements were also made on a virgin membrane and used membrane. Analysis of EDX, SEM and F-TIR showed that the membrane fouling was caused by CaCO3 and EPS