Evaluation of oesophageal mucosa integrity by the intraluminal impedance technique.

BACKGROUND: Oesophageal intraluminal impedance is currently used for assessment of reflux in gastro-oesophageal reflux disease (GORD). Oesophageal mucosa integrity may have a key role in heartburn perception in non-erosive reflux disease (NERD). Severe erosive oesophagitis is associated with low impedance baseline. We hypothesised that impedance baseline measurements could be used to evaluate changes in oesophageal mucosa integrity in man. METHODS: We measured oesophageal impedance baseline before, during and after acid perfusion in rabbits and healthy subjects. Transepithelial resistance (TER) was determined and dilated intercellular spaces (DIS) were assessed in isolated rabbit oesophageal mucosa. Impedance baseline was measured retrospectively at different levels of the oesophagus in impedance-pH recordings from asymptomatic volunteers and patients with GORD. RESULTS: In healthy subjects and rabbits, impedance baseline dropped dramatically during perfusion of control solution (pH 7.2) but after perfusion, impedance recovered. In rabbits, after perfusion with saline pH 1.5 and 1.0 impedance values remained a 39.1 ± 7.0% and 63.9 ± 6.5% (p < 0.05) lower respectively. There was a positive correlation between in vivo basal impedance and in vitro TER values (r = 0.72, p = 0.0021). Tissue showed no erosions but both acidic solutions induced DIS. In healthy subjects, after perfusion with saline pH 2.0 and 1.0 the impedance baseline remained lower a 21.9 ± 6.5% and 52.7 ± 5.0%, (p < 0.0001) respectively. Patients with GORD have a lower impedance baseline than healthy volunteers at the distal oesophagus. CONCLUSIONS: Impedance baseline measurements might be used to evaluate the status of the oesophageal mucosa and to study the role of the impaired mucosal integrity in acid-induced heartburn in healthy volunteers and in patients with GORD.

Effects of Multidirectional Vibrations Delivered in a Horizontal Position (Andullation®) on Blood Microcirculation in Laboratory Animals: A Preliminary Study.

BACKGROUND A whole-body vibration technique delivered in a horizontal position through a massage mattress was introduced in 2007. The present study analyzed the effects of different exposure periods to these vibrations on microcirculation of mice. MATERIAL AND METHODS Different periods of vibrations (30Hz) were locally delivered in a horizontal position on the external abdominal skin in 3 randomized groups of mice (N=42). The 3 groups receiving vibrations were compared to an untreated control group (N=14). The 3 experimental groups received 3, 6, and 10 min of vibrations. The in vivo measurement of the arterial and venous diameters was done before and after each vibration period. RESULTS Average venous diameters (µm) after 6 to 10 min of vibrations were significantly increased (7% and 12%, p values 0.026 and 0.013, respectively), but 3 min did not significantly change average venous diameters. Arterial diameters (µm) did not significantly vary after 3, 6, and 10 min. In the control group, variations of arterial and venous diameters during 10 min were not significant. CONCLUSIONS This study shows a vasodilatory effect of low-frequency vibrations. The hypothesis of local cutaneous blood flow increase is retained. A phenomenon of shear stress of the endothelium induced by skin massage generates this local venous vasodilation and blood flow increase.

Anatomical Effects of Axillary Nodes Dissection on Rat Lymphatic System Model: Indocyanine Green Mapping and Dissection.

BACKGROUND: Axillary nodes dissection (AND) is an important risk factor for the appearance of breast cancer-related lymphedema (BCRL). The anatomy and pathophysiology leading to the development of BCRL after AND are not completely understood. Despite the existence of lymphedema models after AND, none of them were able to create lymphedemas without additional chemical inflammatory drugs or auxiliary physical techniques (radiotherapy). In this study, we aimed to describe the anatomical changes of AND on a rat's front leg before and after a new surgery technique. METHODS AND RESULTS: AND was performed on seven Wistar rats with a new, posterior surgical approach. Indocyanine green mapping was done before and after surgery to detect "normal and secondary superficial lymphatic pathways" of the operated rat's front legs. Twelve months after surgery, dissections were performed. Subcutaneous blue dye injection of the hand was used to observe superficial and deep lymphatic pathways. Postsurgery, an acute edema of arm and shoulder appeared and persisted for 14-21 days. However, none of the rats showed a chronic secondary lymphedema. In two cases, seromas also appeared. All rats showed substitution functional lymphatic pathways as perforating lymph vessels around the surgical sites. CONCLUSION: This is the first description of perforating lymph vessels as lymphatic substitution pathways after AND on rats. These results help to understand why a chronic secondary lymphedema could not be created in rats after AND without additional chemical or physical interventions.