Electrical stimulation affects the deposition of extracellular matrices and cellular differentiation. Type I collagen is one of the most abundant extracellular matrix proteins; however, not much is known about the effects of electrical stimulation on collagen type I deposition in C2C12 cells. Thus, we studied the effects of electrical voltage and stimulation frequency in 3D cultured C2C12 muscle cells in terms of metabolic activity, type I collagen deposition and cell morphology. Electrically excitable C2C12 muscle cells were seeded in collagen scaffolds and stimulated with rectangular signals of voltage (2, 5, 7 V) and frequency (1, 2 Hz), using parallel carbon electrodes spaced 1 cm apart. Metabolic activity was quantified by the glucose: lactate concentration ratio in the medium. Apoptotic activity was assessed by TUNEL staining and changes in collagen deposition were identified by immunohistology. The ultrastructure of the tissue was examined by TEM. Glucose and lactate analysis indicated that all groups had similar metabolic activity. TUNEL stain showed no significant difference in apoptotic damage induced by electrical stimulation compared to the control. Samples stimulated at 2 Hz exhibited reduced collagen deposition compared to the control and 1 Hz stimulated samples. Muscle-protein marker desmin was highly expressed in constructs stimulated with 1 Hz/5 V sample. TEM revealed that the stimulated samples developed highly organized sarcomeres, which coincided with improved contractile properties in the 1 Hz/5 V-and 2 Hz/5 Vstimulated groups. Our data implicate that a specific electrical frequency may modulate type I collagen accumulation and a specific voltage may affect the differentiation of muscle sarcomeres in excitable cells.

Background: Routine esophagogastroduodenoscopy (EGD) prior to bariatric surgery has not been consistently shown to change the management of the patient. A study was performed to estimate the proportion of patients undergoing bariatric surgery evaluation who had abnormal findings on preoperative EGD that resulted in alteration of management and, second, to evaluate potential risk factors for occurrence of abnormal findings on the EGD. Methods: An observational, retrospective study in which all 232 patients who were cleared to undergo bariatric surgery and who underwent preoperative EGD between 2006 and 2013 were included at a single tertiary dedicated bariatric center for weight loss management. Abnormal findings on screening EGD and medical or surgical management alteration based on the EGD findings were reviewed. Results: Abnormal findings on screening EGD were found in 143 patients (61.6%). Thirty-five patients had medical management altered (15.1%), while four patients (1.7%) had surgical management altered. Being aged > 55 years and the presence of gastroesophageal reflux disease were associated with occurrence of an abnormal finding on screening EGD. Conclusions: While abnormalities on preoperative EGD are often found in patients undergoing bariatric surgery evaluation, rarely do the findings change surgical management. Alternative methods for screening for common GI conditions should be considered in appropriate patients.

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