Natural history of symptoms and prognostic information of the rapid drink challenge and solid bolus swallows in esophagogastric junction outflow obstruction defined by manometry.

BACKGROUND/INTRODUCTION: Esophagogastric junction outflow obstruction (EGJOO) is a condition characterized by poor relaxation of the lower esophageal sphincter (LES), which can manifest as dysphagia and chest pain. The best treatment of EGJOO is unknown as some patients improve without any specific therapy, whereas some patients undergo invasive therapy. Currently, prognostic factors are lacking. We aimed to assess the long-term prognosis and predictors of dysphagia and chest pain by the rapid drink challenge and solid bolus swallows in EGJOO. METHODS: We retrospectively assessed high-resolution esophageal manometries (HRM) performed at our center between 2015 and 2018. The patients completed a dysphagia and chest pain questionnaire a median of 34 months after the HRM/baseline assessment, including the Impaction dysphagia questionnaire-10 (IDQ-10) complemented with questions regarding chest pain and esophageal treatments. Symptoms were compared with HRM findings. RESULTS: In all, 980 HRMs were analyzed and 66 (6.5%) were identified as having HRM findings compatible with EGJOO. Of these, 27 patients with EGJOO (41%) completed the follow-up questionnaires and had no exclusion criteria, and 70% of these patients had dysphagia and 44% chest pain at least once a week. Dysphagia at follow-up was more common in patients with elevated integrated relaxation pressure (IRP) on all three HRM metrics (water swallows, solid bolus swallows, and rapid drink challenge) (p = 0.03, odds ratio: 8.4 (95% CI: 1.2-56.0)), but this was not seen for chest pain (p = 0.45). Abnormal motility patterns on rapid drink challenge or solid bolus swallows were not associated with dysphagia or chest pain at follow-up. CONCLUSIONS: Having a high IRP on three HRM metrics-water swallows, solid bolus swallows, and rapid drink challenge-is associated with a worse prognosis in patients with EGJOO and could potentially be used to select candidates suitable for invasive procedures.

Evaluation of Chemical Changes in Laboratory-Induced Colistin-Resistant Klebsiella pneumoniae.

This study evaluates the electrical potential and chemical alterations in laboratory-induced colistin-resistant Klebsiella pneumoniae, as compared to the susceptible strain using spectroscopic analyses. The minimal inhibitory concentration (MIC) of colistin, ζ-potential and chemical composition analysis of K. pneumoniae strains are determined. The results obtained for the K. pneumoniaeCol-R with induced high-level colistin resistance (MIC = 16.0 ± 0.0 mg/L) are compared with the K. pneumoniaeCol-S strain susceptible to colistin (MIC = 0.25 ± 0.0 mg/L). Fourier transform infrared (FTIR) and Raman spectroscopic studies revealed differences in bacterial cell wall structures and lipopolysaccharide (LPS) of K. pneumoniaeCol-R and K. pneumoniaeCol-S strains. In the beginning, we assumed that the obtained results could relate to a negative charge of the bacterial surface and different electrostatic interactions with cationic antibiotic molecules, reducing the affinity of colistin and leading to its lower penetration into K. pneumoniaeCol-R cell. However, no significant differences in the ζ-potential between the K. pneumoniaeCol-R and K. pneumoniaeCol-S strains are noticed. In conclusion, this mechanism is most probably associated with recognisable changes in the chemical composition of the K. pneumoniaeCol-R cell wall (especially in LPS) when compared to the susceptible strain.