Summary The budding yeast, Saccharomyces cerevisiae, has emerged as an archetype of eukaryotic cell biology. Here we show that S. cerevisiae is also a model for the evolution of cooperative behavior by revisiting flocculation, a self-adherence phenotype lacking in most laboratory strains. Expression of the gene FLO1 in the laboratory strain S288C restores flocculation, an altered physiological state, reminiscent of bacterial biofilms. Flocculation protects the FLO1-expressing cells from multiple stresses, including antimicrobials and ethanol. Furthermore, FLO1+ cells avoid exploitation by non-expressing flo1 cells by self/non-self recognition: FLO1+ cells preferentially stick to one another, regardless of genetic relatedness across the rest of the genome. Flocculation, therefore, is driven by one of a few known “green beard genes”, which direct cooperation towards other carriers of the same gene. Moreover, FLO1 is highly variable among strains both in expression and in sequence, suggesting that flocculation in S. cerevisiae is a dynamic, rapidly-evolving social trait.

Background Celiac disease (CD) is under-diagnosed in the United States, and factors related to the performance of endoscopy may be contributory. Aims to identify newly diagnosed patients with CD who had undergone a prior esophagogastroduodenoscopy (EGD) and examine factors contributing to the missed diagnosis. Methods We identified all patients age ≥18 years whose diagnosis of CD was made by endoscopy with biopsy at our institution (n=316), and searched the medical record for a prior EGD. We compared those patients with a prior EGD to those with without a prior EGD with regard to age at diagnosis and gender, and enumerated the indications for EGD. Results Of the 316 patients diagnosed by EGD with biopsy at our center, 17 (5%) had previously undergone EGD. During the prior non-diagnostic EGD, a duodenal biopsy was not performed in 59% of the patients, and ≥4 specimens (the recommended number) were submitted in only 29% of the patients. On the diagnostic EGD, ≥4 specimens were submitted in 94%. The mean age of diagnosis of those with missed/incident CD was 53.1 years, slightly older than those diagnosed with CD on their first EGD (46.8 years, p=0.11). Both groups were predominantly female (missed/incident CD: 65% vs. 66%, p=0.94). Conclusions Among 17 CD patients who had previously undergone a non-diagnostic EGD, nonperformance of duodenal biopsy during the prior EGD was the dominant feature. Routine performance of duodenal biopsy during EGD for the indications of dyspepsia and reflux may improve CD diagnosis rates.

Dysphagia is a common problem in the elderly population with an especially high prevalence in hospitalized and institutionalized patients. If inadequately addressed, dysphagia leads to significant morbidity and contributes to decreased quality of life. Dysphagia can be categorized as emanating from either an oropharyngeal or esophageal process. A disproportionate number of elderly patients suffer from oropharyngeal dysphagia with a multifactorial etiology. Historically, treatment options have been limited and included mostly supportive care with a focus on dietary modification, food avoidance, and swallow rehabilitation. Nascent technologies such as the functional luminal imaging probe (FLIP) and advances in esophageal manometry are improving our understanding of the pathophysiology of oropharyngeal dysphagia. Recent developments in the treatment of specific causes of oropharyngeal dysphagia, including endoscopic balloon dilations for upper esophageal sphincter (UES) dysfunction, show promise and are expected to enhance with further research. Esophageal dysphagia is also common in the elderly and more commonly due to an identifiable cause. The full breadth of treatment options is frequently unavailable to elderly patients due to comorbidities and overall functional status. However, the increasing availability of less invasive solutions to specific esophageal pathologies has augmented the number of treatment options available to this population, where an individualized approach to patient care is paramount. This review focuses on the evaluation and management of dysphagia in the elderly and delineates how standard and novel therapeutics are contributing to more nuanced and personalized management.

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