Animals that have simple eyes are thought to only detect crude visual detail such as light level. However, predatory insect larvae using a small number of visual inputs seem to distinguish complex image targets. Here we show that Drosophila melanogaster larvae, which have 12 photoreceptor cells per hemisphere, are attracted to distinct motions of other, tethered larvae and that this recognition requires the visual system but not the olfactory system. In addition, attraction to tethered larvae still occurs across a clear plastic barrier, does not occur significantly in the dark and attraction occurs to a computer screen movie of larval motion. By altering the artificial attractant movie, we conclude that visual recognition involves both spatial and temporal components. Our results demonstrate that a simple but experimentally tractable visual system can distinguish complex images and that processing in the relatively large central brain may compensate for the simple input.
Background: The incidence of esophageal adenocarcinoma (EAC) has been increasing over the last 40 years. While Barrett's esophagus is a known risk factor for the development of EAC, the role of the microflora in the development of EAC is still largely unknown and is being investigated further by multiple centers. Our goal was to identify trends in microflora composition along various aspects of the upper gastrointestinal tract in patients with Barrett's esophagus. Methods: After obtaining institutional review board approval, 12 patients agreed to participate in the study.While endoscopy was performed for surveillance Barrett's monitoring, additional biopsies of esophageal mucosa were taken from the (I) proximal esophagus, (II) mid-esophagus, (III) distal esophagus, and (IV) Barrett's esophagus. Additional swabs were also taken from the uvula and the endoscope used during the procedure. The swabs from the uvula and endoscope were obtained prior to the endoscope entering the stomach, to prevent exposing the endoscope to the acidic environment of the stomach. The most common bacterial elements were identified by amplifying sample DNA using a panel of 5 "universal" fusion primer pairs. The 400-500 base pair fragments created an overlap which covered 95% of the bacterial 16s gene. Results: Throughout the esophagus, 34 bacterial genera were found which had a relative abundance of >1.0. Streptococcal genera were prevalent in all aspects of the esophagus, ranging from 16% to 70% of the bacterial community. Haemophilus genera were uniquely abundant in the Barrett's esophageal tissue but relatively absent elsewhere in the upper gastrointestinal tract. Overall, the percentage of Gram-positive organisms was much higher in the proximal than distal esophagus. The microflora pattern obtained from the uvula and endoscopic swabs did not correlate with any of the tissue biopsies along any aspect of the esophagus. Conclusions: In patients with Barrett's esophagus, Streptococcal genera are widespread throughout the esophagus. Gram-positive genera tend to decrease as a percentage of overall flora distally. Obtaining a simple swab of the oropharynx or endoscope itself appears to be a poor substitute for tissue biopsy of esophageal mucosa when evaluating microflora patterns.
The incidence of esophageal diseases such as esophageal adenocarcinoma (EAC) and gastroesophageal reflux disease (GERD) have been increasing over the last 40 years. The esophageal microbiome appears to have a role in the development of some disease processes, and could also serve as markers of early diseases of the esophagus. A literature review was performed examining the role of the microbiome in the development of esophageal disease. In addition, the results of several studies and experiments were included in the review. Both EAC and GERD have increased in incidence over the last 40 years. Barrett's esophagus (BE) is a risk factor for EAC. Patients with BE appear to have a microbiome expression pattern distinct from patients without BE. The distinct pattern may be related to factors within the distal esophagus such as a more acidic environment, intraluminal stasis and other elements. It remains unclear whether the change in microflora leads to esophageal disease, or whether the disease process within the esophagus allows these particular organisms to experience overgrowth compared to other microflora.Patient factors such as body mass index (BMI), diet and geographic location also appear to affect the esophageal microbiome. There is an association with the esophageal microbiome and several esophageal diseases. Future studies should examine these correlations more closely. The distinct patterns may be able to serve as a marker of early disease, and possibly lead to a mechanism for the development of esophageal disease.
The role of the microflora in the development of esophageal disease is still largely unknown and is being investigated in more detail. Our goal was to determine how the microbiota levels of endoscope and uvular swabs compared to the levels of tissue biopsies along various points of the esophagus. 17 patients with Barrett’s esophagus agreed to participate in the study. Biopsies of esophageal mucosa were taken from the (1) proximal esophagus, (2) mid-esophagus, (3) distal esophagus, and (4) Barrett’s esophagus. Swabs were also taken from the uvula and the endoscope. Throughout the esophagus, 17 bacterial genera were detected from the samples. The microflora pattern obtained from the uvula and endoscopic swabs did not correlate well with mucosal biopsies along any aspect of the esophagus. There were statistically significant differences in the levels and proportions of bacteria found when comparing the uvula swab to the esophageal biopsies and when comparing the endoscope swab to the esophageal biopsies. Obtaining a simple swab of the uvula or endoscope itself appears to be a poor substitute for tissue biopsy of esophageal mucosa when evaluating microflora patterns. When performing microflora studies of the esophagus, mucosal biopsies should be used for analysis.
Single‐pass transmembrane proteins (TM1) are a diverse group of proteins characterised by a single transmembrane domain. In total, the authors found approximately 1300 TM1 proteins in the human genome, most of which have characterised functions. The extracellular domains of these proteins range up to 22 000 amino acids with an average size being six times larger than intracellular domains. This suggests that these proteins have evolved the capacity to bind a wide array of ligands and substrates. Consequently, these proteins are involved in many processes, such as adhesion, migration, growth and cell death, among others. Although many act as receptors for first messengers (extracellular signalling molecules), they can also serve as ligands, adaptors, proteases and coreceptors. Herein, the authors provide a broad overview of these different roles along with examples of their involvement in pathological and physiological situations. Key Concepts: Single‐pass transmembrane proteins participate in signalling in a variety of ways, either as ligands, receptors, enzymes coreceptors and/or adaptors. TM1 proteins appear to have undergone evolutionary expansion as a function of body plan complexity. The extracellular domains of TM1 proteins cluster well based on family, whereas the intracellular domains do not. TM1 proteins are adapted to bind very large substrates/ligands compared with other receptor families (ion channels and GPCRs). TM1 have roles in every organ system and are particularly important in the immune and nervous systems.
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