Foregut Wall Research Articles

Aortic injuries following stents in bariatric surgery: our experience.

Due to the large number of laparoscopic sleeve gastrectomy (LSG) performed over the last decade, the management of the leak following LSG has been increasingly reported. The role of covered Self Expandable Metal Stents (cSEMS) for the treatment of the leak is still controversial because of the poor tolerance and high risk of complications. The aim of the present study was to analyze the foregut wall perforation and aorta injuries, a very rare but potentially fatal complication, related to the treatment of the leak following LSG using cSEMS. Private hospital, France. An audit was conducted in 2 French tertiary bariatric endoscopic centers focusing on aortic injuries after cSEMS use for leak. We examined and classified the initial procedure, leak characteristics, primary endoscopic treatment, and outcome of endoscopic complication for each eligible case. A total of 5 patients were identified with foregut wall perforation and aorta injuries. All stents were deployed for staple line leak following LSG. The recorded mortality in case of esophageal-aortic injuries related to cSEMS use was 80%. cSEMS are potentially effective tools for the management of foregut leaks in bariatric surgery. The biggest challenges with this approach are stent migration and poor quality of life. Caution is required due to the risk of fatal complications such as foregut wall perforation and aorticinjury.

New lessons from ancient life: marine invertebrates as a source of new drugs

Introduction: Whether as defence against predators and parasites or as a weapon for hunting, time and natural selection provided animals with a myriad of toxins, antibiotics and other specialised chemical warfare [1]. Time and evolution thus generated a broad range of biomolecules able to interfere with almost every biological pathway, rendering redundant the costly, laborious and high-risk process of designing synthetic compounds. Not surprisingly, given the oceans’ immense biodiversity, bioprospecting the seas for new bio-reactive drugs became a corner stone of the EU ‘Biotechnology for Blue Growth’ strategy. Motivated by the first drugs derived from marine animals, such as Prialt [2], and Portugal’s vast coastline, we have been screening marine invertebrates for novel compounds of biotechnological interest, while aiming at developing the tools that enable efficient marine bioprospecting at all levels of biological organisation: from marine ecology to molecular biology. Materials and methods: Phyllodocid annelids, the muricid gastropod Nucella and their regular prey (e.g. mussels) were collected from rocky beaches at W and SW Portugal. A battery of techniques, including behaviour-directed assays, cytology, histology, plus biochemichal and molecular tools (like oligonucleotide sequencing and PCR to screen for bacteriome-specific rRNAs) have been applied to identify novel substances, locate their production and assess their properties. Results: We were able to localise special cells and glands of annelids and gastropods (Figure 1) where many novel substances are produced, stored and secreted. This includes potential toxins [3] and their accompanying enzymes. Also, we isolated novel porphyrin-like pigments (which may be important biocidals and antioxidants) and even proteinaceous fluorochromes from our phyllodocid case-study, Eulalia. Among other results, the findings suggest that the microbiome associated to this species may include novel species of symbiotic bacteria. Figure 1. Histological section of secretory epithelia of Nucella showing serous cells in the foregut wall (arrow) and salivary glands (sg), where toxins are produced. Discussion and conclusions: Toxins have unique biotechnological value because they interfere with specific biological pathways. Findings support the choice of Eulalia and Nucella from the Portuguese coast as prime targets for bioprospecting. Still, toxins are just a few among many valuable bioproducts so far disclosed. Altogether, the results show that we are just scraping the tip of the iceberg of novel substances with pharmacological potential from marine invertebrates.

Stent-over-sponge (SOS): a novel technique complementing endosponge therapy for foregut leaks and perforations

Endoluminal vacuum therapy (EVT) has evolved as a promising option for endoscopic treatment of foregut wall injuries in addition to the classic closure techniques using clips or stents. To improve vacuum force and maintain esophageal passage, we combined endosponge treatment with a partially covered self-expandable metal stent (stent-over-sponge; SOS). Twelve patients with infected upper gastrointestinal wall defects were treated with the SOS technique. Indications for SOS were anastomotic leakage after surgery (n = 11) and chronic foregut fistula (n = 1). SOS treatment was used as a first-line treatment in seven patients with a success rate of 71.4 % (5/7) and as a second-line treatment after failed previous EVT treatment in five patients (success rate 80 %; 4/5). Overall, SOS treatment was successful in 75 % of patients (9/12). No severe adverse events occurred. CONCLUSION : SOS is an effective method to treat severely infected foregut wall defects in patients where EVT has failed, and also as a first-line treatment. Comparative prospective studies are needed to confirm our preliminary results.

Zoology: A New Mouth for Amphioxus

Deuterostomes - a key subdivision of animals - are characterized by the mouth developing anteriorly as a rupture between the outer epithelium and the foregut wall. A new study of amphioxus challenges this view and proposes separate evolutionary origins of deuterostome oral openings.

Effects of antisense misexpression of CFC on downstream flectin protein expression during heart looping

Dextral looping of the heart is regulated on multiple levels. In humans, mutations of the genes CFC and Pitx2/RIEG result in laterality-associated cardiac anomalies. In animal models, a common read-out after the misexpression of laterality genes is heart looping direction. Missing in these studies is how laterality genes impact on downstream morphogenetic processes to coordinate heart looping. Previously, we showed that Pitx2 indirectly regulates flectin protein by regulating the timing of flectin expression in one heart field versus the other (Linask et al. [2002] Dev. Biol. 246:407-417). To address this question further we used a reported loss-of-function approach to interfere with chick CFC expression (Schlange et al. [2001] Dev. Biol. 234:376-389) and assaying for flectin expression during looping. Antisense CFC treatment results in abnormal heart looping or no looping. Our results show that regardless of the sidedness of downstream Pitx2 expression, it is the sidedness of predominant flectin protein expression in the extracellular matrix of the dorsal mesocardial folds and splanchnic mesoderm apposed to the foregut wall that is associated directly with looping direction. Thus, Pitx2 can be experimentally uncoupled from heart looping. The flectin asymmetry continues to be maintained in the secondary heart field during looping.

ULTRASTRUCTURAL FEATURES OF THE FUNNEL OF GAMMARUS OCEANICUS (AMPHIPODA)

Abstract The funnel of Gammarus oceanicus extends as a fold of the foregut wall into the midgut lumen. It comprises an anterior segment, to which both foregut epithelium and cuticle contribute, and a posterior segment that lacks the epithelium. The latter segment consists of two layers of foregut cuticle that are in close contact and extend distally beyond the point where the foregut epithelium turns back on itself; contact between the two cuticular layers develops as the epithelium retracts from between them, in postmolt. Light microscopy does not consistently distinguish between the funnel's posterior segment and the peritrophic membrane found within mid- and hindguts; however, their ultrastructural organizations are distinctly different, and an origin of peritrophic membrane from the funnel of some amphipods, as suggested in the literature, is not the case for Gammarus oceanicus. Scattered within the posterior segment cuticle are clusters of short, highly curved, electron-lucent rods. Such features hav...

Heterotopic Gastric Tissue in the Scrotum

A 2-year-old boy who underwent right inguinal herniotomy as a neonate presented with a right hydrocele. Exploration revealed a large hydrocele sac containing a creamy fluid with 2 interconnecting compartments and no patent processus vaginalis. The upper pouch was excised and the lower pouch was opened, according to Jaboulay’s operation. Histology of the sac revealed gastric heterotopia (see figure). Postoperatively a 99mtechnetium pertechnetate scan failed to demonstrate any residual gastric tissue. The patient presented 2 years later with recurrent hydrocele, which was aspirated (pH 7.34). Ten months later he is asymptomatic. DISCUSSION Heterotopia refers to the presence of tissues at sites where they are not normally found. Heterotopic gastric mucosa has been described throughout the length of the gastrointestinal tract, including the hepatobiliary system, and in the skin of the abdominal wall.’ To our knowledge we report the first case of heterotopic gastric mucosa in the scrotum. The embryonic foregut initially comprises a continuous endodermal tube encased in a thick stratum of mesoderm, which provides most of the mural and connective tissue framework of the foregut wall. In the region of the future stomach this mesodermal thickness forms a part of the primitive peritoneal cavity by clefting, cavitation and subsequent coalescence. During this process a portion of gastric mucosa, while remaining in the midline, may have been displaced into the primitive peritoneal cavity, and then may have migrated down with the testis into the scrotum. In contrast, ectopic splenic tissue has been noted only in the leR scrota1 compartment.z Our second hypothesis is that ectopic tissue developed from existing pluripotential cells in that region, which is supported by the fact that aberrant adrenal tissue has been described in the wall of the hernial sac and in the In conclusion, our case illustrates that heterotopia is not only of

Heterotopic Gastric Tissue in the Scrotum

A 2-year-old boy who underwent right inguinal herniotomy as a neonate presented with a right hydrocele. Exploration revealed a large hydrocele sac containing a creamy fluid with 2 interconnecting compartments and no patent processus vaginalis. The upper pouch was excised and the lower pouch was opened, according to Jaboulay’s operation. Histology of the sac revealed gastric heterotopia (see figure). Postoperatively a 99mtechnetium pertechnetate scan failed to demonstrate any residual gastric tissue. The patient presented 2 years later with recurrent hydrocele, which was aspirated (pH 7.34). Ten months later he is asymptomatic. DISCUSSION Heterotopia refers to the presence of tissues at sites where they are not normally found. Heterotopic gastric mucosa has been described throughout the length of the gastrointestinal tract, including the hepatobiliary system, and in the skin of the abdominal wall.’ To our knowledge we report the first case of heterotopic gastric mucosa in the scrotum. The embryonic foregut initially comprises a continuous endodermal tube encased in a thick stratum of mesoderm, which provides most of the mural and connective tissue framework of the foregut wall. In the region of the future stomach this mesodermal thickness forms a part of the primitive peritoneal cavity by clefting, cavitation and subsequent coalescence. During this process a portion of gastric mucosa, while remaining in the midline, may have been displaced into the primitive peritoneal cavity, and then may have migrated down with the testis into the scrotum. In contrast, ectopic splenic tissue has been noted only in the leR scrota1 compartment.z Our second hypothesis is that ectopic tissue developed from existing pluripotential cells in that region, which is supported by the fact that aberrant adrenal tissue has been described in the wall of the hernial sac and in the In conclusion, our case illustrates that heterotopia is not only of

Migration and distribution of circumpharyngeal crest cells in the chick embryo. Formation of the circumpharyngeal ridge and E/C8+ crest cells in the vertebrate head region.

The cardiac neural crest is located in a transitional area on the neuraxis between trunk and cephalic regions and gives rise to both the dorsolateral and ventrolateral crest cell populations. Around stage 18 of chick development, a mass of E/C8+ cells surrounds the postotic pharyngeal arches and forms a crescent-shaped arch, termed the circumpharyngeal ridge. Using immunohistochemistry and quail-chick chimeras, it was determined that the E/C8+ cell mass located in the circumpharyngeal ridge derives from the dorsolateral component of the cardiac neural crest. The ventrolateral cell population of the cardiac crest is located more medially and shows long-persistent HNK-1 immunoreactivity dorsolateral to the foregut. The crest cells that populate the gut arise from the caudal portion of the circumpharyngeal crest and are always located caudal to the caudal-most pharyngeal ectomesenchyme. Circumpharyngeal crest cells continuously populate the pharyngeal arch ectomesenchyme and enteric nervous system on the lateral side of the foregut wall, as well as the hypoglossal pathway which develops within the ventral portion of the circumpharyngeal ridge. E/C8 and HNK-1 immunoreactivity are associated with the cells migrating via the dorsolateral (circumpharyngeal) and ventrolateral pathways, respectively, with one exception: there is a population of putative crest cells along the proximal course of the vagal intestinal branch that shows both immunoreactivities around stage 20. DiI labeling of the cells in the circumpharyngeal ridge suggests that the cells are contributed from the circumpharyngeal ridge to this population. Thus, the distribution of the circumpharyngeal crest cells and their derivatives coincides with the peripheral branch distribution of the cranial nerves IX, X, and XII, whose development is selectively affected in the absence of the cardiac neural crest, the source of the circumpharyngeal crest.

The embryology of foregut malformations

Developmental disorders in the period of the differentiation of the primitive foregut leads to atresia of the esophagus with tracheoesophageal fistula. Most authors think that this differentiation is caused by lateral foregut folds, which fuse in midline, thus forming the tracheoesophageal septum. In order to gain information about this period of development, we studied the foregut region of chick embryos by scanning electron microscopy (SEM) and light microscopy. In our study no signs of lateral folds or fusing foregut wall components, which were forming a tracheoesophageal septum, were found. Our study suggests that the development of the esophagus and trachea is the result of a simple reduction of the size of the primitive foregut. The consequence for the understanding of the embryology of the foregut malformations is discussed.

A study of Enterogyrus sp. (Monogenea) parasitizing the foregut of captive Pomacanthus paru (Pomacanthidae) in Georgia

A species of Enterogyrus Paperna, 1963 (Monogenea: Ancyrocephalidae) parasitizing the foregut of a captive Pomacanthus paru (Pomacanthidae) in Georgia was studied in situ both histologically and with scanning electron microscopy. The worms are found at the junction of the esophagus and stomach and arrange themselves with their main body axis directed perpendicular to longitudinal folds in the foregut wall. They cling to host tissue principally by blades of the pair of large dorsal hamuli and apparently rely little on the action of the pair of small ventral hamuli and the 14 marginal hooks. It is argued that this adhesive attitude allows unrestricted movement when peristaltic waves move along the gut and the worm thereby maintains a stable footing. The body tegument is unusually thick (2 to 5 μm) for the worm's size. Dorsally it is smooth and devoid of microvilli. Ventrally it is thrown into transverse folds having small microvilli and unique round to oval papillae that measure up to 7 μm in diameter. Evidently the modified tegument is an adaptation to life in the foregut, possibly serving to protect worms from digestive enzymes. The study represents the first report of Enterogyrus from a marine host.

HISTOLOGY OF SELECT ORGANS OF THE CRAWFISH Procambarus clarkii MAINTAINED AT VARIOUS TEMPERATURES AND LEVELS OF CALCIUM AND AMMONIA1,2

ABSTRACTHistologic changes were observed in shell, hepatopancreas, gut and gill tissues of crawfish Procambarus clarkii maintained in aquaria containing various levels of dissolved calcium (16, 86, 192 and 300 ppm), temperature (15, 21 and 27°C) and ammonia (<0.5 and 1.00 ppm, at each of the three temperatures). The principal changes observed among all treatment groups included: melanized necrosis of the shell, of the cuticular lining of the foregut, hindgut and gill, and in the parenchymal tissues of the hepatopancreas, gill and hindgut. An inflamnatory response characterized by infiltration of hemocytes, fibrocytes and collagen‐like material accompanied necrosis in the hepatopancreas. In addition, eosino‐philic granular hemocytes were seen in the hepatopancreas, the foregut wall and in the gill. A globular, deeply basophilic material was observed in the subcutis of the hindgut.

The lipid composition of the foregut wall of Carcinus maenas and its relationship to observed permeability

Abstract 1. 1. The detailed biochemical composition of the epidermis and cuticle from the foregut in Carcinus maenus has been examined. 2. 2. The cuticle was composed mainly of protein and chitin with a relatively small lipid component whilst the epidermis was rich in both protein and lipid. 3. 3. The sterol fractions of both tissues were composed almost entirely of cholesterol but the component phospholipids were quite distinct. 4. 4. The phospholipids of the epidermis were composed mainly of long chain, highly unsaturated fatty acids, whilst those of the cuticle were dominated by short-chain saturated fatty acids. 5. 5. These compositional differences are discussed in relation to the likely permeabilities of the tissues.