Fetal Duodenum Research Articles

Ultrasound examination of the normal fetal duodenum.

To use the fetal pylorus as a reference point to conveniently display the normal fetal duodenum by ultrasound. This study was designed in cross-section. A total of 450 healthy singleton pregnant women at 19-39 weeks of gestation who underwent prenatal screening at our hospital from January 2019 to February 2020 were selected. They were divided into three groups according to gestational weeks: the 19-23 gestational weeks group, 29-32 gestational weeks group, and 34-39 gestational weeks group. The duodenal bulb was identified. Its movement and course were continuously and dynamically observed. The descending part of the duodenum was identified, and the duodenal course was traced. The fluid-filled in the fetal duodenum was discontinuous. The overall detection rates of the duodenum in the 19-23 gestational weeks group, 29-32 gestational weeks group, and the 34-39 gestational weeks group were 82.2%, 26.2%, and 13.8%, respectively. The detection rates of the bulbar, descending, horizontal, and ascending parts of the duodenum were 94.4%, 58.2%, 58.0%, and 52.0%, respectively. The anatomical structures of the duodenum as a whole and the pancreas were most easily recognized in the 19-23 gestational weeks group; while in the 34-39 gestational weeks group, the bulbar part had a maximum detection rate of 98.8%, and it had the longest filling time and the shortest examination time. The pylorus is an ideal starting point for tracing the fetal duodenum. The overall detection rate of the fetal duodenum decreases with gestational age. The duodenal bulb is the most easily detected site.

Heat Stress Modulates a Placental Immune Response Associated With Alterations in the Development of the Fetal Intestine and Its Innate Immune System in Late Pregnant Mouse.

The placenta is critical for the regulation of fetal innate immune function. Maternal heat stress (HS) impairs the immune function and the intestinal barrier in the offspring. However, the effects of maternal HS on the placental immune response and the development of the fetal intestine and its innate immune system remain unclear. Fetal mice were divided into the utero control (IUTN) and heat stress (IUHS) groups according to the maternal ambient temperature. Transcriptome analysis revealed that the expressions of placental immune response–related genes such as macrophage antigen CD68 and Fc gamma receptors 1 and 3 (fcgγ1 and fcgγ3) were increased, but the mRNA expression and protein levels of colony-stimulating factor-1 (Csf1) were decreased in the HS group compared with the TN group (p < 0.05). Furthermore, there was no significant difference in the intestinal length normalized to pup weight between the IUTN and IUHS groups. The expression of genes (such as alpi and ttr) involved in fetal duodenum and jejunum development was downregulated by maternal HS, whereas the expression of genes enriched in the cell cycle was increased. The mRNA expression and protein levels of cell division cycle 6 (Cdc6) in the fetal duodenum and jejunum were much higher in the IUHS group than in the IUTN group (p < 0.05). Maternal HS also down-regulated the expression of genes enriched in the innate immune system in the fetal duodenum and jejunum. The mRNA expression and protein levels of interleukin 1 alpha (IL1a) were reduced in the IUHS group compared with the IUTN group (p < 0.05). Taken together, these data demonstrated that maternal HS modulated the expression of genes in the placenta related to the immune response and inhibited the development of the fetal intestine and its innate immune system.

Heat stress affects fetal brain and intestinal function associated with the alterations of placental barrier in late pregnant mouse

High ambient temperature-induced heat stress (HS) during pregnancy may affect the placental function and fetal development. Late gestation is a critical period of the developing fetal brain and intestine. The study aimed to investigate the effects of HS during late pregnancy on the function of placenta, fetal brain and intestine in a mouse model. We found that the number of stillborn fetal mice were increased due to maternal HS. Transcriptome analysis revealed that the expression of genes enriched in nutrients transport and metabolism of HS group were up-regulated in the placenta, but down-regulated in the fetal duodenum and jejunum. Interestingly, the concentration of triglyceride (TG) in the HS group was raised in the placenta, but reduced both in the fetal duodenum and jejunum compared with the thermal-neutral (TN) group. Additionally, maternal HS also reduced total cholesterol (TC) contents in the fetal duodenum. The mRNA expression and protein levels of placental fatty acid binding protein 2 and 4 (fabp2 and fabp4) were not affected by maternal HS, but the mRNA expression and protein levels of cluster of differentiation 36 (CD36) and diacylglycerol acyltransferase-2 (Dgat2) were decreased in the fetal intestine. Furthermore, maternal HS reduced the mRNA expression and protein levels of the placental 11beta-hydroxysteroid dehydrogenase type 2 (Hsd11b2) and 5-hydroxytryptamine receptor 1D (Htr1d). The concentrations of corticosterone and the expression of heat shock protein 90 beta family member 1 (hsp90b1), hypoxia up-regulated 1 (hyou1) and corticotropin releasing hormone receptor 1 (crhr1) enriched in response to glucocorticoids in the fetal brain were increased by maternal HS. Taken together, our findings demonstrated that maternal HS disrupted the placental glucocorticoid barrier and serotonin system associated with the raised corticosterone levels in the fetal brain, which might contribute to the decreased capacity of nutrients transport and metabolism in the fetal intestine.

Duodenal web presenting outside the neonatal period concurrently with malrotation and mid-gut volvulus

Abstract Fetal development of the intestinal tract involves multiple embryological events at the culmination of which the duodenojejunal junction is fixed in the left upper quadrant and cecum in the right lower quadrant. Developmental anomalies affecting the normal rotation of the fetal intestines occur as frequently as 1% of the population. Patients with malrotation are at risk for midgut volvulus, a surgical emergency with potential catastrophic outcomes with an incidence of 1:6000. Congenital duodenal atresia and stenosis is a frequent cause of intestinal obstruction in neonates and the incidence is estimated to be between 1:4000–15000 livebirths. Developmental failure of the recanalization of the fetal duodenum leads to an intrinsic web or atresia. Classically, malrotation with midgut volvulus is often diagnosed in a previously healthy term neonate with bilious emesis. While duodenal webs can have a similar presentation, the concurrence of both pathological entities leading to bowel obstruction is rarely reported. In this report we present a case of a 2 year old previously asymptomatic male child presenting with bilious emesis and found to have malrotation with volvulus and a concurrent duodenal web.

Enterocytic CYP3A4 in a paediatric population: developmental changes and the effect of coeliac disease and cystic fibrosis.

To investigate the effects of age and disease states on the expression and activity of intestinal CYP3A4 in a paediatric population. Duodenal biopsies and surgical sections were collected from 104 paediatric patients (age range 2 weeks to 17 years) and from 11 foetuses. An S9 fraction was prepared in each case. CYP3A4 expression was assessed by Western blotting and by immunohistochemistry; activity was measured by the rate of formation of 6beta-hydroxytestosterone from testosterone. Villin expression was used as a marker of enterocyte harvest to normalize CYP3A4 expression and activity data. In the 74 histologically normal paediatric biopsies there were statistically significant increases in CYP3A4 expression (r2 = 0.19, P = 0.001) and activity (r2 = 0.17, P = 0.02) with age. CYP3A4 was practically absent in fetal duodenum and was expressed at relatively low levels in neonates (P < 0.05 between neonates and children > 5 years). Active coeliac disease resulted in significant (P < 0.001) decreases in CYP3A4 expression and activity. Duodenal CYP3A4 is present at significantly lower levels in neonates and in patients with active coeliac disease. This may have clinical significance with respect to the oral bioavailability of CYP3A4 substrates.

Developmental mucin gene expression in the gastroduodenal tract and accessory digestive glands. II. Duodenum and liver, gallbladder, and pancreas.

Studies were undertaken to provide information regarding cell-specific expression of mucin genes and their relation to developmental and neoplastic patterns of epithelial cytodifferentiation. In situ hybridization was used to study mRNA expression of mucin genes in duodenum and accessory digestive glands (liver, gallbladder, pancreas) of 13 human embryos and fetuses (6. 5-27 weeks' gestation), comparing these with normal and neoplastic adult tissues. These investigations demonstrated that the pattern of mucin gene expression in fetal duodenum reiterated the patterns we observed during gastric and intestinal ontogenesis, with MUC2 and MUC3 expression in the surface epithelium and MUC6 expression associated with the development of Brünner's glands. In embryonic liver, MUC3 was already expressed at 6.5 weeks of gestation in hepatoblasts. As in adults, MUC1, MUC2, MUC3, MUC5AC, MUC5B, and MUC6 were expressed in fetal gallbladder, whereas MUC4 was not. In contrast, MUC4 was strongly expressed in gallbladder adenocarcinomas. MUC5B and MUC6 were expressed in fetal pancreas, from 12 weeks and 26 weeks of gestation, respectively. Surprisingly, MUC3 which is strongly expressed in adult pancreas, was not detected in developmental pancreas. Taken together, these data show complex spatio-temporal regulation of the mucin genes and suggest a possible regulatory role for mucin gene products in gastroduodenal epithelial cell differentiation.

Distention of the fetal duodenum: abnormal finding?

We investigated whether a fluid-filled duodenum is observed in normal fetuses. In part 1 of the study a view in the region of the duodenum was obtained during routine obstetric ultrasonography from 123 low-risk patients. All examinations demonstrated a collapsed duodenum. No gastrointestinal abnormalities were found in these infants. In part 2 of the study, 1163 fetuses (both high-risk and low-risk) were evaluated with real-time scanning, and duodenal fluid without a "double bubble" was seen in one fetus who had a duodenal web. We conclude that a nondistended fetal duodenum is the norm. If fetal duodenal dilation is visualized, this may allow for earlier detection of duodenal obstructions.

EFFECT OF MURINE AND HUMAN YOLK SACS ON THE DEVELOPMENT OF THE FETAL MOUSE DUODENUM IN ORGAN CULTURE

When 15-day fetal mouse duodenum is cultured for 48 hours in Trowell T8 medium, villi do not form and crypts or crypt-like structures are scanty. In vivo villi differentiate at 16 days of gestation and crypts appear three days later. If the same culture medium is supplemented with an organic extract of 19-day rat amniotic fluid well differentiated crypts are present in the explants after 48 hours of culture. This effect was attributed to the presence of a crypt differentiation factor (CDF) in the amniotic fluid. When fetal duodenum is cultured with immersed fragments (25 mg) of 19-day fetal rat visceral yolk sac (VYS) or with T8 medium conditioned by a 24 hour incubation with VYS fragments, a high CDF activity is observed. VYS incubated for 6 hours in T8 medium is completely degranulated and the medium exhibits a strong CDF activity. Subcellular fractionation of VYS by differential centrifugation in sucrose reveal that the most active fraction showing CDF activity is the richest in large granules. Human yolk sac was taken from a 38-39 day embryo following a preventive abortion (tubal implantation). When 15-day fetal mouse duodenum is cultured in presence of half of the human yolk sac (HYS), villi and crypts differentiate in the duodenal segments. It appears that HYS also has a CDF activity. (Supported by grant No. MT-6069 from the Medical Research Council of Canada)

Role of thyroxine and insulin on the development of the fetal mouse duodenum in organ culture.

The role of thyroxine and insulin in the regulation of proliferation and differentiation of the immature duodenal epithelium of the fetal mouse was investigated using an organ culture method with a serum-free medium. Thyroxine (10 nM) stimulates specifically the activity of maltase. Insulin (125 mU/mL) remains without effect on the maturation of all hydrolytic functions studied. Each hormone significantly increases the percentages of brush border enzyme activities liberated in the medium and reduces the amount of glucose released in the medium. In the presence of dexamethasone (76 nM) the effect of thyroxine on maltase activity is still observed. Finally, thyroxine and insulin do not modify the labelling index in the duodenal crypts of the explants in the presence or absence of dexamethasone. These findings indicate that thyroxine and insulin can act directly on the development of the fetal mouse duodenum at the end of gestation. Nevertheless, their implication in prenatal development of the gut functions appears to be of minor importance.

Immunohistochemical localization of pancreatic secretory trypsin inhibitor in fetal and adult pancreatic and extrapancreatic tissues.

Pancreatic secretory trypsin inhibitor (PSTI) has been thought to be only a secretory trypsin inhibitor of human pancreas, but the serum content of immunoreactive PSTI is elevated without pancreatic disease. Using the peroxidase-antiperoxidase method, immunoreactive cells for PSTI were found in human pancreas, stomach, duodenum, appendix, colon and urinary tract of both fetus and adult, adult gall bladder, and fetal lung. PSTI-immunoreactive cells were identified in fetal pancreas at the tenth gestational week, and in extrapancreatic tissues at the sixteenth (gastrointestinal and urinary tract) and twentieth weeks (lung). PSTI-immunoreactive cells of fetal lung were present in neuroepithelial bodies. Strongly positive cells in fetal duodenum were argyrophilic and resembled endocrine cells. Immunohistochemical study was also performed on tissues associated with inflammatory diseases of gastrointestinal tract. The distribution pattern of immunoreactive cells in the stomach varied in accordance with chronic gastritis. Immunoreactive cells were also found in endocrine micro-nests and in a carcinoid tumor associated with fundic gastritis. These results suggest that PSTI may play some physiological role other than secretory trypsin inhibition of the pancreas.

Intestinal metaplasia and carcinomas of the human stomach: an immunohistological study.

Rabbit immunization with duodenal or colonic high molecular weight components allowed us to distinguish three new M3 antigens associated with intestinal goblet cells; these were denoted as M3SI, M3D, and M3C. Using immunoperoxidase staining, the anti-M3SI serum labeled all goblet cells in the small intestine, and a certain number of them in the colon, mainly in its proximal part. The anti-M3D serum reacted primarily with the goblet cells of the duodenal villosities, and the anti-M3C serum with all goblet cells of the large, but not the small, intestine. Moreover, the M3C antigen was recovered in some goblet cells of the fetal duodenum, in association with the two other markers. Only the M3D and the M3SI antigens were observed in the normal duodenum and intestinal metaplasia (IM) of benign gastric mucosa. In contrast, IM adjacent to gastric carcinomas, whatever their histological type, contained the M3C antigen in addition to M3D and M3SI antigens, and thus showed an antigenic pattern similar to fetal duodenum. Some gastric carcinomas, especially those with intestinal-like differentiation, produced the colonic M3C antigen as the neighboring IM. Thus, these two tissues displayed common differentiation features, which could be related to fetal duodenum rather than to adult colon.

Fine structure of the basal-granulated cells in human fetal duodenum.

Fine structure of the duodenal mucosa in ten human fetuses 4 to 7 months old was studied by light and electron microscopy using Epon-embedded specimens. Cells containing membrane-bound granules were found both in the connective tissue and in the epithelia and identified to be basal-granulated cells, since they essentially corresponded in their cytoplasmic fine structures to the named cells in the adult. However, their relation to nerves and epithelial elements revealed some primitive features. In the 4 month fetus, the basal-granulated cells were seen in the lamina propria forming clusters which were often in contact with the basal part of the epithelium. In the 5 month fetus, occurrence of clustered basal-granulated cells in the connective tissue was among other epithelial cells, gaining an apical process which reached the lumen. The basal-granulated cells in the lamina propria were frequently surrounded by a Schwann-like cell. Profiles of unmyelinated nerve fibers were ample in the space between the Schwann-like cell and the basal-granulated cell. An phi-shaped invagination of the basal plasma membrane encompassing granular material was often found in the D type basal-granulated cells in the 7 month fetus. This suggests that the secretion of at least some of the basal-granulated cells starts in the prenatal period by emiocytosis.