Topic
Microcolon
About: Microcolon is a research topic. Over the lifetime, 245 publications have been published within this topic receiving 3695 citations.
Papers published on a yearly basis
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Papers
TL;DR: MRI provided complete visualisation of the fetal GI tract, showed specific signal intensities, identified the level of an obstruction, detected a microcolon, and demonstrated communication between urinary and GI tracts.
Abstract: Objective: To determine the MRI patterns of the gastrointestinal (GI) tract in normal fetuses and some GI tract abnormalities. Materials and methods: A retrospective (1996–1998) and prospective (1999–2000) study of 48 fetal abdominal MRI scans was performed between 23 and 38 weeks of gestation. T1-weighted (T1-W) fast gradient-echo (Flash 2D) and T2-weighted (T2-W) HASTE sequences were obtained on a 1.5-T unit, in frontal and sagittal planes, after maternal premedication. Fresh meconium was also studied. Results: Normal patterns (40 cases): the rectum was seen in all cases and exhibited meconium-like high signal on T1-W images and low signal on T2-W images. It was close to the bladder whatever the fetal gender with its cul-de-sac being at least 10 mm below the bladder neck. The large bowel had a same signal; the distal colon was demonstrated more frequently than the proximal colon. The small bowel was transiently hyperintense on TI-W images early in gestation and then hyperintense on T2-W images. Normal measurements were obtained. GI tract abnormalities (eight cases): cysts close to normal bowel (n=2), atresias (n=5; microcolon, dilated small bowel with abnormal signal, one with a meconium cyst) and a cloacal malformation with midgut malrotation (n=1; abnormal liquid signal in the rectum separated from the bladder wall and colon located on the left side). Conclusions: MRI provided complete visualisation of the fetal GI tract, showed specific signal intensities, identified the level of an obstruction, detected a microcolon, and demonstrated communication between urinary and GI tracts. It shows great potential.
171 citations
TL;DR: The pathogenesis of MMIHS is reviewed as well as the clinical, radiological, surgical and histological findings in all reported cases of this syndrome.
119 citations
TL;DR: LMOD1 is defined as a disease gene for MMIHS and its role in establishing normal smooth muscle cytoskeletal–contractile coupling is suggested and conserved function of LMOD1 in human and mice is demonstrated.
Abstract: Megacystis microcolon intestinal hypoperistalsis syndrome (MMIHS) is a congenital visceral myopathy characterized by severe dilation of the urinary bladder and defective intestinal motility. The genetic basis of MMIHS has been ascribed to spontaneous and autosomal dominant mutations in actin gamma 2 (ACTG2), a smooth muscle contractile gene. However, evidence suggesting a recessive origin of the disease also exists. Using combined homozygosity mapping and whole exome sequencing, a genetically isolated family was found to carry a premature termination codon in Leiomodin1 (LMOD1), a gene preferentially expressed in vascular and visceral smooth muscle cells. Parents heterozygous for the mutation exhibited no abnormalities, but a child homozygous for the premature termination codon displayed symptoms consistent with MMIHS. We used CRISPR-Cas9 (CRISPR-associated protein) genome editing of Lmod1 to generate a similar premature termination codon. Mice homozygous for the mutation showed loss of LMOD1 protein and pathology consistent with MMIHS, including late gestation expansion of the bladder, hydronephrosis, and rapid demise after parturition. Loss of LMOD1 resulted in a reduction of filamentous actin, elongated cytoskeletal dense bodies, and impaired intestinal smooth muscle contractility. These results define LMOD1 as a disease gene for MMIHS and suggest its role in establishing normal smooth muscle cytoskeletal-contractile coupling.
113 citations
TL;DR: Current best practice for antenatal management will be discussed and Prediction of other aetiologies for the megacystis is less accurate but includes primary reflux, cloacal plate, urethral duplication and megacystic microcolon in the differential diagnosis.
Abstract: Ultrasound routinely identifies the fetal bladder from 10 weeks of gestation. Understanding the normal embryology of the fetal bladder forms the basis of understanding the mechanisms for pathology. Early onset megacystis <12 mm (maximum diameter) frequently regresses spontaneously however when associated with other structural abnormalities 40% are chromosomally abnormal. Survival in this group is rare and the underlying histopathology is of urethral fibrostenosis. Second and third trimester megacystic indicates a heterogenous group where a precise antenatal diagnosis may be impossible. A distended thick wall bladder associated with a dilated posterior urethra and oligohydramnios is pathonemonic of posterior urethral valves; without this combination of ultrasound signs the underlying pathology is less certain. Prediction of other aetiologies for the megacystis is less accurate but includes primary reflux, cloacal plate, urethral duplication and megacystic microcolon in the differential diagnosis. Robust published data is currently unavailable to define appropriate management for individual cases of megacystis. Therefore current best practice for antenatal management will be discussed.
92 citations
TL;DR: A review article summarizes the current knowledge of the aforementioned entities of variant HD, and recommends conservative treatments such as laxatives and enema are sufficient in most intestinal neuronal dysplasia cases.
72 citations
Related Topics (5)
Performance Metrics
| Year | Papers |
|---|---|
| 2021 | 6 |
| 2020 | 12 |
| 2019 | 13 |
| 2018 | 16 |
| 2017 | 10 |
| 2016 | 5 |