Biomedical subjects

Amina Bhatia

Publications and source records attributed to Amina Bhatia.

5 recordsLinked to original sources

PubMed2006

Left-sided gastroschisis.

Gastroschisis is a periumbilical, abdominal wall defect arising to the right of the umbilicus. We describe the clinical course of a left-sided gastroschisis in a term female born at 39 weeks' gestation. To our knowledge, there have been only 14 left-sided abdominal wall defects reported in the literature. We discuss our case and review the literature to try to determine if there is any clinic difference between right- versus left-sided lesions to make recommendations as to management.

Colon↗

PubMed2005

Video-assisted thoracoscopic division of vascular rings in pediatric patients.

Vascular rings are usually repaired via left thoracotomy. We report our series of pediatric patients with vascular rings that were repaired thoracoscopically. From February 2002 to September 2004, 13 patients underwent video-assisted thoracoscopic surgical techniques (VATS) division of their vascular ring. Chest magnetic resonance arterography (MRA) and/or computed tomographic arteriography (CTA) were used to evaluate the vascular ring in most patients. Patients were chosen for VATS repair based on surgeon's choice and type of vascular ring. Data are expressed as mean +/- SD. The Children's Healthcare of Atlanta Institutional Review Board approved this retrospective chart review. Age and weight was 1.5 +/- 1.8 years (range: 4 months - 17 years) and 16.0 +/- 12.5 kg (range: 6.0 - 22.1 kg), respectively (n = 13). Associated diseases included congenital heart disease (n = 2). Symptoms included respiratory complaints (n = 6), dysphagia (n = 2), dysphagia and shortness of breath (n = 1), pneumonia (n = 2), tracheal deviation (n = 1), and one patient was asymptomatic. Vascular ring types included double aortic arch (n = 4) and right aortic arch with an aberrant left subclavian artery and a left ligamentum arteriosum (n = 9). Operating time was 70 +/- 20 minutes (range: 46 - 122 minutes). One patient had to be opened because of a large arch. Length of stay was 1.9 +/- 0.9 days (range: 1 - 3 days). There were no complications, and all patients improved clinically at follow-up. Thoracoscopic repair of certain types of vascular rings seems to be safe and effective in children. More patients, however, need to be studied.

Abnormalities, Multiple↗

PubMed2004

Multifaceted pancreatic mesenchymal control of epithelial lineage selection.

Mouse pancreatic development is critically dependent on epithelial-mesenchymal interactions. The pancreas differs from other epithelial-mesenchymal organs in that the epithelium gives rise to both epithelial exocrine cells and non-epithelial endocrine cells. We studied the nature of the interactions between the epithelium and mesenchyme with respect to the decision between exocrine and endocrine lineages. We show here a tripartite influence of mesenchyme on the developing epithelium. First, close proximity or contact of mesenchyme with the epithelium induces exocrine differentiation. Second, this mesenchymal proximity to the epithelium suppresses endocrine differentiation. Third, mesenchyme has an overall enhancing effect on the degree of insulin differentiation, suggesting a pro-endocrine effect in those epithelial cells at a distance from the mesenchyme. Proximity or contact between the mesenchyme and epithelium appeared to be necessary for the pro-exocrine effects of mesenchyme. We found that, in a co-culture system, NIH3T3 cells were able to substitute for mesenchyme in exocrine induction as well as in both the endocrine induction and endocrine inhibition, implying that the responsible molecules are not unique to pancreatic mesenchyme. Laminin appears to be a key molecule mediating the epithelial-mesenchymal interactions that lead to exocrine differentiation, since inhibition of laminin expression resulted in blockage of the pro-exocrine induction of mesenchyme.

Animals↗

PubMed2003

A role for sonic hedgehog signaling in the pathogenesis of human tracheoesophageal fistula.

BACKGROUND/PURPOSE: Many theories of the pathogenesis of esophageal atresia with tracheoesophageal fistula (EA/TEF) have been proposed, but no specific mechanism has been demonstrated. The authors previously reported data suggesting a respiratory origin of the fistula tract in the rat model and in humans. Sonic hedgehog (Shh) "knockout" mice have the VACTERL association, and thus it was hypothesized that defects in Shh signaling may exist in the human neonatal EA/TEF fistula tract. METHODS: With IRB approval, human proximal esophageal pouch and distal fistula samples were removed at the time of standard repair of EA/TEF in accordance with what the surgeons deemed appropriate in preparation for anastomosis. Tissues were processed for HE, reverse-transcriptase polymerase chain reaction (RT-PCR), and immunohistochemistry. Normal embryonic lung cDNA was used as a positive control for the RT-PCR reactions. RESULTS: As expected, Shh was present by immunohistochemistry in the proximal esophageal pouch, but was specifically absent in the distal fistula tract. Gli-1, -2, and -3 (all intracellular mediators of Shh signaling) were present in the proximal pouch and distal esophagus by RT-PCR. CONCLUSIONS: The absence of Shh signaling in the developing fistula tract of the human neonate was surprising given that Shh normally is present in esophagus and other gut components. These results support the conclusion that the fistula tract is not an esophaguslike structure, despite both its histologic appearance and its use as an esophageal replacement. Also, like in Shh-null mutant mice, aberrant Shh signaling may play a critical role in the pathogenesis of EA/TEF in humans.

Abnormalities, Multiple↗

PubMed2002

Glucagon is required for early insulin-positive differentiation in the developing mouse pancreas.

The embryonic pancreas is thought to develop from pluripotent endodermal cells that give rise to endocrine and exocrine cells. A key guidance mechanism for pancreatic development has previously been found to be epithelial-mesenchymal interaction. Interactions within the epithelium, however, have not been well studied. Glucagon is the earliest peptide hormone present at appreciable levels in the developing pancreatic epithelium (embryonic day [E]-9.5 in mouse). Insulin accumulation begins slightly later (E11 in mouse), followed by a rapid accumulation during the "second wave" of insulin differentiation ( approximately E15). Here we found that blocking early expression and function of glucagon, but not GLP-1, an alternate gene product of preproglucagon mRNA, prevented insulin-positive differentiation in early embryonic (E11) pancreas. These results suggest a novel concept and a key role for glucagon in the paracrine induction of differentiation of other pancreatic components in the early embryonic pancreas.

Animals↗