Gastric Ectopic Pancreas With Pseudocyst Formation Causing Gastric Outlet Obstruction.

Ectopic pancreas is a rare entity referring to the presence of pancreatic tissue at an anatomic location distinct from the pancreas. Ectopic pancreatic lesions in the stomach present a diagnostic challenge because the lack of distinguishing imaging and endoscopic features make them difficult to differentiate from other types of submucosal lesions. We report a case of ectopic pancreas presenting as a gastric antral mass with a unique combination of rare complications: chronic pancreatitis and pseudocyst formation causing gastric outlet obstruction. This case highlights complications that can occur from ectopic pancreatic lesions and the challenges of diagnosing ectopic pancreas.

Novel Investigation of the Deep Band of the Lateral Plantar Aponeurosis and Its Relationship With the Lateral Plantar Nerve.

BACKGROUND: We describe a thick fascial band arising from the medial aspect of the lateral plantar aponeurosis diving deep into the forefoot crossing over a branch of the lateral plantar nerve. Because a review of current literature resulted in limited and outdated sources, we sought to first determine the frequency of this fascial band and the location where it crosses the lateral plantar nerve and, second, discuss the clinical applications these anatomical findings could have. METHODS: 50 pairs of cadaveric feet (n = 100) were dissected to investigate for presence of the fascial band and its interaction with the lateral plantar nerve. Images were taken of each foot with the fascial band. ImageJ was used to take 2 measurements assessing the relationship of the tuberosity of the base of the fifth metatarsal to where the nerve crossed deep to the fascial band. RESULTS: Overall, 38% of the feet possessed the fascial band. It was found unilaterally in 10 pairs and bilaterally in 14 pairs. On average, the point at which the lateral plantar nerve passed deep to the fascial band was 2.0 cm medial and 1.7 cm anterior to the tuberosity of the base of the fifth metatarsal. CONCLUSION: When present, the deep band of the lateral plantar aponeurosis (PA) was consistently found to be crossing the lateral plantar nerve. The discovery of the location where this most commonly occurs has not been previously reported and adds an interesting dimension that elevates an anatomical study to one that has clinical potential. CLINICAL RELEVANCE: The established target zone gives a precise location for where the relationship between the deep band of the lateral PA and the lateral plantar nerve exists when evaluating the foot. The target zone provides a potential springboard for future investigations concerning said relationship clinically.

Characterization of neuromas in peripheral nerves and their effects on heterotopic bone formation.

The formation of neuromas involves expansion of the cellular components of peripheral nerves. The onset of these disorganized tumors involves activation of sensory nerves and neuroinflammation. Particularly problematic in neuroma is arborization of axons leading to extreme, neuropathic pain. The most common sites for neuroma are the ends of transected nerves following injury; however, this rodent model does not reliably result in neuroma formation. In this study, we established a rodent model of neuroma in which the sciatic nerve was loosely ligated with two chromic gut sutures. This model formed neuromas reliably (∼95%), presumably through activation of the neural inflammatory cascade. Resulting neuromas had a disorganized structure and a significant number of replicating cells. Quantification of changes in perineurial and Schwann cells showed a significant increase in these populations. Immunohistochemical analysis showed the presence of ß-tubulin 3 in the rapidly expanding nerve and a decrease in neurofilament heavy chain compared to the normal nerve, suggesting the axons forming a disorganized structure. Measurement of the permeability of the blood-nerve barrier shows that it opened almost immediately and remained open as long as 10 days. Studies using an antagonist of the ß3-adrenergic receptor (L-748,337) or cromolyn showed a significant reduction in tumor size and cell expansion as determined by flow cytometry, with an improvement in the animal's gait detected using a Catwalk system. Previous studies in our laboratory have shown that heterotopic ossification is also a result of the activation of neuroinflammation. Since heterotopic ossification and neuroma often occur together in amputees, they were induced in the same limbs of the study animals. More heterotopic bone was formed in animals with neuromas as compared to those without. These data collectively suggest that perturbation of early neuroinflammation with compounds such as L-748,337 and cromolyn may reduce formation of neuromas.

Cell-Based Gene Therapy System for Delivering BMPs.

The use of an adenoviral vector to transduce cells allows for certain secreted proteins or growth factors to be generated in vivo in eukaryotic cells with accurate posttranslational processing. The use of transduced cells eliminates viral toxicity, allows for targeted expression of the secreted factor at a specific site, and ensures that the therapy will be turned off when the cells are cleared by the organism. Here we describe the delivery system which utilizes cells transduced with a non-replicating adenovirus containing bone morphogenetic protein 2 (BMP-2) in the E1 region of the cassette. With this method of delivery, small amounts of the protein can incite de novo bone formation.

Characterization of Brown Adipose-Like Tissue in Trauma-Induced Heterotopic Ossification in Humans.

Heterotopic ossification (HO), the abnormal formation of bone within soft tissues, is a major complication after severe trauma or amputation. Transient brown adipocytes have been shown to be a critical regulator of this process in a mouse model of HO. In this study, we evaluated the presence of brown fat within human HO lesions. Most of the excised tissue samples displayed histological characteristics of bone, fibroproliferative cells, blood vessels, and adipose tissue. Immunohistochemical analysis revealed extensive expression of uncoupling protein 1 (UCP1), a definitive marker of brown adipocytes, within HO-containing tissues but not normal tissues. As seen in the brown adipocytes observed during HO in the mouse, these UCP1+ cells also expressed the peroxisome proliferator-activated receptor γ coactivator 1α. However, further characterization showed these cells, like their mouse counterparts, did not express PR domain containing protein 16, a key factor present in brown adipocytes found in depots. Nor did they express factors present in beige adipocytes. These results identify a population of UCP1+ cells within human tissue undergoing HO that do not entirely resemble either classic brown or beige adipocytes, but rather a specialized form of brown adipocyte-like cells, which have a unique function. These cells may offer a new target to prevent this unwanted bone.