Regulation of nerve growth and patterning by cell surface protein disulphide isomerase.

Contact repulsion of growing axons is an essential mechanism for spinal nerve patterning. In birds and mammals the embryonic somites generate a linear series of impenetrable barriers, forcing axon growth cones to traverse one half of each somite as they extend towards their body targets. This study shows that protein disulphide isomerase provides a key component of these barriers, mediating contact repulsion at the cell surface in chick half-somites. Repulsion is reduced both in vivo and in vitro by a range of methods that inhibit enzyme activity. The activity is critical in initiating a nitric oxide/S-nitrosylation-dependent signal transduction pathway that regulates the growth cone cytoskeleton. Rat forebrain grey matter extracts contain a similar activity, and the enzyme is expressed at the surface of cultured human astrocytic cells and rat cortical astrocytes. We suggest this system is co-opted in the brain to counteract and regulate aberrant nerve terminal growth.

The mass effect of a slowly growing GIST.

Gastrointestinal stromal tumours (GISTs) are typically defined as solid masses arising from the GI tract, most commonly from the stomach and small intestine. They seldom present in a cystic form. Management of cystic masses arising from the GI tract may pose a diagnostic predicament. We had one such case that presented itself with complaints of a slow growing intra-abdominal mass. An ultrasound scan demonstrated a thick-walled cystic lesion arising from the pelvis. Further imaging evaluations in the form of a CT scan revealed a complex large cystic mass arising from left upper quadrant (see Figure 1). Due to the uncertainty of origin of this mass and lack of invasion or lymphadenopathy, it was thought to be benign. After a multidisciplinary meeting, it was concluded that an urgent surgical excision of this benign mass was the best treatment. The surgical treatment of which entailed a 10 hours surgery to resect this 10 kg lesion, which comprised 7 L fluid and 3 kg solid mass. Histopathology aided in the diagnosis of this lesion as a CD117-positive and DOG1-positive GIST.

Acute gastric outlet obstruction secondary to exclusive paraoesophageal small bowel herniation: a case report.

INTRODUCTION: Herniation of abdominal viscera into the thorax may occur as a consequence of abnormal defects in the diaphragm. In adults, the most common condition relates to herniations through a weakened crural orifice via which the oesophagus normally traverses. These hiatus hernias are classified as types I-IV depending on the extent of visceral involvement. CASE REPORT: We present here a case of type IV hiatus hernia with massive mediastinal herniation of the small bowel, yet remarkable in that the stomach itself remained completely intra-abdominal. Gastric outlet obstruction occurred as a consequence of extrinsic proximal small bowel compression. DISCUSSION: To our knowledge this is the first reported case of paraoesophageal hernia exclusively involving small bowel, without involving any part of the stomach, and yet causing gastric outlet obstruction.

Transthoracic repair of an incarcerated diaphragmatic hernia using hexamethylene diisocyanate cross-linked porcine dermal collagen (Permacol).

It is the general surgeon who commonly repairs paraesophageal hernias nowadays, and they are repaired laparoscopically, making the performance of thoracotomy relatively rare. Whether to use prosthetic materials to repair the hiatus is still under debate, as is the question of which material to use, if any. We report a case of a 38-year-old man who had a large, incarcerated paraesophageal hernia. He had a past history of extensive abdominal surgery for exomphalos, which rendered any abdominal surgical approach a high-risk procedure. We therefore decided to proceed with thoracotomy and repair of the hiatus with hexamethylene diisocyanate (HMDI) cross-linked porcine dermal collagen. He made a good recovery with no complications.

The decision to operate: role of integrated computed tomography positron emission tomography in staging oesophageal and oesophagogastric junction cancer by the multidisciplinary team.

OBJECTIVE: Our objective was to assess the role of fusion positron emission tomography-computed tomography (PET-CT) in staging patients for minimally invasive oesophagectomy (MIO) with potentially resectable disease from the perspective of a multidisciplinary team (MDT) deciding on operability with conventional staging investigations. METHODS: Fifty consecutive patients presenting with potentially operable oesophageal or oesophagogastric junctional tumours were staged with computed tomography (CT) and endoluminal ultrasound (EUS). The MDT categorised patients as group A (n=33; CT N0M0) or group B (n=17; CT N1/possible M1). All patients underwent FDG PET-CT. Patients with localised disease (at T3), including single level N1 disease on PET-CT, were deemed suitable for induction chemotherapy followed by surgery. RESULTS: PET-CT re-categorised 12% of patients as inoperable on grounds of distant metastases (four in group A, two in group B). Five patients did not proceed to resection for other reasons. Two had metastatic disease at thoracoscopy. Resection specimens (n=37) contained 24 nodes (median). Compared with pN status, positive predictive value of PET-CT was 40% and negative predictive value was 43%. The expected PET-CT N1 group had the highest mean number of involved nodes. Median survival for all patients (n=50) was 31.9 months for group A compared with 17.3 months for group B (not statistically significant). There was no significant difference between patients who were PET-CT N0 or N1 in survival or disease-free survival in patients undergoing surgery (n=37). CONCLUSIONS: PET-CT informs the MDT decision to operate in avoiding futile surgery in stage IV disease or widespread nodal disease. In this study, overall PET-CT N1 status has low positive and negative predictive value for overall pN status.

Transgastric drainage of the oesophagus: managing difficult oesophageal injuries.

We describe a technique for maintaining patency of the injured or repaired oesophagus while providing vacuum drainage of the oesophageal lumen. A small midline laparotomy is performed. A lubricated 36F soft chest drain (pull-through end) is introduced into the oesophagus using a percutaneous endoscopic gastrostomy (PEG) set, and pulled out through the stomach wall. The drain is brought out through the abdominal wall and the stomach is anchored to the peritoneum. The transgastric drain is positioned across the oesophageal defect. A feeding jejunostomy is placed. Decontamination and drainage of the chest is performed if the patient's condition allows. The patient takes sterile water by mouth to maintain drain patency, with -10 cm H(2)O suction applied. We have used this drainage procedure in seven patients (Boerhaave's syndrome (n=4), operative injury (n=3)). In five patients with injuries close to the oesophagogastric junction, this method was used as an adjunct to primary repair. There were no deaths; the oesophageal defect healed in all patients without stricture. All patients are swallowing normally at follow-up. This procedure is presented as an option for patients who are unfit for primary repair, or whose primary repair would benefit from efficient drainage and protection.