Analysis of gene expression in the tumor-associated macrophage

INTRODUCTION

The tumor-associated macrophage (TAM) is at the front line of the host's defense against malignancy and provides an attractive target for immune-modulatory therapy. However, factors present within the tumor microenvironment can alter macrophage phenotype, preventing its cytotoxic activity and reducing its susceptibility to interferon-gamma and lipopolysaccharide-mediated stimulation.

METHODS

Macrophages were isolated from subcutaneous B16 melanoma tumors implanted in C57 BL/6 mice. Wound macrophages were harvested from subcutaneously-implanted PVA sponges, and resting peritoneal macrophages were harvested by peritoneal lavage. Gene expression was analyzed using an Atlas cDNA array (Clontech, Mountain View, CA).

RESULTS

TAM demonstrated a pattern of gene expression distinct from both wound and peritoneal macrophage. There is an increase in proliferation-associated genes and in genes encoding the ultrastructural proteins cofillin, zyxin, and vimentin more commonly associated with fibroblast-like cells. In addition, an observed decrease in expression of the CD14 gene, and increase in inhibitory pathways including osteopontin and its receptor CD44, the inositol 1,4,5-triphosphate receptor, and the receptors for interleukin-4 and granulocyte monocyte-colony stimulating factor could explain the resistance of TAM to lipopolysaccharide-mediated stimulation. There was also a significant decrease in the expression of the interferon-gamma second messenger, IRF-1.

CONCLUSIONS

This study has identified a number of pathways involved in the suppression of TAM function. Targeting of these pathways may allow for the generation of more effective immune-modulatory anti-neoplastic therapy.

Recurrent trigeminal neuralgia secondary to Teflon felt

The authors present a case of a 45-year-old man with recurrent trigeminal neuralgia twelve years after microvascular decompression. The patient underwent surgical reexploration of the trigeminal nerve. A piece of hardened Teflon felt was found piercing a hole through the trigeminal nerve. No other compression of the nerve was found. Removal of the Teflon felt resolved the neuralgia. To the authors knowledge this is the first report of recurrent trigeminal neuralgia due to such a mechanism. This case emphasises the need for further improvement of the surgical technique for microvascular decompression of the trigeminal neuralgia.

Postoperative complications due to a retained surgical sponge

Retained surgical sponge or glossypiboma is a relatively common occurrence; however, surgeons may not report these events for fear of litigation and adverse publicity. We report postoperative complications in three cases due to retained surgical sponges. The first case, a 26-year-old woman, presented with gastric outlet obstruction due to the sponge obstructing the pyloric canal three weeks following cholecystectomy, which was completely relieved following endoscopical removal of the sponge. The second case, a 32-year-old woman, presented with repeated attacks of intestinal obstruction following cholecystectomy and tubal ligation and was treated with surgical removal of the sponge. The third patient, a 40-year-old woman, presented with features of colonic obstruction following hysterectomy. Colonoscopy revealed a partial migration of the sponge through the colonic wall and on laparotomy, she was found to have multiple internal fistulae between the small and large intestines, all occurring around the inflammation caused by the retained sponge.

The potential of microscopic sterile sponge particles to induce foreign body reaction

The sterile sponges may lose a significant amount of lint during their routine use in surgery, which is usually neglected. We designed an experimental model to evaluate the potential of sterile sponges to lose lint and to induce foreign body reaction in surgically created wounds. In 15 Wistar rats, separate subcutaneous pockets were created. Left-sided pockets were temporarily packed with sterile sponges, while the right-sided pockets remained empty. All the pockets were then irrigated with sterile saline. The presence of microscopic sponge particles was evaluated in the irrigation materials. After 4 weeks, the presence of inflammation and foreign body reaction were evaluated histologically. Microscopic sponge remnants were present in 14 of 15 samples collected from the left sides. The presence of foreign body giant cells with ingested sponge particles and formation of well-defined foreign body granulomas were observed only in samples collected from the left sides. A statistically significant difference was observed between the two sides when the intensity of inflammation was graded (P= 0.012). Cotton sponges used in surgery are shown to have a potential of losing invisible microscopic particles that have a potential to induce foreign body reaction.

Transmural migration of surgical sponge evacuated by defecation: mimicking an intraperitoneal gossypiboma

The spontaneous defecation of the surgical retained sponge is very rare. Here, we report a case of migrating surgical sponge that was retained in the colon and it was evacuated by defecation.

Cellular proliferation, differentiation and apoptosis in polyether-polyurethane sponge implant model in mice

The integration of implanted material to host organism requires spatial and temporal organization of several cellular processes, such as proliferation, differentiation and apoptosis. Despite the clinical relevance of these processes, there is little information regarding the sequence of such events in synthetic matrices. Here, we present a combination of techniques used to characterize the fibrovascular response in subcutaneous polyether-polyurethane sponge implants in mice at days 4, 7, 10 and 14 postimplantation. The AgNOR technique was modified and used as a surrogate marker for proliferating and activated cells invading the implant. The number of AgNOR-stained cells increased progressively from day 4 (606+/-76) to day 14 (2146+/-71) postimplantation. The number of TUNEL-positive (apoptotic index) cells also increased progressively from day 4 (459+/-40) to day 14 (1157+/-119) postimplantation. However, the ratio of TUNEL-labeled/proliferating cells had its highest peak in the early phase of the process remaining stable until day 14. Using Picrosirius staining it was shown that thin collagen increased from day 4, peaking at day 10 and falling markedly at day 14, whereas dense collagen increased progressively during the whole period. These experiments hold potential to investigate not only distinct phases of tissue repair induced by synthetic matrices but also to study underlying mechanisms involved.

Obstructive jaundice due to a textiloma mimicking a common bile duct stone

A foreign body is a rare cause of obstructive jaundice. We report a 19-year-old woman with jaundice caused by a surgical gauze in the common bile duct (CBD). Four yours earlier, she had undergone a cholecystectomy and drainage for hydatid disease of the liver. Her postoperative course was complicated by a biliary fistula that healed after 50 days. She now presented with obstructive jaundice of 2 weeks' duration. Magnetic resonance cholangiopancreatography (MRCP) showed a signal-void mass, consistent with a CBD stone. Surgical exploration of the CBD revealed a surgical gauze as the cause of the obstruction. To the best of our knowledge, this is the first case of a surgical gauze obstructing the CBD requiring surgical removal.

Gossypiboma: a report of 2 cases

BACKGROUND

Retention of surgical sponges in body cavities (gossypiboma) is preventable. It is probably under reported, may be for medicolegal reasons. We report 2 cases we have managed, one at a tertiary medical centre, and the other, at a private clinic in Port Harcourt, in order to re-awaken the awareness of its occurrence and make a plea for caution during surgery.

METHODS

The case notes of patients treated surgically over the period between 1995 and 2004 were reviewed for cases of retained surgical sponges.

RESULTS

Two cases were identified over the period 1995 to 2004. One had presented acutely while the second case presented in a sub-acute manner. Both required re-exploration and retained sponges were retrieved.

CONCLUSION

It may not be possible to eradicate the occurrence of retained sponges in the body but it can definitely be minimized, thus saving many patients from the associated agony.

Case report: a gossypiboma in the shoulder

We present the case of a 15-year-old boy who underwent shoulder surgery for repair of a Bankart lesion after dislocation of his right shoulder. A compress was left in the surgical wound. This case is presented to highlight an important pitfall in the diagnosis of gossypiboma (foreign body reaction): when the wires of a compress are visualized on X-ray, beware of the fact that it is possibly located inside the body. The diagnosis of an abscess was made by ultrasound. The compress wires were visualized on radiographs.

Lintene granuloma following microvascular decompression mimicking a cerebellopontine angle tumour

We describe a case of foreign body granuloma caused by lintene (cotton gauze), placed during microvascular decompression of the fifth nerve for trigeminal neuralgia. At presentation, the clinical and radiological findings were suggestive of a tumor. This is only the second case in the literature of a foreign body granuloma occurring owing to the placement of a lintene pledget during microvascular decompression.

FDG PET CT features of an intraabdominal gossypiboma

Retained surgical sponge or gossypiboma in the abdominal cavity is an infrequent but serious surgical complication that may lead to medicolegal problem. The incidence of a surgical sponge retained at operation is difficult to estimate, but it has been reported as 1 in 100 to 3000 for all surgical interventions and 1 in 1000 to 1500 for intraabdominal operations. The natural evolution of a retained sponge, if aseptic, is to cause a foreign body reaction, followed by organization to form a foreign body granuloma, which may mimic a soft tissue neoplasm. Although features of CT and MR imaging of gossypibomas have been documented in the literature, they have often been misinterpreted preoperatively owing to the rarity of gossypibomas in daily clinical practice and to the low index of clinical suspicion. We report the FDG PET CT findings of a 42-year-old woman who had undergone cesarean sections twice previously, with an intraabdominal gossypiboma found incidentally in a routine health examination. We hope the PET CT findings in this case offer us useful adjunctive information to conventional imaging studies in the diagnosis of gossypiboma.

Electronic tagging of surgical sponges to prevent their accidental retention

BACKGROUND

The inadvertent "loss" of surgical sponges, towels, and instruments remains an unsolved problem. The means of preventing this mishap involve an inventory of all implements going in and coming out of the surgical wound, supplemented by a careful search. This work describes a different approach to this problem: tagging articles placed into the wound with markers able to be rapidly detected electronically.

METHODS

Surgical sponges were tagged with either active targets or inert, dummy targets and placed in different locations within the body of 50 cadavers. Using a device we constructed, blinded readings were performed to test the accuracy of detecting retained sponges.

RESULTS

A total of 600 readings were made in 50 cadavers, 300 of active targets and 300 of inert, dummy targets, indistinguishable in appearance. The active markers were detected with 100% accuracy. There were no false positive detections of the dummy tags.

CONCLUSION

The present work demonstrates the feasibility of detecting retained surgical sponges by electronic means blinded to whether the tag contained an active or inert marker.

A 40-year-old gossypiboma (foreign body granuloma) mimicking a malignant femoral surface tumor

The patient was a 61-year-old man who developed gossypiboma of the left thigh and femur resulting in the imaging appearances of a malignant surface tumor. He had a past history of surgery on the left femur for open fracture 40 years previously. Radiographs and CT showed a soft tissue mass with osteolysis and periosteal thickening of the left femur. On MRI, the mass showed heterogeneous signal intensity with contrast enhancement at the periphery, suggesting a malignancy. 99mTc-HMDP bone scintigraphy showed a faint ring-like uptake, but thallium -201 scintigraphy did not show any uptake in the tumor. An extensive intralesional excision was performed. Postoperative histopathological examination showed a fibrous foreign body with reactive changes. There were neither viable cells nor atypical giant cells around the foreign body. No malignant change was evident. Based on surgical and histopathological examinations, the tumor was finally diagnosed as gossypiboma related to a retained surgical sponge.