MMP expression in leaking filtering blebs and tears after glaucoma filtering surgery.

OBJECTIVE: Glaucoma filtering surgery may be compromised by cystic blebs which develop more frequently when anti-metabolites are used to arrest wound healing. Matrix metalloproteinases (MMPs) and the naturally occurring tissue inhibitors of metalloproteinases (TIMPs) are essential in connective tissue remodeling and wound healing. This study aimed to determine whether filtering blebs display increased expression of MMP-2, MMP-9, TIMP-1 and TIMP-2, and whether it is reflected in tear fluid. METHODS: Tissue samples from leaking blebs (n = 5) and control conjunctiva (n = 5) were evaluated by immunohistochemistry for MMP-2, MMP-9, TIMP-1 and TIMP-2. Tear fluid was collected from 12 patients (12 eyes) with cystic blebs and ten patients (ten eyes) with flat blebs following trabeculectomy with Mitomycin C applied and 16 controls. MMP levels were evaluated by zymography and TIMP levels by Western blot analysis. RESULTS: Conjunctival tissue was obtained from five eyes with cystic leaking blebs and five control eyes undergoing cataract surgery. More extensive MMP-2 and MMP-9 expression was found in the epithelial and stromal layers of blebs than in control conjunctiva. TIMP-1and TIMP-2 were expressed in all layers of the blebs, but only in the epithelium of control conjunctiva. MMP-2 and proMMP-2 activity in tears from eyes with flat blebs was significantly higher than that of controls, while activity in tears of eyes with cystic blebs was significantly higher than in those with flat blebs. There was no difference in MMP-9 activity between tears of control and post-filtering surgery eyes. CONCLUSIONS: Increased MMPs and TIMPs expression is associated with the formation of filtering blebs, suggesting involvement of MMPs in bleb remodeling. MMP-2 and ProMMP-2 levels in tear fluid may be markers for bleb configuration.

Matrix metalloproteinases in rectal mucosa, tumour and plasma: response after preoperative irradiation.

BACKGROUND: In rectal cancer treatment, preoperative radiotherapy has led to reduction of local recurrence, but it is associated with morbidity and increased risk for secondary tumours. Matrix metalloproteinases (MMPs) are associated with tumour progression through tissue remodeling. The aim of this study was to investigate tissue remodeling after preoperative radiotherapy and to explore possible correlations with clinical outcome. MATERIALS AND METHODS: Ninety-one patients scheduled for rectal cancer surgery were included; 49% received preoperative radiotherapy three-field treatment, 5 x 5 Gy. Blood samples and biopsies from tumour and adjacent mucosa were taken during surgery. Biopsies and plasma were assayed with ELISA for MMP-1, MMP-2 and MMP-9. Clinical outcome was reviewed focusing on infections, perineal healing, fistula formation, anastomotic dehiscence, small bowel obstruction, local recurrence and distant metastases. RESULTS: Compared to non-irradiated mucosa, MMP-2 (p < 0.0001), MMP-1 (p = 0.03) and MMP-9 (p = 0.04) were significantly higher in irradiated normal mucosa. Tumour tissue had higher levels of MMP-2 if irradiated (p < 0.0001). A correlation between MMP-2 levels and wound infection (p = 0.02) as well as fistula formation (p = 0.04) was found. MMP-1 in mucosa (p = 0.02) and tumour (p = 0.04) were higher in patients developing distant metastases. Plasma levels were not influenced by irradiation, but MMP-2 was higher in patients who were later developing distant metastases (p = 0.007). CONCLUSIONS: Extracellular matrix remodeling after radiotherapy seems to be correlated to postoperative morbidity; MMP-2 is associated with both wound infections and fistula formation. High levels of MMP-1 in tumour and mucosa as well as MMP-2 in plasma may be correlated to risk of developing distant metastases.

The wound amylase concentration in the prediction of pharyngocutaneous fistula.

Pharyngocutaneous fistula (PCF) is not uncommon after laryngeal surgery. Because it leads to prolonged hospitalization and increased patient morbidity, it is important to predict the formation of fistula. We studied the wound amylase concentrations of 87 consecutive laryngectomized patients. The PCF rate was 11.5% in this series. The amylase levels in patients with PCF begin to elevate significantly on the third, fourth, and fifth postoperative days. Our data indicate that increase in the wound amylase levels seems to be a significant predictor of PCF, and this should alert the surgeon for the presence of fistula.

Wound amylase estimation and the prediction of pharyngocutaneous fistulae.

Pharyngocutaneous fistula is a common complication after major head and neck surgery. In this study it was possible to predict fistula formation as early as the second postoperative day, using serial measurements of the amylase concentration in wound drainage. Wound amylase estimation may be used to help avoid major pharyngocutaneous fistulae by providing an 'early warning' and allowing modification of the postoperative feeding regimen in certain situations.

Low plasma renin concentration in patients with Meniere's disease (preliminary report).

Endolymphatic hydrops is the histopathologic hallmark of Meniere's disease. The cause of excess inner ear fluid is unknown, but the possibility of a systemic abnormality of fluid-solute regulation has been considered. One indicator of systemic fluid and electrolyte balance is the enzyme renin. Plasma renin levels were measured in patients with a clinical diagnosis of Meniere's disease and compared to a group of patients who did not have Meniere's disease. The mean plasma renin concentration of patients with Meniere's disease was statistically lower than that of the other subjects. The study's results are consistent with a systemic abnormality in fluid and solute regulation in some patients with M eniere's disease, leading to abnormal expansion of the extracellular fluid volume, and possibly contributing to endolympathic hydrops.

Enhancement of intestinal sucrase activity in experimental diabetes: the role of intraluminal factors.

Experimental diabetes alters intestinal mucosal function in a variety of ways including the enhancement of both active transport processes and the activity of brush-border hydrolases. These effects could result from changes in either intraluminal factors (food, bile, pancreatic enzymes) or extraluminal factors (blood flow, hormones, nervous impulses). To determine the role of intraluminal factors we studied the effect of diabetes on segments of jejunum completely excluded from luminal continuity, but with intact blood and nerve supply. Three weeks after construction of Thiry-Vella fistulas in rats, diabetes was induced with streptozotocin. Five days later sucrase activity was measured in both the excluded segment and in the proximal jejunum. Exclusion alone resulted in a 77 per cent decrease in mucosal protein content with no change in sucrase specific activity suggesting simply a diminished number of mucosal cells. Diabetes increased the specific activity of sucrase from 0.0643 mumoles per minute per milligram of protein plus or minus 0.0077 (SEM) to 0.1074 plus or minus 0.0182 (P smaller than 0.05) in the proximal jejunum and from 0.0467 plus or minus 0.0047 to 0.1040 plus or minus 0.0191 (P smaller than 0.02) in the excluded segment. These results provide conclusive evidence that the diabetic enhancement of sucrase activity is independent of intraluminal factors and must be the consequence of extraluminal changes.