Changes in Gelatinase Activity in the Gastrointestinal Tract After Anastomotic Construction in the Ileum or Colon

PURPOSE The strength of the uninjured and anastomosed intestinal wall is determined by its submucosal connective tissue. Matrix degradation by matrix metalloproteinases may result in loss of strength. It is known that anastomotic construction leads to up-regulation of matrix metalloproteinase activity in the wound area, but no quantitative data are available as to the extent of this effect throughout the intestinal wall. This study was designed to quantitate changes in gelatinolytic activity in the intestine after anastomotic construction in the ileum or colon. METHODS An anastomosis was constructed in the distal ileum or distal colon of rats, and animals were killed after one or three days. Tissue samples (5 mm) were collected containing the suture line, its adjacent segments (2- × 5-mm in both directions) and at nine other, more distant, sites throughout the gastrointestinal tract. Similar samples were collected from nonoperated control rats. All samples were analyzed by quantitative gelatin zymography. RESULTS In control rats, the most prominent gelatinolytic activities were found at 80 kDa, thought to represent a nonspecific proteolytic activity, 60 kDa and 50 kDa, representing the proform and active form of matrix metalloproteinase-2, respectively. Activities were higher in the small bowel than in the large bowel. Anastomotic construction led to massive up-regulation of an activity at 105 kDa, and its dimer, believed to represent promatrix metalloproteinase-9. Matrix metalloproteinase-2 remained unaffected, whereas the activity of the 80 kDa protein was significantly (P < 0.05) reduced. Significantly increased matrix metalloproteinase-9 activity was found in the actual anastomotic segments and in the immediately adjacent tissue. Matrix metalloproteinase-9 activities in the anastomotic segments were highest at Day 1 in the ileum and at Day 3 in the colon. Anastomotic construction in the ileum or colon did not lead to any significant changes of any gelatinolytic activity at the more distant sites in the bowel wall. CONCLUSIONS Up-regulation of gelatinase activity after anastomotic construction in the intestine is caused by matrix metalloproteinase-9. Because the effect is local and not systemic, unwanted matrix degradation at distant sites seems unlikely. Supported by the Radboud University Nijmegen Medical Centre, Nijmegen, The Netherlands. Reprints are not available.     

Histologic multifocality of Tis, T1-2 breast carcinomas. Implications for clinical trials of breast-conserving surgery

Breast cancer multifocality was studied in mastectomy specimens by correlated specimen radiography and histologic techniques. The patients chosen for study were comparable to those eligible for breast-conserving surgical therapy. Two study groups, one with 282 invasive cancers (T1-2) and the other with 32 intraductal cancers, were selected from a group of 399 consecutive cases by omitting patients who were clearly, or very probably, not candidates for breast-conserving surgical therapy according to current trial criteria. Omitted patients included those with clinically and/or radiologically multifocal cancers and patients with tumor extension into the chest wall or skin (7%). Also excluded were the so-called diffuse invasive cancers (8%), the clinically and radiologically occult tumors (3%), and the invasive cancers larger than 5 cm (3%). Of the 282 invasive cancers, 105 (37%) showed no tumor foci in the mastectomy specimen around the reference mass. In 56 (20%) tumor foci were present within 2 cm, and in 121 (43%) tumor was found more than 2 cm from the reference tumor. In 75 (27%) the tumor foci beyond 2 cm were histologically noninvasive cancers, and in 46 cases (16%) they contained invasive cancers as well. A comparison between the group with reference tumors less than 2 cm and the group with reference tumors more than 2 cm in size showed no significant difference between the groups in terms of presence or absence of tumor foci or distance of tumor foci from the reference tumor. If the 264 invasive cancers in this series that were 4 cm or less in diameter had been removed with a margin of 3 to 4 cm, 7% to 9% of the patients would have had invasive cancer left in the remaining breast tissue, and 4% to 9% would have had foci of noninvasive cancer left in the remaining breast tissue. On the basis of the data on the distribution of tumor at different distances from the reference tumor, the current study estimates the expected rates of local recurrences after breast-conserving surgical procedures relative to the extensiveness of the excision. The possible impact of postoperative local radiation therapy on the rates of expected local recurrence is discussed.     

Kinetics of homocysteine metabolism after moderate alcohol consumption

BACKGROUND: Moderate alcohol consumption is associated with a decreased risk of cardiovascular disease. Because plasma homocysteine (tHcy) is considered an independent risk factor for cardiovascular disease and associated with alcohol consumption, the authors investigated the effect of moderate alcohol consumption on kinetics of plasma tHcy concentration, vitamin B status, and other parameters involved in tHcy metabolism. METHODS: Ten healthy men and nine healthy postmenopausal women (aged 45-65 years) participated in a randomized, diet-controlled, crossover trial. They consumed beer or alcohol-free beer (men: 4 units/day; women: 3 units/day) during 3 weeks, separated by a 1-week washout. On days 5, 10, 15, and 20 of each period, fasting blood samples were taken. RESULTS: Plasma tHcy (microM) and S-adenosyl methionine/S-adenosyl homocysteine ratio were not affected by consumption of beer or alcohol-free beer (p = 0.33 and p = 0.14, respectively). Plasma pyridoxal-5-phosphate (microg/liter) increased during consumption of beer (+11.0%), whereas it decreased during consumption of alcohol-free beer (-34.0%; p = 0.042). Changes over time of plasma vitamin B6 (microg/liter) were similar to changes in plasma pyridoxal-5-phosphate (p = 0.10). Serum vitamin B12 was higher (p < 0.001) after 3 weeks consumption of alcohol-free beer (382.8 +/- 23.7 pg/liter) as compared with beer consumption (327.5 +/- 22.2 pg/liter). Changes in serum methionine, cysteine, cystathionine, and plasma folate were not different between beer-drinking and alcohol-free beer-drinking periods. CONCLUSIONS: This study shows that moderate alcohol consumption does not affect plasma tHcy concentrations or S-adenosyl methionine/S-adenosyl homocysteine ratio. However, it does increase plasma vitamin B6 and decrease serum vitamin B12.     

Cerebral protection during percutaneous carotid intervention: wich device should be used ?

Embolic complications remain the major and unpredictable clinical event during carotid angioplasty and stenting. Cerebral protection devices could play an important role in the prevention of such emboli. Protection devices such as occlusion balloons, filters and reversed flow devices are currently undergoing clinical evaluation and appear to be promising in reducing the incidence of embolic events. This article provides an overview of the three different types of embolic protection devices.     

Targeted disruption of the IA-2beta gene causes glucose intolerance and impairs insulin secretion but does not prevent the development of diabetes in NOD mice

Insulinoma-associated protein (IA)-2beta, also known as phogrin, is an enzymatically inactive member of the transmembrane protein tyrosine phosphatase family and is located in dense-core secretory vesicles. In patients with type 1 diabetes, autoantibodies to IA-2beta appear years before the development of clinical disease. The genomic structure and function of IA-2beta, however, is not known. In the present study, we determined the genomic structure of IA-2beta and found that both human and mouse IA-2beta consist of 23 exons and span approximately 1,000 and 800 kb, respectively. With this information, we prepared a targeting construct and inactivated the mouse IA-2beta gene as demonstrated by lack of IA-2beta mRNA and protein expression. The IA-2beta(-/-) mice, in contrast to wild-type controls, showed mild glucose intolerance and impaired glucose-stimulated insulin secretion. Knockout of the IA-2beta gene in NOD mice, the most widely studied animal model for human type 1 diabetes, failed to prevent the development of cyclophosphamide-induced diabetes. We conclude that IA-2beta is involved in insulin secretion, but despite its importance as a major autoantigen in human type 1 diabetes, it is not required for the development of diabetes in NOD mice.     

In vivo PLT increments after transfusions of WBC-reduced PLT concentrates stored for up to 7 days

BACKGROUND: Bacterial screening and improvement of storage conditions of leukoreduced PLT concentrates (LR-PCs) allows extension of their storage period from 5 to 7 days. STUDY DESIGN AND METHODS: For in vitro studies, 40 LR-PCs made from five buffy coats and plasma were studied for 8 days. For in vivo studies, routinely produced LR-PCs stored for 2 to 7 days after blood collection were administered to clinically stable thrombocytopenic patients. CI1 h was calculated after 353 transfusions (67 patients), and CCI1 h, after 195 transfusions (55 patients), with pretransfusion PLT counts of not greater than 20 x 10(9) per mL. RESULTS: Storage experiments showed that the pH of LR-PCs remained greater than 6.8 for 8 days, provided that the PLT concentration was less than 1.3 x 10(9) per mL. Routinely produced LR-PCs had a volume of 282 +/- 15 mL (n = 10,193) and contained 329 x 10(9)+/- 40 x 10(9) PLTs (n = 3467). For 7-day-old LR-PCs, 76 of 78 (97%) of the transfusions resulted in a CI1 h of at least 10 and 37 of 39 (95%) in a CCI1 h of at least 7.5, which indicated levels for successfulness. Mean +/- SE values of CI1 h and CCI1 h of 7-day-old LR-PCs were 28.7 +/- 2.3 (n = 78) and 19.0 +/- 2.0 (n = 39), respectively. No significant differences were observed between 5- and 7-day-old LR-PCs transfused with respect to CI1 h and CCI1 h values. CONCLUSION: In vitro and in vivo studies showed that LR-PCs can be stored for up to 7 days with excellent clinical results, provided that they are routinely screened for bacterial contamination.