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Biomedical subjects

D C Winter

Publications and source records attributed to D C Winter.

At least 19 recordsLinked to original sources
PubMed2007

Local involvement of the urinary bladder in primary colorectal cancer: outcome with en bloc resection.

BACKGROUND: Colorectal cancers that adhere to the urinary bladder require en bloc partial or total cystectomy to achieve negative tumor margins. METHODS: This prospective study evaluated the outcome of combined bladder resection for carcinoma of the colon or rectum at a unit specializing in gastrointestinal cancer. RESULTS: Patients (n = 63) with colorectal tumors adherent to the bladder at operation and without distal metastases were followed. Fifty-eight patients (92%) had tumors of the sigmoid colon or upper rectum. Operative morbidity and mortality rates were 18% and 1.5%, respectively. Histological staging demonstrated bladder adherence in 46% (29/63) and invasion in 54% (34/63). Overall disease-specific survival was 54%, with a mean follow-up of 7.6 (range 5-12) years. Five-year survival for margin negative patients was 72% (26/36) and 27% (4/15) for node negative and positive tumors, respectively. The bladder was closed primarily in 48 patients and reconstructed by enterocystoplasty in five, with ten patients requiring urinary diversion. CONCLUSIONS: En bloc bladder resection for adherent or invading tumors of the colon and rectum achieves good local control, but an infiltrative extravesical margin denotes poor prognosis. The potential for cure in completely excised node negative tumors is good. Bladder reconstruction is achievable in most patients.

Adult↗
PubMed2006

Local involvement of the urinary bladder in primary colorectal cancer: outcome with en-bloc resection.

BACKGROUND: Colorectal cancers that adhere to the urinary bladder require en-bloc partial or total cystectomy to achieve negative tumor margins. METHODS: This prospective study evaluated the outcome of combined bladder resection for carcinoma of the colon or rectum at a unit specializing in gastrointestinal cancer. RESULTS: Patients (n = 63) with colorectal tumors adherent to the bladder at operation and without distal metastases were followed. Fifty-eight patients (92%) had tumors of the sigmoid colon or upper rectum. Operative morbidity and mortality rates were 18% and 1.5%, respectively. Histological staging demonstrated bladder adherence in 46% (29/63) and invasion in 54% (34/63). Overall disease-specific survival was 54% with a mean follow-up of 7.6 years (range 5-12). Five-year survival for margin-negative patients was 72% (26/36) and 27% (4/15) for node-negative and -positive tumors, respectively. The bladder was closed primarily in 48 patients and reconstructed by enterocystoplasty in 5, with 10 patients requiring urinary diversion. CONCLUSIONS: En-bloc bladder resection for adherent or invading tumors of the colon and rectum achieves good local control, but an infiltrative extravesical margin denotes poor prognosis. The potential for cure in completely excised node-negative tumors is good. Bladder reconstruction is achievable in most patients.

Adult↗
PubMed2006

Thrombomodulin expression in colorectal carcinoma is protective and correlates with survival.

Thrombomodulin (TM) is an endothelial receptor that exhibits anticoagulant, antifibrinolytic and anti-inflammatory activity by inhibiting thrombin and cellular adhesion. In this study, the expression and significance of TM was examined in primary colorectal cancer and its prognostic implications explored. TM immunostaining was performed on formalin-fixed, paraffin-embedded tissue sections, from primary lesions of 200 patients with colorectal carcinoma. Institutional Ethical approval was granted and clinical data retrieved from patients' records. All normal colonic tissue expressed TM on endothelial cells. TM tumour cell expression was demonstrated in 53 (26.5%) cases and 147 (73.5%) showed no neoplastic cell staining. On univariate and multivariate analysis TM expression on tumour cells correlated significantly with tumour stage, differentiation, Jass score and 5 year survival. TM expression decreases as overall stage and tumour size increase (P=0.03). In all, 91% TM positive tumours were well differentiated and 85% of TM negative tumours were poorly differentiated (P<0.01). Five year survival rates of patients with positive and negative TM expression were 71 and 41%, respectively. Survival rate was poorer in those patients who were TM negative compared with those who were positive (P<0.01). A total of 101 (50.5%) of the cases were node negative. In this group, 5 year survival rates of patients with positive and negative TM expression were 87.5 and 37.8%, respectively, demonstrating a poorer survival rate for those who are node negative and TM negative at the time of surgery (P<0.001). This study demonstrates that loss of TM is a key indicator in tumour biology and prognosis.

Adenocarcinoma↗
PubMed2006

Perineal hernia after proctectomy: prevalence, risks, and management.

PURPOSE: Perineal hernias are infrequent complications of abdominoperineal operations with estimated historic prevalences (from the era where the perineal wound was left open) ranging from 0.6 to 7 percent. The purpose of this study was to identify the modern prevalence of postoperative perineal hernias, factors that may contribute to their development, and examine the methods of repair. METHODS: The Mayo Clinic patient database (1990-2000) was interrogated for the following data identifiers: incisional hernia, perineal hernia, abdominoperineal resection, proctocolectomy, and partial or total pelvic exenteration. All surviving patients were followed up to December 2005. The retrieved patient data was retrospectively analyzed. RESULTS: Of a total of 3,761 patients who underwent abdominoperineal resection (including nonrestorative proctocolectomy and pelvic exenteration) during the study period, 8 developed a perineal hernia (5 females). The median age at hernia presentation was 76 (range, 69-84) years, representing a median interval of 22 (range, 1-60) months from the original operation. All were smokers (> or =15 pack years) and five had received chemoradiotherapy for their original diagnosis. The commonest prevalence was found in patients who had undergone abdominoperineal resection (5/1,266) or pelvic exenteration (2/1,334). Only 1 of 1,161 patients developed a perineal hernia after proctocolectomy despite most being on perioperative immunosuppression for inflammatory bowel disease. Abdominal exploration and repair was performed in four patients whereas four underwent perineal repair (2 of each with mesh). None have recurred with a median follow-up of 36 (range, 6-60) months. CONCLUSIONS: Perineal hernias are rare complications of abdominoperineal surgery with a more common prevalence after cancer operations. Smoking and chemoradiotherapy, but not corticosteroid immunosuppression, may be factors. The abdominal approach has advantages over the perineal approach, but both are suitable with good medium-term results.

Abdomen↗
PubMed2005

Thrombomodulin: tumour biology and prognostic implications.

BACKGROUND: Thrombomodulin (TM) is an endothelial receptor that exerts anti-coagulant, anti-fibrinolytic, and anti-inflammatory activity by inhibiting thrombin and cellular adhesion. There is growing evidence that TM plays a role in tumour behaviour. METHODS: The electronic literature (1966-2004) was reviewed with a specific focus on tumour biology. RESULTS: TM is expressed on both the endothelium and tumour cells in several cancers. Loss of expression denotes a more malignant profile with poorer prognosis. Loss of TM is mediated by hypoxia, endotoxin, and various cytokines, while up-regulation can be achieved by pharmacological manipulation (e.g. pentoxyfylline and statins). CONCLUSION: Originally described as an endothelial anticoagulant, TM plays a key role in tumour biology and prognostics, and provides a potential therapeutic target in impeding cancer spread.

Animals↗
PubMed2004

Perioperative topical nitrate and sphincter function in patients undergoing transanal stapled anastomosis: a randomized, placebo-controlled, double-blinded trial.

PURPOSE: The use of transanal stapling devices may impair continence because of digital dilatation and/or instrumentation. This study assessed the effect of pharmacological dilatation of the sphincter prior to stapler insertion. METHODS: A randomized, placebo-controlled, double-blinded study of 60 patients undergoing transanal stapled anastomosis was undertaken. Consenting patients were randomly assigned to receive a single intraoperative dose of topical 0.2 percent nitroglycerin (glyceryl trinitrate) ointment or nitroglycerin-free placebo. All patients were assessed preoperatively and postoperatively by clinical methods (Wexner incontinence scores and examination), anorectal manometry by a station pull-through technique, and endoanal ultrasonography. RESULTS: Intraoperative mean (+/-SEM) resting pressures (mmHg) were significantly reduced by nitroglycerin compared with prenitroglycerin levels (9.9 +/- 0.9 vs. 50.5 +/- 2.7; P = 0.002) or controls (56.0 +/- 3.2; P = 0.001). Twenty-one of the 28 controls (75 percent) but only 4 of the 32 patients in the nitroglycerin group (12.5 percent) required digital dilatation to insert the stapling instrument ( P = 0.003). Squeeze pressures were unaltered by the intervention but mean resting pressures were higher in the nitroglycerin group postoperatively (52.9 +/- 3.2 - 31.6 +/- 1.3 = 21.3 mmHg; 95 percent confidence interval, 14-27). Incontinence scores were lower in the nitroglycerin group at the 3-month (1.1 +/- 0.2 vs. 4.6 +/- 0.3; P = 0.003) and 12-month (0.9 +/- 0.1 vs. 4.4 +/- 0.3; P = 0.002) clinic visits. CONCLUSION: Preoperative nitroglycerin dilatation protects sphincter function in patients undergoing transanal stapled anastomoses.

Administration, Topical↗
PubMed2004

Giant mixed type retroperitoneal liposarcoma.

Retroperitoneal liposarcoma is a rare tumour that often presents late due to its indolent nature and large potential growing space. Total resection is the aim, including adjacent organs if necessary. Recurrence is common, and 5-year disease-free interval is not regarded as a cure. We present a case of a 57 year old man who had a 17 kg liposarcoma surgically excised.

Humans↗
PubMed2003

Sentinel lymph node mapping in colorectal cancer.

BACKGROUND: Ultrastaging, by serial sectioning combined with immunohistochemical techniques, improves detection of lymph node micrometastases. Sentinel lymph node mapping and retrieval provides a representative node(s) to facilitate ultrastaging. The impact on staging of carcinoma of the colon and rectum in all series emphasizes the importance of this technique in cancer management. Now the challenge is to determine the biological relevance and prognostic implications. METHODS: The electronic literature (1966 to present) on sentinel node mapping in carcinoma of the colon and rectum was reviewed. Further references were obtained by cross-referencing from key articles. RESULTS: Lymphatic mapping appears to be readily applicable to colorectal cancer and identifies those lymph nodes most likely to harbour metastases. Sentinel node mapping carries a false-negative rate of approximately 10 per cent in larger studies, but will also potentially upstage a proportion of patients from node negative to node positive following the detection of micrometastases. The prognostic implication of these micrometastases requires further evaluation. CONCLUSION: Further follow-up to assess the prognostic significance of micrometastases in colorectal cancer is required before the staging benefits of sentinel node mapping can have therapeutic implications.

Colorectal Neoplasms↗
PubMed2003

Quality-of-life assessment of patients after ileal pouch-anal anastomosis for slow-transit constipation with rectal inertia.

PURPOSE: Severe idiopathic constipation with rectal inertia represents a challenging medical problem that, in extremis, might warrant surgery. We studied a group of patients who have undergone proctocolectomy and ileal pouch-anal anastomosis for this problem. The purpose was to assess the functional success of this procedure and its impact on the social function of the patients. METHODS: Patients with functional, intractable constipation have one motion or less per week and are laxative-dependent. The indication for surgery was based on failure of long-term medical therapy. The selection criteria were normal colonoscopy, normal anal manometry and pudendal nerve latency test, and abnormal transit study and abnormal video proctography. The functional outcome after surgery was assessed by anal manometry and stool frequency. Quality of life was analyzed using the Rand health survey 1.0 consisting of a comprehensive questionnaire used preoperatively and postoperatively with emphasis on physical function, role limitation because of functional/emotional problems, social function, pain, and general health. RESULTS: Fifteen patients (14 females) underwent ileal pouch-anal anastomosis over a seven-year period (1993-1999). The mean age was 41 (range, 25-47) years. All had a temporary defunctioning loop ileostomy fashioned, and there were no anastomotic leaks. Two patients required pouch excision within 18 months because of intractable pelvic pain. The mean stool frequency was eight (range, 3-12) per day at the first follow-up. At the second follow-up, this had improved to five (range, 2-6) per day. The mean resting and squeeze anal pressures preoperatively were 82 cm H2O and 104 mmHg, respectively, and were unchanged after surgery. Significant improvement in lifestyle scores were recorded in the categories of physical function, social function, and pain at the first follow-up and in all categories at the second follow-up (P < 0.05). CONCLUSION: Restorative proctocolectomy is an option in selected patients and leads to progressive improvement in quality of life.

Adult↗
PubMed2002

Soluble interleukin 6 receptor (sIL-6R) mediates colonic tumor cell adherence to the vascular endothelium: a mechanism for metastatic initiation?

The mechanisms by which surgery increases metastatic proliferation remain poorly characterized, although endotoxin and immunocytes play a role. Recent evidence suggests that endothelial adherence of tumor cells may be important in the formation of metastases. Soluble receptors of interleukin-6 (sIL-6R) shed by activated neutrophils exert IL-6 effects on endothelial cells, which are unresponsive under normal circumstances. This study examined the hypothesis that sIL-6R released by surgical stress increases tumor cell adherence to the endothelium. Neutrophils (PMN) were stimulated with lipopolysaccharide, C-reactive protein (CRP), and tumor necrosis factor-alpha. Soluble IL-6R release was measured by enzyme-linked immunosorbent assay. Colonic tumor cells transfected with green fluorescent protein and endothelial cells were exposed to sIL-6R, and tumor cell adherence and transmigration were measured by fluorescence microscopy. Basal release of sIL-6R from PMN was 44.7 +/- 8.2 pg/ml at 60 min. This was significantly increased by endotoxin and CRP (131 +/- 16.8 and 84.1 +/- 5.3, respectively; both P < 0.05). However, tumor necrosis factor-alpha did not significantly alter sIL-6R release. Endothelial and tumor cell exposure to sIL-6R increased tumor cell adherence by 71.3% within 2 h but did not significantly increase transmigration, even at 6 h. Mediators of surgical stress induce neutrophil release of a soluble receptor for IL-6 that enhances colon cancer cell endothelial adherence. Since adherence to the endothelium is now considered to be a key event in metastatic genesis, these findings have important implications for colon cancer treatment strategies.

Cell Adhesion↗
PubMed2002

Inosine modulates gut barrier dysfunction and end organ damage in a model of ischemia-reperfusion injury.

INTRODUCTION: Gut barrier failure is an important source of morbidity in critically ill patients, and patients undergoing aortic cross-clamp. Inosine, an endogenous purine nucleoside without known side effects, formed from the breakdown of adenosine by adenosine deaminase, has been shown to modify the effects of hypoxia on various tissues, including the heart and the brain. MATERIALS AND METHODS: This study examined the effect of inosine on ischemia-reperfusion-induced gut barrier dysfunction and on the associated lung injury. Twenty-four male Sprague-Dawley rats were divided into three groups. Eight were subjected to 60 min of superior mesenteric artery occlusion followed by 4 h of reperfusion. Eight had 100 mg/kg inosine prior to ischemia-reperfusion and 8 had sham laparotomy with encircling but not occlusion of the superior mesenteric artery. RESULTS: Rats treated with inosine had significantly less gut barrier dysfunction. Rats subjected to SMAO sustained a substantial lung injury and this was attenuated by inosine treatment. Serum cytokine levels were also significantly lower. CONCLUSIONS: We conclude that inosine has a beneficial effect in modulating both gut barrier dysfunction and distant organ injury in response to gut ischemia-reperfusion.

Animals↗
PubMed2002

Quality of life after ileal pouch-anal anastomosis: an evaluation of diet and other factors using the Cleveland Global Quality of Life instrument.

PURPOSE: Although functional results after ileal pouch-anal anastomosis are excellent, imperfections of function do occur. In this setting, quality-of-life assessment is an invaluable tool in determining overall therapeutic efficacy. We evaluated the impact of dietary restrictions, preoperative diagnosis (ulcerative colitis vs. familial adenomatous polyposis), and pregnancy (after pouch insertion) on quality of life. METHODS: After ethical approval, 64 patients were reviewed (mean age, 31 (range, 15-54) years). Long-term quality of life in patients after ileal pouch-anal anastomosis was assessed using the Cleveland Global Quality of Life instrument or Fazio score. The Cleveland Global Quality of Life score is a novel quality-of-life instrument specifically designed for patients with ileal pouches. Stool frequency and continence were recorded to establish the functional status of this group. RESULTS: Sixty-one patients (95.3 percent) complained of some form of dietary restriction and adopted a fixed dietary regimen. All such patients felt that a breach of this regimen would impinge significantly on their quality of life. Late eating and alcohol were associated with diarrhea, whereas smoking was not. Constipation was infrequently reported. The mean Cleveland Global Quality of Life score of patients with ulcerative colitis (0.81 +/- 0.13) was greater than that of patients with ulcerative colitis and a background of pouchitis (0.78 +/- 0.16; P = 0.042). Whereas postoperative stool frequency in patients with familial adenomatous polyposis was always higher than the preoperative level (4 vs. 2 movements per day; P = 0.04), the Cleveland Global Quality of Life score of this group was lower than that of ulcerative colitis patients (0.77 vs. 0.81; P = 0.047). The Cleveland Global Quality of Life score of females who had had pregnancies after pouch formation was 0.70, significantly lower (P = 0.039) than that of ulcerative colitis patients, although pouch function was similar to the general group (7 vs. 6 daily bowel movements with full continence in all parous patients). CONCLUSIONS: Most patients suffered dietary restrictions, forcing them to adopt a fixed dietary regimen. Breach of this regimen would impact on their quality of life. Hence composition of diet and timing of intake are important determinants of quality of life after ileal pouch formation. Patients with familial adenomatous polyposis and those with a history of pouchitis had poorer Cleveland Global Quality of Life scores than ulcerative colitis patients without a background of pouchitis. This indicates that they also had poorer quality of life. Parous patients had the lowest Cleveland Global Quality of Life scores, indicating the poorest quality of life. These differences did not correlate with poorer pouch function, highlighting the influence of non-pouch-related factors in quality of life after ileal pouch formation.

Adenomatous Polyposis Coli↗
PubMed2001

Structure of Arp2/3 complex in its activated state and in actin filament branch junctions.

The seven-subunit Arp2/3 complex choreographs the formation of branched actin networks at the leading edge of migrating cells. When activated by Wiskott-Aldrich Syndrome protein (WASp), the Arp2/3 complex initiates actin filament branches from the sides of existing filaments. Electron cryomicroscopy and three-dimensional reconstruction of Acanthamoeba castellanii and Saccharomyces cerevisiae Arp2/3 complexes bound to the WASp carboxy-terminal domain reveal asymmetric, oblate ellipsoids. Image analysis of actin branches indicates that the complex binds the side of the mother filament, and Arp2 and Arp3 (for actin-related protein) are the first two subunits of the daughter filament. Comparison to the actin-free, WASp-activated complexes suggests that branch initiation involves large-scale structural rearrangements within Arp2/3.

Acanthamoeba↗
PubMed2001

Tumor cell adhesion to endothelial cells is increased by endotoxin via an upregulation of beta-1 integrin expression.

BACKGROUND: Recent studies have demonstrated that metastatic disease develops from tumor cells that adhere to endothelial cells and proliferate intravascularly. The beta-1 integrin family and its ligand laminin have been shown to be important in tumor-to-endothelial cell adhesion. Lipopolysaccharide (LPS) has been implicated in the increased metastatic tumor growth that is seen postoperatively. We postulated that LPS increases tumor cell expression of beta-1 integrins and that this leads to increased adhesion. METHODS: The human metastatic colon cancer cell line LS174T was labeled with an enhanced green fluorescent protein (eGFP) using retroviral transfection. Cell cultures were treated with LPS for 1, 2, and 4 h (n = 6 each) and were subsequently cocultured for 30 or 120 min with confluent human umbilical vein endothelial cells (HUVECs), to allow adherence. Adherent tumor cells were counted using fluorescence microscopy. These experiments were carried out in the presence or absence of a functional blocking beta-1 integrin monoclonal antibody (4B4). Expression of beta-1 integrin and laminin on tumor and HUVECs was assessed using flow cytometric analysis. Tumor cell NF-kappaB activation after incubation with LPS was measured. RESULTS: Tumor cell and HUVEC beta-1 integrin expression and HUVEC expression of laminin were significantly (P < 0.05) enhanced after incubation with LPS. Tumor cell adhesion to HUVECs was significantly increased. Addition of the beta-1 integrin blocking antibody reduced tumor cell adhesion to control levels. LPS increased tumor cell NF-kappaB activation. CONCLUSIONS: Exposure to LPS increases tumor cell adhesion to the endothelium through a beta-1 integrin-mediated pathway that is NF-kappaB dependent. This may provide a target for immunotherapy directed at reducing postoperative metastatic tumor growth.

Cell Adhesion↗
PubMed2001

Inosine attenuates tourniquet-induced skeletal muscle reperfusion injury.

BACKGROUND: Adenosine attenuates skeletal muscle reperfusion injury, but its short half-life in vivo limits potential therapeutic benefits. The aim of this study was to ascertain whether inosine, a stable adenosine metabolite, modulates skeletal muscle reperfusion injury. MATERIALS AND METHODS: C57BL/6 mice were randomized (8-10 per group) to six groups: time controls; inosine (100 mg/kg) before anesthesia; 2 h of bilateral tourniquet hindlimb ischemia; I/R (2 h of bilateral tourniquet hindlimb ischemia, 3 h of reperfusion); inosine (100 mg/kg) before I/R; drug vehicle before I/R. Serum tumor necrosis factor (TNF)-alpha and macrophage inflammatory protein (MIP)-2 were measured before ischemia and at the end of reperfusion. Tissue edema was determined by wet/dry weight ratios. Tissue leucosequestration was assessed by the myeloperoxidase (MPO) content. RESULTS: At the end of reperfusion, inosine pretreatment resulted in lower MPO levels in muscle (P = 0.02) and lung (P = 0.0002) than saline pretreatment. Similarly, muscle (P = 0.04) and lung (P = 0.02) wet/dry ratios were significantly reduced with inosine but not with saline pretreatment. At the end of reperfusion, serum proinflammatory cytokine levels (TNF-alpha and MIP-2) were significantly reduced (P < 0.05) compared to preischemia levels following inosine pretreatment but not saline pretreatment. Ischemia alone did not alter any of the parameters assessed. CONCLUSIONS: These findings demonstrate that pretreatment with inosine attenuates the local and systemic proinflammatory responses associated with skeletal muscle reperfusion injury.

Animals↗