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Biomedical subjects

N S Ambrose

Publications and source records attributed to N S Ambrose.

At least 19 recordsLinked to original sources
PubMed2000

Prognostic value of magnetic resonance imaging in the management of fistula-in-ano.

PURPOSE: Magnetic resonance imaging of fistula-in-ano has been shown to predict surgical anatomy accurately and identify complex features. In addition, fistula complexity has been correlated with poor outcome after surgical intervention. We investigated whether preoperative magnetic resonance imaging could predict clinical outcome after surgery for fistulous disease better than clinical examination under anesthetic. METHODS: Seventy patients with clinically suspected fistula-in-ano underwent preoperative dynamic contrast-enhanced magnetic resonance imaging before surgical exploration. Outcome was assessed at a minimum of one year after surgical exploration and correlated in a blinded fashion with the surgical and magnetic resonance grading of the severity of the fistulous disease. RESULTS: Of 70 patients, 12 were not operated on and 6 were lost to follow-up, making 52 patients eligible for analysis. Assessment by dynamic contrast-enhanced magnetic resonance imaging more accurately predicted outcome than the findings at initial surgical exploration. Dynamic contrast-enhanced magnetic resonance imaging had a sensitivity of 81 percent, specificity of 73 percent, and positive predictive value of 75 percent; surgery had a sensitivity of 77 percent, specificity of 46 percent, and positive predictive value of 59 percent. Surgical assessment of apparent disease severity bore no relation to final outcome. Dynamic contrast-enhanced magnetic resonance imaging could accurately predict whether patients were likely to have a satisfactory or unsatisfactory outcome after surgery. CONCLUSION: Dynamic contrast-enhanced magnetic resonance imaging better predicts clinical outcome of patients with fistula-in-ano than initial surgical exploration.

Adult↗
PubMed1999

Colorectal cancer.

Explore the source record for details and available documents.

Anastomosis, Surgical↗
PubMed1999

The use, value and safety of herniography.

AIMS: To assess the safety, sensitivity and specificity of out-patient herniography when used to diagnose hernias in the presence of a normal or equivocal physical examination. MATERIALS AND METHODS: This retrospective study reviewed the symptoms, clinical findings, radiological findings, surgical findings and clinical outcome of 112 patients referred for herniography over a 5-year period. RESULTS: No significant complications were encountered. Thirty hernias were diagnosed. There was one false-positive and one false-negative examination giving herniography a sensitivity of 96.6% and a specificity of 98.4%. CONCLUSION: Herniography is a sensitive, specific, safe and reliable investigation which should be available to and used by all surgeons who perform hernia repair operations.

Adult↗
PubMed1998

Dynamic contrast-enhanced MR imaging of perianal fistulae.

We describe the normal magnetic resonance (MR) anatomy of the perianal region and relate this to the surgical anatomy of perianal fistulae. We illustrate the surgical classification of perianal fistulae and the range of complications of fistulous disease encountered in clinical practice.

Anal Canal↗
PubMed1998

Serum concentrations of soluble adhesion molecules in patients with colorectal cancer.

The concentrations of the soluble adhesion molecules E-cadherin, E-selectin, intercellular adhesion molecule-1 (ICAM-1) and vascular cell adhesion molecule-1 (VCAM-1) were investigated in 48 patients with colorectal cancer before treatment, and their relation to clinical, histological and routine laboratory parameters was examined. Data were collected on tumour stage at presentation, presence and sites of metastatic disease, tumour pathology and results of routine laboratory tests. Serum concentrations of ICAM-1 and VCAM-1 were significantly elevated in the patients with colorectal cancer in comparison with a group of healthy subjects (P < 0.00001). Levels of circulating ICAM-1 and VCAM-1 were increased both in patients with local and those with metastatic disease. Although elevated in some patients soluble E-cadherin and E-selectin concentrations were not significantly elevated compared with the control group (P = 0.71 and P = 0.052 respectively). The levels of circulating ICAM-1 were significantly correlated with those of VCAM-1 and E-selectin. A correlation was also found between the serum concentrations of E-selectin and ICAM-1 and alkaline phosphatase, total white cell count and platelet count. VCAM-1 was positively correlated with age and negatively with degree of tumour differentiation and haemoglobin concentration. The biological implications and possible clinical relevance of these findings are discussed.

Adult↗
PubMed1998

Pseudomyxoma peritonei.

BACKGROUND: Pseudomyxoma peritonei is an unusual condition in which gelatinous fluid collections are associated with mucinous implants on the peritoneal surfaces and omentum. The pathological origin and ideal treatment of the condition are subjects of debate. METHODS: An unrestricted Medline search over 1986-1997 was performed for pseudomyxoma peritonei. RESULTS AND CONCLUSIONS: There is increasing evidence that pseudomyxoma peritonei is a neoplastic condition which usually arises from a primary adenoma or adenocarcinoma of the appendix. Reported series include a spectrum of pathological lesions, from entirely benign ruptured mucocele to advanced carcinoma. This, and the rarity of the condition, limit the conclusions that can be drawn regarding its treatment and prognosis. Most authorities agree that a thorough surgical debulking should be made. In most cases this will be a difficult and time-consuming undertaking, possibly requiring cooperation between two or more specialists and consideration of delivering intraperitoneal adjuvant therapy during or immediately after surgery. Treatment therefore requires a planned approach with accurate preoperative assessment of the diagnosis and the extent of the condition. There is some largely anecdotal evidence in favour of intraperitoneal chemotherapy and radioisotope treatment. Ultraradical surgery, with heated intraoperative and further postoperative chemotherapy, is strongly advocated by one group but remains contentious. The majority of patients will eventually suffer recurrence. The 5-year survival rate ranges from 53 to 75 per cent, but outcomes vary widely between relatively benign and malignant subgroups.

Combined Modality Therapy↗
PubMed1998

A prospective randomised controlled study of the use of ranitidine in patients with gastric cancer. Yorkshire GI Tumour Group.

BACKGROUND: Does the use of the histamine H2 receptor antagonist ranitidine improve the outcome of patients with gastric cancer? PATIENTS: A total of 222 patients with gastric cancer who had received radical or palliative resection or who were deemed inoperable at presentation. SETTING: Hospitals within Yorkshire, the participating clinicians being members of the Yorkshire GI Tumour Group. METHODS: A multicentre prospective randomised double blind trial comparing ranitidine 150 mg twice daily with placebo twice daily was undertaken. The principal outcome measures were survival and survival excluding those who died within 30 days of operation. RESULTS: The median survival (95% confidence intervals) was 331 (232 to 393) days for patients in the ranitidine group compared with 187 (143 to 269) for those in the placebo group. The difference in survival was not statistically significant (p = 0.225). When patients who died within 30 days of operation were excluded (21 in the placebo group, 15 in the ranitidine group), the difference in survival remained not significant (p = 0.358). No subgroup could be identified who significantly benefited from treatment, but for patients with stage VIa cancer the median survival was 134 days with placebo compared with 313 days with ranitidine (p = 0.073). CONCLUSION: This study does not show significant benefit from the use of ranitidine for gastric cancer but further larger studies may be indicated.

Adult↗
PubMed1998

Outcome after surgery for perianal fistula: predictive value of MR imaging.

OBJECTIVE: The purpose of this study was to determine if MR findings are predictive of long-term outcome in a cohort of patients whose initial surgery was performed without access to the findings of MR imaging. SUBJECTS AND METHODS: Forty patients with surgically proven perianal fistulas underwent preoperative dynamic contrast-enhanced MR imaging. The MR and surgical findings were independently recorded on an identical anatomic form. Three patients were subsequently lost to follow-up. The outcome for the remaining 37 patients was determined from surgical review, case notes, and questionnaires. Minimum follow-up period was 14 months (range, 14-39 months). Outcome was determined by one observer who was unaware of the initial MR grading and had not been present during surgery. Outcome was considered unsatisfactory if further surgery was required. RESULTS: MR imaging was better than surgical exploration in predicting outcome (for MR imaging: positive predictive value, 73%; negative predictive value, 87%; sensitivity, 89%; and specificity, 68%; for surgical exploration: positive predictive value, 57%; negative predictive value, 64%; sensitivity, 73%; and specificity, 47%). MR classification of fistulas was significantly associated with outcome (p = .0004), and surgical classification was not significantly associated with outcome (p = .22, chi-square test). Also MR grades differed significantly for patients with satisfactory and unsatisfactory outcomes (p < .001, Mann-Whitney U test). CONCLUSION: MR imaging is valuable in the management of patients with perianal fistulas. MR imaging accurately reveals surgical anatomy and can be used to make better predictions regarding patient outcome than surgical findings.

Adult↗
PubMed1997

Circulating soluble adhesion molecules E-cadherin, E-selectin, intercellular adhesion molecule-1 (ICAM-1) and vascular cell adhesion molecule-1 (VCAM-1) in patients with gastric cancer.

The concentrations of the soluble adhesion molecules E-cadherin, E-selectin, intercellular adhesion molecule-1 (ICAM-1) and vascular cell adhesion molecule-1 (VCAM-1) were investigated in 45 patients with gastric cancer before treatment and their correlation with clinical, histological and routine laboratory parameters was examined. Data were collected on tumour stage at presentation, presence and sites of metastatic disease, tumour pathology, survival and results of routine laboratory tests. Serum concentrations of ICAM-1 and VCAM-1 were significantly elevated in the patients with gastric cancer in comparison with the group of healthy subjects (P < 0.00001 and P < 0.0001 respectively). Increased serum concentrations of VCAM-1 were associated with locally advanced and metastatic disease whereas ICAM-1 was significantly elevated both in local and in advanced/metastatic disease. Soluble E-cadherin and E-selectin concentrations did not show any significant elevation in gastric cancer patients. Concentrations of soluble adhesion molecules showed significant correlation with each other (except E-selectin and VCAM-1) and with alkaline phosphatase. Soluble ICAM-1 and VCAM-1 were significantly associated with an elevated total white cell count. Patients with elevated VCAM-1 had significantly poorer survival in comparison with patients with normal serum levels (P = 0.0361).

Adult↗
PubMed1996

Prospective evaluation of dynamic contrast enhanced magnetic resonance imaging in the evaluation of fistula in ano.

Forty-two patients with a suspected diagnosis of fistula in ano underwent prospective comparison of digital rectal examination, dynamic contrast enhanced magnetic resonance imaging (DCEMRI) and surgical exploration. There were five discordancies: DCEMRI showed an ischiorectal abscess and track with no enteric connection in one patients who at operation was found to have a well epithelialized primary fistula. Four patients with fistulas on DCEMRI had no enteric opening found at surgery and were treated as having sinuses. Long-term follow-up has shown failure to heal in all patients and further surgery confirmed missed fistula. Compared with final outcome measures DCEMRI had a sensitivity of 97 per cent and specificity of 100 per cent in the detection of fistula. DCEMRI also identified more secondary tracks and was more accurate at identifying complex fistulas than either digital rectal examination alone or surgical exploration.

Adult↗
PubMed1996

Dynamic contrast-enhanced MR imaging of perianal fistulas.

OBJECTIVE: The objective of this study was to prospectively compare dynamic contrast-enhanced MR imaging with MR sequences previously described for assessing perianal fistulas in order to determine the best MR protocol for their evaluation. SUBJECTS AND METHODS: MR examinations of 42 consecutive patients with clinically suspected perianal fistulas were independently evaluated by two experienced observers blinded to the findings of digital rectal examination. The observers' evaluations occurred before definitive surgical exploration. All patients had body-coil MR imaging examinations, including the following sequences that were ranked for anatomic and pathologic information: spin-echo T1-weighted, short inversion time inversion recovery, and dynamic contrast-enhanced MR imaging in the coronal plane; and spin-echo T2-weighted imaging in the axial plane. Surgical findings were accepted as the gold standard and were recorded independently by the surgeon, who was unaware of the findings of the MR assessment. MR findings were subsequently correlated with digital rectal examination before surgery and with clinical follow-up. RESULTS: MR imaging correctly allowed our blinded observers to predict the surgical anatomy of perianal disease in 37 of the 42 patients (accuracy, 88%). For detection of the presence and site of an enteric fistulous entry, MR imaging had a sensitivity of 97%, a specificity of 67%, a positive predictive value of 88%, and a negative predictive value of 89%. On MR imaging examination, eight patients had no fistula, 12 had simple intersphincteric fistulas, and 22 had complex fistulas. MR imaging revealed all 14 perianal abscesses and fluid collections found at surgery. Digital rectal examination before surgery failed to reveal abscesses or important secondary tracks in eight of the 22 complex fistulas. For anatomic and pathologic depiction of fistulas, dynamic contrast-enhanced MR imaging ranked as the best sequence for 22 of 34 fistulas. The short inversion time inversion recovery sequence, which was unable to distinguish small abscesses from perianal inflammation and showed spurious high signal in old fibrotic tracks, led our observers to misdiagnose five cases. In four patients for which initial surgery did not confirm enteric entry sites that our observers had predicted by MR imaging, follow-up has confirmed the observers' diagnoses. The observers' evaluations of the MR examinations agreed in 37 (88%) of the 42 cases. CONCLUSION: MR imaging is more accurate than digital rectal examination before surgery in detecting complex features of perianal fistulas. MR imaging is noninvasive, is highly accurate, and has low interobserver variability. With MR imaging, observers may better predict outcome than with initial surgical exploration. MR assessment that includes dynamic contrast-enhanced MR imaging and axial T2-weighted sequences (examination time, 20 min) provides the anatomic and pathologic information required to guide surgical management.

Adult↗
PubMed1995

Early gastric cancer in a patient with Menetrier's disease, lymphocytic gastritis and Helicobacter pylori.

OBJECTIVE: To describe a patient with early gastric cancer, Menetrier's disease, lymphocytic gastritis and Helicobacter pylori infection. DESIGN: A single patient case report. PATIENT: A 73-year-old man presenting with lower limb deep venous thrombosis was found to have a gastric adenocarcinoma on upper gastrointestinal endoscopy. He subsequently had a total gastrectomy. RESULTS: Histological examination of the resected stomach showed an early gastric cancer and changes typical of Menetrier's disease, lymphocytic gastritis and Helicobacter-associated chronic gastritis. CONCLUSION: This case suggests a link between gastric adenocarcinoma, Menetrier's disease and lymphocytic gastritis. The presence of H. pylori is postulated as a possible aetiology.

Adenocarcinoma↗
PubMed1993

Peri-operative modulation of cellular immunity in patients with colorectal cancer.

The peri-operative cellular immune response is depressed in patients with gastrointestinal cancer, a factor which may facilitate malignant dissemination. We have investigated the effects of peri-operative rIL-2 and a combination of rIL-2 and interferon-alpha (IFN-alpha) on both peripheral blood lymphocyte function and number in patients undergoing surgical resection for colorectal cancer. Fifty-two patients were randomly allocated to either control, rIL-2 or rIL-2 with IFN-alpha treatment arms. In vitro studies were performed pre-operatively and on post-operative days 1, 4, 7 and 10. Natural killer (NK) and lymphokine-activated killer (LAK) cell function were profoundly depressed in control patients (P < 0.001; P < 0.01), an effect abrogated in both treatment groups; indeed NK function was augmented in the rIL-2 and IFN-alpha group on the first post-operative day in association with an increase in the percentage of cells expressing CD16 and CD56 (P < 0.01). Flow cytometric analysis of lymphocyte subsets in the control group was unremarkable, except for an early post-operative fall in numbers of lymphocytes. Treatment with either rIL-2 or rIL-2 and IFN-alpha produced an initial profound reduction in T lymphocyte numbers, followed by a 'rebound' lymphocytosis of activated CD3+ T cells, as demonstrated by a significant increase in co-expression of CD25, CD38 and CD45RO. No significant differences were observed between either of the treatment groups. Adjuvant immunotherapy affects peri-operative anti-tumour immune responses, and this may influence long term outcome in patients undergoing surgery for gastrointestinal cancer.

Colorectal Neoplasms↗
PubMed1990

Quantitative appraisal of Picolax (sodium picosulfate/magnesium citrate) in the preparation of the large bowel for elective surgery.

The authors have investigated the metabolic sequelae Picolax bowel preparation in a group receiving their preparation either 24 hours (n = 17) or 48 hours (n = 18) before elective colonic resection. No significant changes in any metabolic parameter were found in the 24-hour group. In the 48-hour group, there was a significant decrease in serum sodium (P less than 0.005), serum chloride (P less than 0.005), pH (P less than 0.005), HCO3 (P less than 0.005), and base excess (P less than 0.005). Only 16 of 35 cases (46 percent) had an acceptable bowel preparation: 11 of 17 (65 percent) in the 24-hour group and 5 of 18 (28 percent) in the 48-hour group. Marker studies did not correlate with the quality of bowel preparation. The risk of potentially explosive intraluminal gas was increased if the bowel preparation was poor: 12 of 19 patients (63 percent) with a poor bowel preparation compared with 3 of 16 patients (19 percent) of those with an acceptable preparation (P less than 0.005). Picolax is a poor mechanical bowel preparation and is associated with unacceptable physiologic disturbance if given two days before surgery.

Acid-Base Equilibrium↗
PubMed1990

Selective salvage surgery in gastrointestinal and gynaecological cancer.

The role of reoperation with intent to excise locally recurrent disease has been evaluated in a selected group of 64 patients originally treated for primary gastrointestinal or gynaecological cancer. In 16 (25%), surgery was successful in eradicating all known sites of disease and was associated with a median survival of 23 months. Patients most suitable for reoperation were those with non-specific gastrointestinal symptoms or asymptomatic local disease. Nevertheless, those with specific symptoms may have treatable local disease or even benign conditions, and thus all with suspected local recurrence should be evaluated with a view to salvage surgery.

Colorectal Neoplasms↗
PubMed1989

The fecal microflora in pruritus ani.

Pruritus ani is a common condition in which there is a tendency for liquids to leak from the anal canal, resulting in perianal soiling. In order to ascertain if an abnormal fecal flora contributes to the irritant effects of fecal material, qualitative and quantitative measurement of the fecal microflora was performed in 20 patients with pruritus ani and 20 matched controls. No differences were found between the two groups. This study has failed to provide evidence for a microbiologic basis for pruritus ani.

Adult↗