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A D Turnbull

Publications and source records attributed to A D Turnbull.

At least 19 recordsLinked to original sources
PubMed2002

Sustained stabilization of the resistive-wall mode by plasma rotation in the DIII-D tokamak.

Values of the normalized plasma pressure up to twice the free-boundary stability limit predicted by ideal magnetohydrodynamic (MHD) theory have been sustained in the DIII-D tokamak. Long-wavelength modes are stabilized by the resistive wall and rapid plasma toroidal rotation. High rotation speed is maintained by minimization of nonaxisymmetric magnetic fields, overcoming a long-standing impediment [E. J. Strait, Phys. Rev. Lett. 74, 2483 (1995)]]. The ideal-MHD pressure limit calculated with an ideal wall is observed as the operational limit to the normalized plasma pressure.

Journal Article↗
PubMed1999

Hepatic arterial infusion of chemotherapy after resection of hepatic metastases from colorectal cancer.

BACKGROUND: Two years after undergoing resection of liver metastases from colorectal cancer, about 65 percent of patients are alive and 25 percent are free of detectable disease. We tried to improve these outcomes by treating patients with hepatic arterial infusion of floxuridine plus systemic fluorouracil after liver resection. METHODS: We randomly assigned 156 patients at the time of resection of hepatic metastases from colorectal cancer to receive six cycles of hepatic arterial infusion with floxuridine and dexamethasone plus intravenous fluorouracil, with or without leucovorin, or six weeks of similar systemic therapy alone. Patients were stratified according to previous treatment and the number of liver metastases identified at operation. The study end points were overall survival, survival without recurrence of hepatic metastases, and survival without any metastases at two years. RESULTS: The actuarial rate of overall survival at two years was 86 percent in the group treated with local plus systemic chemotherapy and 72 percent in the group given systemic therapy alone (P=0.03). The median survival was 72.2 months in the combined-therapy group and 59.3 months in the monotherapy group, with a median follow-up of 62.7 months. After two years, the rates of survival free of hepatic recurrence were 90 percent in the monotherapy group and 60 percent in the monotherapy group (P<0.001), and the respective rates of progression-free survival were 57 percent and 42 percent (P=0.07). At two years, the risk ratio for death was 2.34 among patients treated with systemic therapy alone, as compared with patients who received combined therapy (95 percent confidence interval, 1.10 to 4.98; P=0.027), after adjustment for important variables. The rates of adverse effects of at least moderate severity were similar in the two groups, except for a higher frequency of diarrhea and hepatic effects in the combined-therapy group. CONCLUSIONS: For patients who undergo resection of liver metastases from colorectal cancer, postoperative treatment with a combination of hepatic arterial infusion of floxuridine and intravenous fluorouracil improves the outcome at two years.

Adenocarcinoma↗
PubMed1998

Metastatic breast cancer masquerading as gastrointestinal primary.

Seven patients with metastatic breast cancer presenting as gastrointestinal primary are described. These included six gastric and one colonic lesions. None of the patients had known systemic metastases at the time of diagnosis. The mean age at presentation was 66.7 yr (range 55-78). Median interval between breast cancer and gastrointestinal metastasis diagnosis was 6 yr (range 0.25-12.5). Original breast cancer histology included infiltrating lobular cancer (n = 4), infiltrating ductal cancer (n = 1), and a mixed type (n = 2). All patients with gastric involvement presented with epigastric pain and early satiety; the patient with colonic involvement had heme-positive stool. In three cases of gastric tumor and the one case of colonic tumor presentation, a definitive diagnosis of metastatic breast cancer was only confirmed after surgical resection of a presumed primary gastric or colonic malignancy. In the other three cases, pathological diagnostic confirmation was obtained through endoscopic biopsies and comparison to breast biopsy material, and operative treatment was avoided in favor of systemic cytotoxic therapy. The diagnosis was confirmed through similarities between mammary and gastric histopathology with regard to growth pattern, hormone receptor status, or gross cystic disease fluid protein. A high level of suspicion for metastatic breast cancer and a detailed pathological analysis will help avoid unnecessary surgical treatment in patients with a history of mammary carcinoma presenting with a newly diagnosed gastrointestinal neoplasm.

Aged↗
PubMed1997

Liver resection for colorectal metastases.

PURPOSE: More than 50,000 patients in the United States will present each year with liver metastases from colorectal cancers. The current study was performed to determine if liver resection for colorectal metastases is safe and effective and to evaluate predictors of outcome. MATERIALS AND METHODS: Data for 456 consecutive resections performed between July 1985 and December 1991 in a tertiary referral center were analyzed. RESULTS: The perioperative mortality rate was 2.8%, with a mortality rate of 4.6% for resections that involved a lobectomy or more. The median hospital stay was 12 days and only 9% of patients were admitted to the intensive care unit. The 5-year survival rate is 38%, with a median survival duration of 46 months. By univariate analysis, nodal status of the primary lesion, short disease-free interval before detection of liver metastases, carcinoembryonic antigen (CEA) level greater than 200 ng/mL, multiple liver tumors, extrahepatic disease, large tumors, or positive resection margin was predictive of poorer outcome. Sex, age greater than 70 years, site of primary tumor, or perioperative transfusion was not predictive of outcome. By multivariate analysis, positive margin, size greater than 10 cm, disease-free interval less than 12 months, multiple tumors, and extrahepatic disease were independent predictors of poorer outcome. Short disease-free interval or multiple tumors were nevertheless associated with a 5-year survival rate greater than 24%. CONCLUSION: Liver resection for colorectal metastases is safe and effective therapy and currently represents the only potentially curative therapy for metastatic colorectal cancer. The only absolute contraindication to resection is extrahepatic disease. A randomized trial to examine efficacy of surgical resection cannot ethically be performed. Liver resection should be considered standard therapy for all fit patients with colorectal metastases isolated to the liver.

Adult↗
PubMed1996

Erythromycin stimulates gastric emptying after esophagectomy with gastric replacement: a randomized clinical trial.

UNLABELLED: Delayed gastric emptying after esophagogastrectomy can pose a significant early postoperative problem. Because erythromycin, which stimulates the gastric antral and duodenal motilin receptor, has been shown to significantly increase gastric emptying in patients with diabetic gastroparesis, we decided to evaluate its effect on gastric emptying after esophagogastrectomy. METHODS: Twenty-four patients (18 men and six women, age range 41 to 79 years, median 66 years) were randomized to receive either erythromycin lactobionate (200 mg in 50 ml normal saline solution intravenously) (n = 13) or placebo (50 ml normal saline solution intravenously (n = 11) 11 days after esophagogastrectomy (with pyloric drainage procedure). After erythromycin or placebo had been infused over a 15-minute period, patients ingested a solid meal (scrambled egg with bread) labeled with technetium 99m sulfur colloid (500 microCi) over approximately 15 minutes. Dynamic images of the stomach were then acquired over 90 minutes in the supine position by gamma imaging. Results were expressed as percentage of counts retained in the stomach (percent gastric retention) over time. RESULTS: There were no side effects of erythromycin. In the placebo group, the mean percent of radiolabeled meal retained in the stomach after 90 minutes was 88%, which was significantly greater than in the erythromycin group, 37% (p < 0.001). In addition, analysis of covariance demonstrated that the rate of gastric emptying (slope of the line) was significantly greater in the erythromycin-treated group than in the placebo group (p < 0.0001). CONCLUSION: Early satiety after esophagogastrectomy may be due to delayed gastric emptying and not due to a decrease in the gastric reservoir. Intravenous erythromycin significantly improves gastric emptying in patients after esophagogastrectomy by stimulating gastric motility.

Adult↗
PubMed1996

The value of minimal access surgery in the staging of patients with potentially resectable peripancreatic malignancy.

OBJECTIVE: The purpose of this study was to determine if an endosurgical approach that mimics open exploration would improve the accuracy of simple diagnostic laparoscopy. SUMMARY BACKGROUND DATA; Most patients with peripancreatic malignancy are found at exploration to be unable to undergo resection. Laparoscopy has been suggested as a sensitive method for detecting metastatic disease in this group of patients. However, the ability to assess resectability with simple diagnostic laparoscopy remains relatively low (<40%). METHODS: Between December 1992 and August 1994, 115 patients with radiologically resectable peripancreatic tumors underwent extended laparoscopy before undergoing a planned curative resection. This technique required assessment of the peritoneal cavity, liver, lesser sac, porta hepatis, duodenum, transverse mesocolon, and celiac and portal vessels. RESULTS: Sixty male and 55 female patients were included in the current study. The pancreatic head was involved in 74 patients (64%), followed by the body in 21 (18%), tail in 8 (7%), ampulla in 8 (7%), duodenum in 3 (3%), and distal bile duct in 1 (1%). An abdominal computed tomography (CT) scan was performed for all patients before laparoscopy, ultrasonography for 74 patients (64%), endoscopic retrograde choleangiopancreatography for 59 patients (51%), and mesenteric angiography for 9 patients (8%). Pneumoperitoneum was established successfully in all but 2 cases (98%). A complete examination of 108 patients was performed. Sixty-seven patients were considered to have resectable disease, and 61 resections were performed. Laparoscopy failed to identify hepatic metastases in 5 patients and portal venous encasement in 1 patient. Unresectable disease was identified in 41 patients. Hepatic metastases were observed in 20 patients, mesenteric vascular encasement in 14, extrapancreatic/peritoneal involvement in 16, and celiac or portal lymphatic metastases in 8. There were no intraoperative or postoperative complications related to the laparoscopic procedure. The positive predictive index, negative predictive index, and accuracy of laparoscopy were 100%, 91%, and 94%, respectively. CONCLUSIONS: This study demonstrates that extended laparoscopy is accurate and safe and makes exploration unnecessary in many patients with potentially resectable peripancreatic malignancy. In this series, 76% of patients explored were resected, compared with the authors' experience between 1983 and 1993 of 35%. The authors believe that laparoscopy is an important component in the staging of this group of patients and should be performed before exploration.

Adult↗
PubMed1994

Options in the surgical treatment of esophageal carcinoma.

A single accepted approach for esophageal excision and reconstruction has not yet been devised. The authors describe the options in surgical approaches available for esophageal resection when dealing with carcinoma and discuss the extent of esophageal resection and lymph node dissection, the conduit, and routes of reconstruction.

Anastomosis, Surgical↗
PubMed1991

Arterial hemorrhage after pancreatoduodenectomy. The 'sentinel bleed'.

Experienced centers report reduced operative mortality after pancreatoduodenectomy for cancer, but significant complications continue to occur in as many as 25% of patients. Anastomotic disruption leads to sepsis in the pancreatic bed where major vascular structures have been exposed by regional lymphadenectomy, creating a setting for arterial erosion or ligature slough and massive hemorrhage. Dehiscence of the pancreatojejunostomy is a particular risk. We treated five patients with arterial hemorrhage after pancreatoduodenectomy, all of whom had had "sentinel" bleeding from the abdominal drains or gastrointestinal tract. Results of endoscopy were misleading in two patients. Three of five patients were saved by prompt recognition, early operation, and, in one instance, angiographic embolization. Sentinel bleeding after pancreatoduodenectomy indicates local sepsis and probable anastomotic dehiscence. Recognition of its significance and prompt response may prevent exsanguination.

Aged↗
PubMed1991

Upper abdominal cancer surgery in the very elderly.

From January 1981 to December 1987, 59 major upper abdominal operations were performed on 57 patients aged 80 to 90 years at Memorial Sloan-Kettering Cancer Center. Procedures for primary adenocarcinoma of the stomach, distal esophagus, pancreas, or hepatobiliary system were performed with curative intent or for palliation in 34 of 59 patients (58%) and bypass with limited or no resection in 13 of 59 patients (22%) patients. Emergency operations were performed in six (10%) patients for gastric bleeding, perforation, or outlet obstruction. Six (10%) patients underwent laparotomy for benign biliary obstruction (1), splenectomy for secondary thrombocytopenia (2), or gastrectomy for sarcoma (2) or lymphoma (1). Hospital mortality was 15% overall and 9% for major resections, 15% for bypass, and 67% for emergency procedures. Major complications occurred in 10 (20%) elective procedures. Mortality was associated with respiratory or cardiac failure while complications most commonly included arrhythmias and wound infection. Mean postoperative hospitalization was 18 days overall and 45 patients (76%) were discharged home. Median survival following major resection was 17.5 months but less than 2 months after bypass procedures. A protocol of pre-operative evaluation, intra-operative hemodynamic monitoring and postoperative intensive care has been formalized for use in elderly or poor-risk patients.

Adenocarcinoma↗
PubMed1990

Adrenal insufficiency in the cancer patient: implications for the surgeon.

Aspects of acute and chronic adrenal insufficiency of interest to surgeons who treat cancer patients are reviewed. Clinical features and the management of both primary and secondary types are considered with reference to classification, aetiology, diagnosis and treatment. Specifically considered are the management of patients with Addison's disease and metastases. Prompt recognition and treatment of adrenal insufficiency can avert potentially life-threatening situations.

Acute Disease↗
PubMed1990

Recurrence of resected esophagogastric adenocarcinoma: results of re-resection.

Isolated local recurrence following potentially curative resection for carcinoma of the esophagus or esophagogastric junction does not necessarily imply pending systemic disease and early demise. While radiation alone or in combination with chemotherapy is standard treatment for such patients, resection is another available option. Resection may also be a consideration should localized disease persist after non-operative therapy in the absence of metastases. A 5 year retrospective review was performed examining 204 resections performed prior to 1989. Only 5 patients underwent resection of locally recurrent esophagogastric (EG) adenocarcinoma during this period. No squamous carcinoma recurrences were resected. One patient is well 15 months later while another died at 18 months of other causes without recurrence. Recurrence after re-resection occurred at 8, 11, and 24 months in the 3 other patients. Although there were no postoperative deaths, major complications occurred in 4 patients. All 5 patients swallowed normally after operation.

Adenocarcinoma↗
PubMed1989

Spontaneous gastroduodenal perforation in cancer patients receiving cytotoxic therapy.

Spontaneous gastroduodenal perforation (SGDP) occurs in cancer patients receiving cytotoxic drugs, corticosteroids, or radiation therapy as primary or adjuvant treatment for their tumors. A retrospective review identified 12 patients from 1974 to 1987 at the Memorial Sloan-Kettering Cancer Center who underwent surgery for SGDP while receiving anticancer therapy. There were five gastric and seven duodenal perforations. Vague abdominal pain was the most common symptom. Exploration was delayed in six patients because of an absence of physical findings. All patients received a Graham omental patch. The in-hospital operative mortality was 33%, with all major complications occurring in those that died. There were no prognostic indicators identified that would preoperatively predict outcome. Aggressive surgical intervention is advised in all patients who have a reasonable chance of worthwhile palliation if not cure.

Adrenal Cortex Hormones↗
PubMed1989

Isolated breast metastases from gastrointestinal carcinomas: report of two cases.

Two patients with metastatic gastrointestinal adenocarcinoma in the breast are reported. Metastases in the breast are usually painless upper outer quadrant masses. On mammography they are typically well-circumscribed lesions without microcalcifications. A breast mass in a patient with a history of cancer, even if clinically or mammographically benign, should raise suspicion of a metastasis. Pathological features include a histologic pattern similar to the primary neoplasm and an absence of in situ carcinoma which characterizes primary breast cancer. Surgical excision for local control and systematic therapy is the most appropriate treatment.

Adenocarcinoma, Mucinous↗
PubMed1989

Results of surgery for obstructing carcinomatosis of gastrointestinal, pancreatic, or biliary origin.

Results of operation for obstructing carcinomatosis of gastrointestinal (GI), pancreatic, or biliary origin were reviewed to assess relief of symptoms, management of re-obstruction, and duration of hospitalization. A retrospective review (1977 to 1986) identified 89 patients, 59 (66%) of whom had tumors originating in the colon, and 19 (21%) in the stomach. Normal bowel function was restored for a median of 102 days in 66 patients (74%) and all but four (94%) were discharged. Forty-one (46%) patients remained unobstructed until death. Twenty-three (26%) were not relieved by operation and died a median of 33 days later (P less than .005). Forty-eight (81.4%) of the 59 colon cancer patients and ten (52.6%) of 19 with gastric cancer (P less than .05) were benefited by the operation, although comparison of duration of function was less striking (P less than .1). In-hospital mortality was 13% and complications occurred in 44%. Obstruction recurred in 38% of those relieved by the initial operation. Normal bowel function was restored in six (46%) of 13 patients undergoing a second laparotomy (median, 158 days) and in six of 13 (46%) treated with nasogastric suction. Obstruction recurred again in four of the latter six patients (median, 39 days). Hospitalization averaged 31 days (median, 25 days) for the first procedure and 41 days (median, 39 days) for patients operated for recurrent obstruction. These results justify laparotomy for intestinal obstruction in known or suspected carcinomatosis, particularly of colonic origin, if performance status is compatible with a reasonable quality of life.

Adenocarcinoma↗