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Biomedical subjects

K C Westbrook

Publications and source records attributed to K C Westbrook.

At least 19 recordsLinked to original sources
PubMed1994

Prevention of chronic radiation enteropathy by dietary glutamine.

BACKGROUND: Nearly 50% of all cancer patients receive therapeutic radiation during the course of their disease. The risk of late complications is the main dose-limiting factor in the delivery of radiation therapy. The small intestine, the major site of chronic radiation enteropathy, is also the principal organ of glutamine consumption. We therefore hypothesized that the provision of supplemental glutamine may have a protective effect on the development of chronic radiation enteropathy. METHODS: This study evaluated the effects of supplemental oral glutamine on the development of chronic radiation (XRT) enteropathy. After scrotalization of a loop of small intestine, rats were randomized to receive 1 g/kg/day glutamine (GLN) or glycine (GLY) by gavage. After 2 days of prefeeding, rats were randomized to 1 of 4 groups: GLN + XRT (n = 10), GLY + XRT (n = 10), GLN only (n = 10), GLY only (n = 10). Twenty Gy was delivered to the scrotalized bowel in the GLN + XRT and GLY + XRT groups via a collimated beam. Gavage was continued for 10 days. Animals were then pair-fed chow. Rats were killed at 2 months postirradiation. Chronic radiation injury was assessed microscopically. RESULTS: Injury scores in GLN + XRT were similar to those of unirradiated bowel and significantly different from GLY + XRT (1.89 +/- 0.48 in XRT + GLN vs. 6.42 +/- 1.55 in the XRT + GLY, p < 0.01). Elevated Injury Scores in the XRT + GLY group correlated with gross thickening and fibrosis, a 10-fold decrease in gut GLN extraction (1.40 +/- 4.3% in GLY + XRT vs. 16.0 +/- 5.1% in GLN + XRT, p < 0.05), and a 30% decrease in glutathione content (2.46 +/- 0.19 and GLY + XRT vs. 3.17 +/- 0.17 GLN + XRT, p < 0.05). CONCLUSIONS: Provision of GLN during abdominal/pelvic XRT may prevent XRT injury and decrease the long-term complications of radiation enteropathy.

Administration, Oral↗
PubMed1992

Effect of supplemental dietary glutamine on methotrexate concentrations in tumors.

This study evaluated the effects of supplemental dietary glutamine (GLN) on methotrexate sodium concentrations in tumors and serum of sarcoma-bearing rats following the initiation of methotrexate. After randomization to a GLN diet (+GLN) or GLN-free diet (-GLN), tumor-bearing rats received 20 mg/kg of methotrexate sodium by intraperitoneal injection. The provision of supplemental GLN in the diet increased methotrexate concentrations in tumor tissues at 24 and 48 hours (38.0 +/- 0.20 nmol/g for the +GLN group vs 28.8 +/- 0.10 nmol/g for the -GLN group and 35.6 +/- 0.18 nmol/g for the +GLN group vs 32.5 +/- 0.16 nmol/g for the -GLN group, respectively). Arterial methotrexate levels were elevated only at 48 hours (0.147 +/- 0.007 microns/L for the +GLN group vs 0.120 +/- 0.006 microns/L for the -GLN group). Tumor morphometrics were not different between the groups but significantly greater tumor volume loss was seen even at 24 hours (-2.41 +/- 1.3 cm3 for the +GLN group vs -0.016 +/- 0.9 cm3 for the -GLN group). Tumor glutaminase activity was suppressed in both groups at 48 hours, but more so in the +GLN group (0.94 +/- 0.13 mumol/g per hour for the +GLN group vs 1.47 +/- 0.22 mumol/g per hour for the -GLN group). This study suggests that GLN may have therapeutic as well as nutritional benefit in oncology patients.

Animals↗
PubMed1992

Advantages of the Papillon protocol in the preoperative treatment of rectal carcinoma.

Standard treatment for advanced rectal carcinoma currently includes surgery, radiotherapy, and chemotherapy. Although there are theoretic advantages to preoperative irradiation, it is often not performed because of the prolonged delay of surgery and the purported increase in perioperative complications. A pilot study was undertaken at our institution to evaluate a treatment protocol advocated by Dr. Papillon that offers a shorter treatment time and less patient morbidity than conventional preoperative therapy for rectal carcinoma. Twenty patients with rectal cancer underwent the preoperative regimen that consisted of 3,000 cGy delivered in 10 fractions over 12 days with concomitant 5-fluorouracil and mitomycin-C. Complications were acceptable. Local recurrence was lower than in most reported trials, and survival rates were comparable. Additional benefits of the protocol include lower radiation morbidity to the patient and a decreased delay between diagnosis and surgery.

Adenocarcinoma↗
PubMed1991

Prognostic significance of carcinoembryonic antigen in colorectal carcinoma. Serum levels before and after resection and before recurrence.

The use of carcinoembryonic antigen was evaluated in 425 patients with a mean follow-up of 48 months. The preoperative and postoperative carcinoembryonic antigen levels were predictive of recurrence and survival independent of the tumor stage. In a multivariate regression analysis of age, location, tumor stage, and preoperative and postoperative carcinoembryonic antigen levels, the latter three factors were significant prognostic variables with respect to the adjusted survival. Recurrent disease was found in 42% of patients, excluding patients with stage IV disease. The carcinoembryonic antigen level at recurrence was greater than 5 ng/mL in 79% of the patients and in 89% of the intra-abdominal recurrences. Carcinoembryonic antigen level at recurrence was not predictive of postrecurrence survival except in the subgroup of locoregional disease. The life span in patients with liver and lung metastases was not influenced by carcinoembryonic antigen level at recurrence. Preoperative and postoperative carcinoembryonic antigen levels can indicate a poorer prognostic group of patients with colorectal cancer who may benefit from adjuvant treatment. The carcinoembryonic antigen at recurrence can be used effectively to diagnose intra-abdominal recurrences and project survival after development of local/regional disease.

Aged↗
PubMed1990

Breast cancer.

Breast cancer will affect 1 out of 10 women in the United States and cause 27 deaths per 100,000 women per year. The etiology remains unknown, but the incidence correlates with genetic as well as environmental factors. Screening programs have been shown to prolong the survival by early detection compared with control populations but remain underutilized by physicians and patients. Breast disease can be evaluated by physical examination and mammography and a definitive diagnosis made by needle aspiration, needle biopsy, or excisional biopsy. This allows the patient to participate in the decision regarding mastectomy vs. conservative surgery plus radiation therapy. These two approaches have equivalent survival in selected patients. Patients with locally advanced, nonmetastatic disease benefit from a multidisciplinary approach using preoperative chemotherapy and postoperative radiation therapy. This approach has allowed less disfiguring surgery and improved survival. Preinvasive carcinoma is diagnosed more frequently with the increased use of screening mammography. Local therapy options include simple mastectomy, local excision plus radiation, or local excision alone. The natural history and results of therapy in preinvasive disease are evolving as more data are accumulated. Systemic adjuvant therapy is recommended for all node-positive patients and most node-negative patients with invasive cancer. The specific modality (hormonal or cytotoxic) varies with the subgroup involved. Treatment of metastatic disease to palliate symptoms and prolong survival includes the use of local therapies (surgery and radiation) and hormonal and cytotoxic agents. Most patients benefit, but cure has been unobtainable. Newer approaches utilizing high-dose chemotherapy and bone marrow support with growth factors or autologous transplantation are currently being explored.

Breast Neoplasms↗
PubMed1989

Peritoneal carcinomatosis in nongynecologic malignancy. A prospective study of prognostic factors.

Regional recurrence of malignant tumors in the peritoneal cavity usually signifies a poor prognosis for the host and often results in gastrointestinal complications requiring surgical intervention. One hundred patients with nongynecological malignancies found with peritoneal carcinomatosis were followed prospectively. The most common primary tumors were colorectal (N = 45) and pancreatic (N = 20) carcinoma. When associated with pancreatic carcinoma, 65% of patients had liver metastases and 60% had ascites. The presence of ascites was associated with poor survival, with no patient surviving past 30 days. Ascites was also a sign of poor prognosis in patients with colorectal carcinoma. Among possible prognostic factors in colorectal carcinoma patients, only disease-free interval, presence of lung metastases, and ascites showed statistically significant correlations with survival. Peritoneal carcinomatosis in sarcoma (N = 7) and breast cancer (N = 6) patients had median survival of 12 and 7 months, respectively. Surgical intervention for gastrointestinal complications in peritoneal carcinomatosis can provide significant palliation, with a few exceptions such as in patients with pancreatic or gastric carcinoma, ascites, and poor performance status.

Adult↗
PubMed1987

The current evaluation of nonpalpable breast lesions.

To understand the suspected low yield of malignant neoplasms from biopsies guided by needle localization, we reviewed 122 biopsies performed from January 1985 to November 1986 at University Hospital and Arkansas Baptist Medical Center, Little Rock. The positive biopsy rates were 3.5% and 10.6%, respectively. After review of these cases, the following guidelines for biopsy were developed: (1) Do not perform a biopsy on a low-density mass less than 1 cm in diameter. (2) Do not perform a biopsy for asymmetric density or questionable mass. (3) Do not perform a biopsy for secondary signs of malignancy such as skin thickening or asymmetric vasculature. (4) Biopsy is indicated for clustered calcifications, a dominant mass greater than 1 cm in diameter, stellate lesions, or interval change from a previous mammogram. These changes resulted in a positive biopsy rate of 15% for the period from November 1986 through April 1987.

Biopsy, Needle↗
PubMed1986

Precise intraoperative location of gastrointestinal bleeding with a hand-held counter. Work in progress.

The nuclear medicine bleeding scan is frequently insufficient to locate sites of bleeding precisely, in spite of its great sensitivity. A small, hand-held Geiger-Müller counter, placed directly on exposed intestine in the operating room, enables precise location of the probable bleeding site. In three patients, the technique allowed a minimal amount of intestine to be resected, distinguished between large- and small-intestinal hemorrhage, and eliminated other foci as sites of bleeding.

Gastrointestinal Hemorrhage↗
PubMed1985

Clinical oncology assistantship program for medical students.

The Clinical Oncology Assistantship Program has been offered to approximately 16 sophomore medical students each year at the University of Arkansas for Medical Sciences since 1975. This is an elective, 10-week program given during the summer recess. In the first week of the program, core lectures are given by a multidisciplinary team of cancer educators affiliated with the University of Arkansas. Following this, students spend nine weeks rotating through medical, surgical, and pediatric oncology services of the University of Arkansas for Medical Sciences. In addition, they spend several hours during the program participating in self-directed learning activities at the university's Cancer Teaching Center. The program has been well received by the students, and each year all of the available positions have been filled. Responses on a follow-up questionnaire sent in July 1983 to past participants showed that they continued to rate the program highly. Moreover, 78 percent of the respondents felt the program had influenced positively their attitude toward cancer patients.

Arkansas↗
PubMed1985

Use of intraoperative radionuclide study and colonoscopy in gastrointestinal hemorrhage.

Tc-99m labeled red cell imaging is used in the diagnosis and localization of gastrointestinal hemorrhage. A patient in whom a preoperative scan was positive in the right paraumbilical region is discussed. Intraoperative Tc-99m labeled red cell imaging was used in conjunction with colonoscopy, and the site of active bleeding was found in the proximal transverse colon, which had been displaced downward because of adhesions.

Colonoscopy↗
PubMed1984

Melanoma today does not require radical surgery.

From this study we conclude that melanoma has a more favorable outcome today than 20 years ago, 2 cm margins around the tumor achieve acceptable survival and local recurrence rates, primary closure is preferred when possible, elective regional node dissection is of questionable value, and further trials are warranted to determine optimal therapy for intermediate thickness melanoma.

Adult↗
PubMed1984

Bile drainage through lymphatic collaterals.

Bile drainage through normal lymphatic pathways has been described, but bile drainage from the liver to the duodenum via lymphatic collaterals has not. We have described a patient with a common bile duct stricture and lymphatic drainage of bile into the duodenum.

Adult↗
PubMed1983

Can patients with breast cancer be cured of their disease? A sample of the M. D. anderson Hospital experience.

Theories concerning cures for breast cancer vary from the concept that no patients are cured, to the idea that the hazard to patients who have survived eight years is no greater than that for the population as a whole. To test these concepts as well as our modification of the concept of cure, we assumed that a proportion (P) of the population of patients is cured and have the same mortality experience as that for the population as a whole. The remaining proportion Q = 1 - P experience mortality as do the population and also that due to cancer. The hazard rate due to cancer is assumed to be constant. When survival experience for the 804 female patients with breast cancer admitted during 1958 through 1960 and that predicted from our model are plotted, the fit is excellent, particularly for survivals up to 15 years. As to whether some patients with breast cancer are cured of their disease, the answer is yes, using our definition of cure.

Adult↗
PubMed1982

Primary malignant retroperitoneal tumors. Current management.

Our experience with 16 retroperitoneal tumors seen over a 13 year period has been reported. Patients presented with either an abdominal mass or abdominal pain associated with a large retroperitoneal tumor. Delineation of the tumor is best accomplished with computerized tomography and venacavography. Exploration and resection is possible in most patients. Postoperative radiotherapy and chemotherapy are recommended in most patients. Local recurrence frequently occurs and should be diagnosed early and resected aggressively if found.

Adult↗