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A T Lefor

Publications and source records attributed to A T Lefor.

48 records · Page 3Linked to original sources
PubMed1988

Analysis of chromium-51 release assay data using personal computer spreadsheet software.

The Chromium-51 release assay is a widely used technique to assess the lysis of labeled target cells in vitro. We have developed a simple technique to analyze data from Chromium-51 release assays using the widely available LOTUS 1-2-3 spreadsheet software. This package calculates percentage specific cytotoxicity and lytic units by linear regression. It uses all data points to compute the linear regression and can determine if there is a statistically significant difference between two lysis curves. The system is simple to use and easily modified, since its implementation requires neither knowledge of computer programming nor custom designed software. This package can help save considerable time when analyzing data from Chromium-51 release assays.

Chromium Radioisotopes↗
PubMed1987

Effect of anti-B16 melanoma monoclonal antibody on established murine B16 melanoma liver metastases.

The administration of anti-B16 monoclonal antibody of the IgG2b isotype to mice bearing established B16 melanoma liver metastases caused a significant and consistent reduction of up to 90% in the number of these metastases. No reduction in the number of metastases was noted when antigenically unrelated tumor or nonspecific immunoglobulin were employed. The antibody-mediated antitumor effect was completely abrogated by total body irradiation of the host. Treatment of the tumor-bearing host with antiserum directed against asialo GM1 prior to anti B16 antibody administration, abrogated the therapeutic effect indicating the involvement of a radiosensitive, ASGM1-positive cell in the tumor regression. The antitumor effect of the antibody treatment could be augmented by the concomitant administration of recombinant interleukin-2. The effect seen may have possible application in the treatment of liver metastases in humans by combined immunotherapy using recombinant interleukin-2 and specific antitumor monoclonal antibodies.

Animals↗
PubMed1986

Multiple malignancies of the lung and head and neck. Second primary tumor or metastasis?

Independent primary cancers of the head and neck and of the lung may be confused with lung metastases from a head and neck tumor. We retrospectively reviewed the cases of 55 patients who had head and neck malignancies and pulmonary lesions. To distinguish between independent primary tumors and lung metastases we applied an algorithm using the following criteria: sequence of appearance of the lesions; tumor histology; radiologic appearance of the lesions; and presence of malignant anterior cervical adenopathy. In this group of 55 patients, 40 were categorized as having independent primary malignancies and 15 were categorized as having pulmonary metastases from the head and neck tumor. In cases in which the origin of the pulmonary lesion is unclear, the patient should be treated as though independent primary malignancies were present since this offers the best chance for cure.

Carcinoma, Squamous Cell↗
PubMed1985

The effects of hyperthermia on vascular permeability in experimental liver metastasis.

The effects of hyperthermia on vascular permeability in Walker carcinosarcomas and host liver tissue were studied in Sprague-Dawley rats. A quantitative Evans blue technique was used to measure permeability. With tumors heated to 40 degrees C, a nontherapeutic level, no changes in tumor vascular permeability as compared to control levels were noted. However, with tumors heated to 43 degrees C, within the therapeutic range of hyperthermia, significant rises in tumor vascular permeability occurred. Permeability was increased at both time periods studied, 30 minutes and 6 hours after hyperthermia and injection of Evans blue. These changes are similar to those seen after physical damage from freeze-thaw. It is likely that alterations in tumor microcirculation play a role in the therapeutic effect of intense hyperthermia.

Animals↗
PubMed1984

Needle localization of occult breast lesions.

Excision of mammographically demonstrated breast lesions that are clinically occult remains a surgical challenge. Eighteen lesions were preoperatively localized (all but 1 with the Frank hooked wire technique). Eleven lesions were evaluated with specimen radiography. Three lesions proved to be malignant at biopsy and 15 were benign. We found hooked wire needle placement to be extremely accurate, enabling rapid excision of the suspicious mass with excision of rather small areas of the breast with no significant cosmetic defect. Mean anesthetic time for breast biopsy alone was slightly less than time for biopsy with needle localization, which was less than that when specimen radiography was employed. In the absence of a discrete lesion, specimen radiography is a useful adjunct. Needle localization is simple, accurate, rapid, and requires no special apparatus. Its widespread use should lead to the identification of more breast carcinomas in a potentially curable state.

Adult↗
PubMedDate not supplied

Laparoscopic evaluation of lymphoma.

Surgeons are involved in the diagnosis and staging of patients with lymphoma. Treatment requires accurate information about histologic classification and the extent of disease. While most patients with non-Hodgkin's lymphoma are treated with systemic chemotherapy, the exact stage of disease in patients with Hodgkin's lymphoma may determine the therapy to be used. The use of minimally invasive surgery in surgical staging of patients with Hodgkin's disease has the potential to decrease the morbidity and mortality of the staging procedure in these patients. All of the components of a staging procedure (liver biopsies, splenectomy, lymph node biopsies, and oophoropexy) can be performed laparoscopically. The procedure is performed with the patient in the supine position. After obtaining several liver biopsies, the splenectomy is completed. Lymph nodes are then sampled from the celiac, portal, iliac, and peri-aortic regions. Lymph nodes identified as abnormal on pre-operative imaging studies are identified and excised. While each of these procedures is technically challenging, the laparoscopic conduct of this diagnostic procedure may afford patients decreased post-operative morbidity and mortality.

Biopsy↗
PubMedDate not supplied

Gastric outlet obstruction secondary to post cholecystectomy biloma: case report and review of the literature.

BACKGROUND: Postcholecystectomy bilomas are relatively uncommon with a reported incidence of about 2.5%, and most often present with right upper quadrant pain and fever within seven days of the operation. There are a number of approaches to the treatment of this uncommon lesion. CASE REPORT: The authors report a case of a cholecystectomy performed in a 35-year-old female which resulted in a biloma, presenting 11 days postoperatively with gastric outlet obstruction. The literature is reviewed to suggest the optimal management and treatment plans for this complication. RESULTS: This patient was successfully managed with radiologic intervention for the treatment of a biloma and resulting gastric outlet obstruction after open cholecystectomy. CONCLUSION: Although uncommon, bilomas may present in an unusual manner such as with gastric outlet obstruction. As with early bilomas, they may be treated successfully with interventional radiologic techniques.

Adult↗