Search PubMed⌕ Search

Biomedical subjects

A S Ketcham

Publications and source records attributed to A S Ketcham.

At least 55 records · Page 3Linked to original sources
PubMed1979

Flow cytometry: general principles and applications to selected studies in tumor biology.

The cell populations derived from normal tissues and solid tumors comprised many different cell types. Within each cell type there is a distribution of cells in different phases of the cell cycle and/or metabolic states (ie, differing rates of protein, RNA, and other macromolecular syntheses). Flow cytometry and companion instrumentation now promise to aid in rapid quantitative analyses of heterogeneous cell populations, thus finding broad applicability in many areas of cancer research and treatment. Since it is projected that this analytical technique will greatly expend our knowledge in tumor biology, it seems appropriate to review the basis principles of the methodology and to demonstrate recent applications in several areas of current research. After reviewing basis principles, a detailed description of one specific flow cytometer, the PHYWE-ICP-22, with its computer interface as developed in this laboratory is described. Subsequently, applications of this methodology to analyses of tumor cell kinetics, assays of blastogenesis, and studies of human colon cancer are presented as specific, current applications of flow cytometry. It is anticipated that this overview of flow cytometry along with some current applications will provide a background understanding for the inevitable rapid future developments in this area of research.

Animals↗
PubMed1978

Lung tomography in cancer patients. Full-lung tomograms in screening for pulmonary metastases.

In a retrospective study of the cases of 415 patients with various malignant neoplasms, full-lung tomography and conventional chest roentgenography were compared for accuracy in the detection of pulmonary metastases. Sufficient information was available on 410 patients to permit confirmation as to whether pulmonary metastases were present at the time of screening chest roentgenographic and tomographic examinations. On screening by routine chest roentgenography, metastases were detected in 36 patients, 66.7% of the total with confirmed metastatic disease. Screening by full-lung tomography identified metastases in 51 (94.4%). Fifteen patients with normal chest roentgenograms had metastatic lesions on tomograms. Metastases were detected in 8.8% by chest roentgenograms and in 12.4% by tomograms in a population of cancer patients with a 13.2% incidence of pathologically confirmed metastatic lesions.

Adolescent↗
PubMed1978

Osteosarcoma: improved survival with anticoagulation and amputation.

A study of warfarin anticoagulation as an adjunct to amputation of osteosarcomas was undertaken after finding dramatic results in experimental systems. Anticoagulation was started 7 days preoperatively, continued during the operation, and for up to six months postoperatively. Three of 21 (14%) non-anticoagulated control patients are alive at 5-11 years. Five of 9 (56%) of the anticoagulated patients remain alive 5-8 years. The presumed mechanism of increased survival is an inhibition of fibrin deposition around circulating tumor cells, thereby preventing their adherence to capillary endothelium to initiate metastasis formation.

Adolescent↗
PubMed1978

Osteosarcoma associated with Thorotrast administration: report of two cases and literature review.

Two cases of osteosarcoma are described arising in patients who had undergone angiography with Thorotrast during childhood. In both patients, there was radiographic and pathologic evidence of radioactive thorium dioxide deposition in bone as well as throughout the reticuloendothelial system. Thorotrast deposits were demonstrated in the immediate vicinity of the primary tumors by both histology and autoradiography. Previous cases of osteosarcoma associated with Thorotrast administration from the literature are cited, and possible causal relationships are discussed between thorium retention in bone and neoplastic transformation by chronic radiation.

Adolescent↗
PubMed1978

Excretory urography in evaluation of the surgical cancer patient.

Excretory urography was performed routinely in 504 patients with sarcoma, melanoma, pelvic, head and neck, or other localized tumors over a 5-year period. There were benign abnormalities in 14.4% of the patients examined, tumor associated abnormalities in 10.7%, and 1.4% false positives. The diagnosis of a benign lesion did not change cancer therapy in any patient. Findings on excretory urography were valuable in the management of patients with pelvic and intra-abdominal tumors. In these patients ureteral obstruction was always caused by tumor. There was a high rate of false positively in non-abdominal tumors. No second primary tumors were found.

Abdominal Neoplasms↗
PubMed1978

Antibiotic concentration in human wound fluid after intravenous administration.

Since the wound is the most common focus of infection in the surgical patient, adequate levels of antibiotic within the wound ar essential. This study examines the concentrations of antibiotic achieved in human wounds. Fluid was collected at timed intervals on the first postoperative day from the wounds of 56 patients receiving antibiotics after regional lymph node dissection. Antibiotic concentration was determined by bioassay. Six antibiotics were studied: cephalothin, cefazolin, cephapirin, oxacillin, ampicillin and clindamycin. The cephalosporins and penicillins showed similar patterns of appearance in the wound fluid. The peak level occurred early (1--1 1/2 hours) with subsequent slow decrease. Clindamycin produced nearly constant levels in wound fluid. The concentration of each antibiotic in wound fluid surpassed the serum levels after 2.5 hours. At the dosages studied each antibiotic produced wound fluid concentrations greater than the MIC for most susceptible organisms. Higher doses provided higher wound fluid levels. The rate of appearance and the levels achieved should be considered in the choice of antibiotics in the surgical subject.

Anti-Bacterial Agents↗
PubMed1977

Barium enema, proctosigmoidoscopy and upper gastrointestinal series in the preoperative evaluation of the cancer patient.

Charts of 566 patients admitted to the Surgery Branch, National Cancer Institute over a five year period were reviewed. Routine upper gastrointestinal series was performed in 453 patients; barium enemas in 490; and proctosigmoidoscopies in 342. Upper gastrointestinal series detected no metastases or second primary malignancies but delineated the extent of large intra-abdominal tumors. Barium enema and proctosigmoidoscopy together revealed three unsuspected primary colonic tumors (1.2% in patients over 50 years of age). Sigmoidoscopy and examination of the stool for occult blood would have detected the same patients. Barium enema may be limited to surgical cancer patients in whom the extent of local tumor invasion is to be defined and to older patients in whom colonic tumors are suspected. Neither UGIS nor barium enema appear to be of value as a routine preoperative screening test in surgical cancer patients.

Adolescent↗
PubMed1977

Prognostic factors in patients undergoing lymphadenectomy for malignant melanoma.

Review of a 19 year experience in melanoma patients undergoinglymphadenectomy at the National Cancer Institute revealedthat the preoperative assessment of the status of theregional lymph nodes was accurate 91% of the time when thesurgeon felt the nodes were clinically positive, and accurate79% of the time when the nodes were judged clinically negative. The 10-year survival in patients with one to three histologicallypositive nodes or no positive nodes was 50-55%, compared to a25% 8-year survival in patients with four or more histologicallypositive nodes. Stepwise multivariate evaluation of prognosticfactors indicated that the most important factor for predictingprognosis is the number of nodes histologically involved. Nodepalpability was the second most important factor because of itshigh correlation with number of nodes histologically involved. Site of melanoma was the third most important factor, aspatients with extremity (upper or lower) melanoma had a bettersurvival (P = 0.002) than patients with axial melanoma (trunkor head and neck). Five years following lymphadenectomythere appeared to be substantial differences in survivalaccording to differences in the level of invasion of the primarylesion, however, these differences were not nearly aspronounced 10 years following node dissection.B The division of melanoma thicknesses into <1.50 mm and>1.50 mm provided some prognostic discrimination at fiveyears but again the differences were not pronounced 10 yearsfollowing node dissection. The thickness measurements wereeasier to determine than the level of invasion, and more reproduceableon resubmission to the same pathologist. Fourpatients with melanoma less than 0.76 mm had subsequentmetastases, but these may represent inadequate sampling of theprimary melanoma both in our series and in the four similarpatients previously reported with such thin metastasizingmelanomas.

Female↗
PubMed1977

Mechanisms and prevention of cancer dissemination: an overview.

Synthesizing data from many experimental and clinical courses, a current working model for tumor dissemination has been constructed. Several aspects of this model are being exploited to therapeutic advantage for the patient with cancer. Surgeons should continue to exercise the principles of en bloc tumor resection and employ maneuvers to minimize iatrogenic tumor dissemination .

Animals↗
PubMed1976

Carcinoma in situ of the vagina following treatment for carcinoma of the cervix: a distinctive clinical entity.

A series of 10 patients who presented with carcinoma in situ of the vagina following treatment for carcinoma of the cervix were seen in a 3 year period and their clinical and histologic features reviewed. Vaginal lesions developed 1 to 22 years after diagnosis of carcinoma of the cervix was made. In three patients the vaginal lesions progressed to invasion. In the remaining patients repeated biopsies have revealed persistent carcinoma in situ. From this series of 10 patients we conclude that the biologic behavior of vaginal carcinoma in situ following carcinoma of the cervix resembles that of carcinoma in situ of the cervix and that carcinoma of the vagina following carcinoma of the cervix should be considered a separate clinical entity distinctive from primary invasive carcinoma of the vagina.

Adult↗
PubMed1976

The role of immune factors in the survival of circulating tumor cells.

The effects of immune serum on the survival of hematogenously disseminated malignant cells were investigated in six murine tumor systems with varying immunogenicity. Blood containing circulating tumor cells demonstrable by bioassay was obtained from donor mice with disseminated tumor. The cellular fraction was isolated by centrifugation and resuspended in immune serum obtained from donor animals bearing the same tumor (Group 1), in immune serum from mice bearing a differing tumor (Group 2), or in normal nonimmune serum (Group 3). The mixed cellular and serum fractions were intravenously inoculated into normal recipient mice which were subsequently scored for the development of pulmonary tumors. Similar incidence (35-50%) of pulmonary tumor deposits were seen in Groups 2 and 3. A significant enhancement in the incidence of lung tumors was present in the Group 1 animals for all tumor systems studies. It was suggested that the observed enhancement resulted from factors present in isologous immune serum but absent from both normal serum and immune serum obtained from hosts bearing heterologous tumors.

Adenocarcinoma↗