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Biomedical subjects

A Silvers

Publications and source records attributed to A Silvers.

At least 55 records · Page 3Linked to original sources
PubMed1980

Correlation of histopathologic characteristics of primary tumor and uninvolved regional lymph nodes in Dukes' class C colonic carcinoma with prognosis.

Ninety-two patients with Dukes' class C colonic carcinoma, divided equally into those who survived 5 years or more and those surviving less than 5 years after resection for cure, underwent evaluation of multiple histopathologic characteristics of the primary tumor and the uninvolved regional lymph nodes. These characteristics were analyzed by the chi-square test for correlation with survival. A statistically significant correlation (P less than 0.05) in the group who survived 5 years or more was observed for Broders' grades 1 and 2, tumor not involving serosa, and a pushing tumor margin. Of the 14 patients who had a pushing tumor margin and tumor not involving serosa, 12 (86%) survived 5 years or more. Seven patients had an infiltrating tumor margin and peritumor venous invasion, and of this group, only one (14%) survived 5 years or more. Histopathologic characteristics of host immune reaction at the tumor or in the uninvolved regional lymph nodes did not correlate with survival.

Colonic Neoplasms↗
PubMed1979

Nonspecific immune determinants in the patient with unresectable gastrointestinal carcinoma.

Assays of immune function (recall skin tests to microbial antigens; total circulating lymphocytes, T-cells, B-cells; lymphocyte blastogenesis with PHA, Con A, and pokeweed mitogens; and serum immunoglobulins IgA, IgM, IgG) were obtained in 408 patients with unresectable gastrointestinal carcinoma. The overall patient population, in comparison to normal controls, was characterized by reduced response to recall skin tests, reduced total lymphocyte and T-cell counts, reduced lymphocyte blastogenesis assays, increased B-cell counts and increased IgA and IgM. Significant immunosuppression was associated with prior radiation or chemotherapy, and with impaired patient performance status. There was no apparent correlation between extent of clinically evident malignant disease and immune function within this patient population. No assay of immune function matched the prognostic value of the more readily available and less expensive determinations of performance status, serum alkaline phosphatase, or SGOT. Only reactivity to recall skin tests had a significant correlation to patient survival independent of performance status. Among patients with little or no disability, only intensity of skin test reactivity correlated significantly with survival; and among those with greater disability, there was correlation only with proportion of skin tests positive. The combination of candida and streptokinase antigens provided the best recall skin test survival correlation. Adding a third, fourth, or fifth antigen did not add to prognostic value. From an overall standpoint, the immune determinants which we studied do not appear to provide useful additions to the evaluation of the patient with unresectable gastrointestinal cancer.

Age Factors↗
PubMed1978

A prospective evaluation of the leukocyte adherence inhibition test in colorectal cancer and its correlation with carcinoembryonic antigen levels.

Fifty-four patients from the surgical gastroenterology service and 22 healthy controls have been prospectively evaluated in a single-blind protocol by the LAI tube method. The LAI correctly identified 25 of 33 early colorectal patients staged as Dukes' B and C at surgery but none of the Dukes' D patients. An inverse relationship was seen between the results of the non-adherence index (NAI) and CEA levels which was most pronounced in those with advanced colorectal cancer. The majority of Dukes' B and C patients having a "false negative" LAI had a CEA level greater than 2.5 ng/ml, suggesting that more advanced disease than that seen at surgery may be present. Two of 22 normal controls gave a borderline positive NAI. Some technical problems, including the relatively short life of the tumor extracts, are discussed.

Carcinoembryonic Antigen↗
PubMed1978

Development of a computerised cancer data management system at the Mayo Clinic.

A multidisciplinary team was assembled to design a cancer data management system that would meet the storage, retrieval and analysis NEEDS OF Mayo's clinical trials of anti-tumour drugs. To fulfill these requirements, a computerised data entry and retrieval system was developed, the primary patient health record used by the oncologists was redesigned and the clerical procedures and work flow within the Cancer Center Statistics Office were reorganised. The end result of this project is a system that has: (1) enabled Mayo to meet its reporting requirements as a Comprehensive Cancer Center; (2) provided the statisticians and the physicians with the capacity to perform more detailed and accurate analyses of clinical trials; (3) reduced the clerical effort needed for preparing reports and analyses; (4) provided the potential for expansion to meet the growing requirements of the future and (5) attained that often elusive goal of computer systems--user satisfaction.

Antineoplastic Agents↗
PubMed1978

Serial plasma carcinoembryonic antigen measurements in the management of metastatic colorectal carcinoma.

Serial carcinoembryonic antigen (CEA) measurements were evaluated in a group of 263 patients undergoing systemic chemotherapy for metastatic colorectal carcinoma. Initial CEA levels were not found to be of value in predicting the likelihood of subsequent tumor response. Although a general relation between serial CEA measurements and clinical tumor measurements was noted, these measurements were discordant in a substantial proportion of patients. Tumor measurements as an index of response to therapy were strongly correlated with survival, whereas changes in CEA values and patient survival were not correlated at a statistically significant level. Serial CEA measurements were perhaps of some value in predicting progression of malignant disease, and were roughly comparable to serum alkaline phosphatase assay in assessing response of liver metastasis to chemotherapy. Overall, serial CEA measurements added little to the standard clinical assessment of patients with advanced colorectal carcinoma receiving chemotherapy.

Alkaline Phosphatase↗
PubMed1978

Value of preoperative radionuclide bone scan in suspected primary breast carcinoma.

The value of radionuclide bone scanning performed before "curative" surgery in 100 female patients with suspected (91 patients) or known (9 patients) carcinoma of the breast was assessed. Limitations of the bone scan in this patient population were (1) a weak relationship between scan abnormalities and pathologic stage of the primary breast cancer, (2) a high incidence of equivocal scans, and (3) a low incidence of definite scan abnormalities which could not be accounted for by benign osseous disorders. The limited value of preoperative bone scanning in this study may be a result of the high proportion of patients with favorable breast lesions, who would be expected to have a low incidence of bone metastases at the time of primary surgical therapy. Guidelines for the use of bone scanning in the management of primary carcinoma of the breast are discussed.

Adult↗
PubMed1977

Changes in serum high density lipoproteins in women on oral contraceptive drugs.

Serum lipids, lipoproteins, and lipoprotein subfractions were measured in a group of 18 women aged 20 through 39 who were users of oral contraceptive drugs, and in 19 age-matched controls. Concentrations of the major lipid and lipoprotein classes were higher in the users, but the elevation was statistically significant only in the case of the high density lipoproteins. This increase was shown to be due to a highly significant increase (275 +/- 9 vs. 223 +/- 9 mg/100 ml, (p less than 0.005) in the denser high density lipoprotein subfraction (HDL3). Levels of the other subfraction (HDL2) were similar in users and controls. Thus, anovulatory steroids have selective effects on individual types of high density lipoproteins. Studies of such specific effects may help to further define the functional properties of the high density lipoproteins such as their apparent protective role in atherosclerosis.

Adult↗
PubMed1977

A comparison of simplified methods for lipoprotein quantification using the analytic ultracentrifuge as a standard.

Two simplified methods for quantitative lipoprotein analysis have been calibrated and compared with each other using analytic ultracentrifugation as a standard reference procedure. The first method was the Friedewald procedure and the second was an automated agarose gel electrophoresis system. Both procedures offer comparable quantitative lipoprotein analysis with potential for large scale screening purposes at low cost ($4.00-$5.00 per analysis). There were advantages and limitations to both procedures. The Friedwald procedure can be used on frozen sera but requires 3 ml sera. In contrast, the electrophoresis system must be used with fresh serum but requires only 50 mul serum and the electrophoretic slides may be quantitatively analyzed several years retrospectively.

Adult↗
PubMed1969

Derivation of a three compartment model describing disappearance of plasma insulin-131-I in man.

Insulin-(131)I was administered intravenously to normal subjects, to patients with maturity-onset diabetes and normal renal function, and to nondiabetic patients with renal failure. The ensuing plasma disappearance curves of immunoprecipitable radioactive insulin were determined, and these data were analyzed in a variety of ways. Firstly, fractional irreversible loss rates of insulin from plasma were calculated and found to be greatly diminished in patients with renal failure (t((1/2)) = 39 min), as compared with normal (t((1/2)) = 15 min) and diabetic subjects (t((1/2)) = 12 min). Secondly, plasma insulin-(131)I disappearance curves were resolved into sums of three exponentials by the method of "peeling," and values for the resultant three slopes and half-lives were determined. Patients with normal renal function had similar values for all parameters, while those patients with renal failure were differentiated on the basis of the slope of the last component, with a prolongation of its half-life to 275 min (approximately twice normal). Finally, a three pool model was formulated to describe the kinetics of plasma insulin disappearance in man, representing plasma (pool 1), interstitial fluid (pool 2), and all tissues in which insulin is utilized and degraded (pool 3). The proposed model adequately describing the disappearance curves of insulin-(131)I observed in all patients indicated that volumes (per cent body weight) of pool 1 (4.04) and pool 2 (10.11), calculated on the basis of the model and the experimental data, corresponded closely to estimates of plasma and interstitial fluid volumes obtained by independent means. It also demonstrated that patients with renal failure were characterized by a decreased removal rate of insulin from pool 3 and an increased recycling rate of insulin from pool 3 to pool 2. It is concluded that the proposed model represents a reasonable description of the kinetics of insulin distribution and degradation, and that its use provides quantitative insights into the physiology of insulin metabolism.

Diabetes Mellitus↗
PubMed1968

Insulin delivery rate into plasma in normal and diabetic subjects.

Removal of insulin-(131)I from plasma was studied in normal and diabetic subjects with both single injection and continuous infusion of isotope techniques. Patients were studied either in the fasting state or during steady-state hyperglycemia produced by a continuous intravenous glucose infusion. Steady-state plasma insulin concentration during these studies ranged from 10 to 264 muU/ml. Labeled insulin specific activity time curves consisted of more than one exponential, indicating that a multicompartmental system for insulin metabolism exists. A mathematical technique which is applicable to non-first order processes was used to calculate the rate at which insulin was lost irreversibly from the plasma insulin pool. A direct, linear relationship was found between insulin irreversible loss rate and plasma insulin concentration over the range of concentrations studied. This linearity implies lack of saturability of the insulin removal mechanism. Since the plasma insulin pool was in a steady state during these studies, insulin irreversible loss rate was equal to the rate at which newly secreted insulin was being delivered to the general circulation. Therefore, these results indicate that changes in plasma insulin concentration result from parallel changes in the rate of insulin delivery and not from changes in the opposite direction of the rate of insulin removal. A wide range of insulin delivery rates was found among patients with similar plasma glucose concentrations, suggesting that there exists considerable variability in responsiveness to endogenous insulin among these patients.

Adult↗