Search PubMed⌕ Search

Biomedical subjects

A J Hackett

Publications and source records attributed to A J Hackett.

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

Properties of epithelial cells cultured from human carcinomas and nonmalignant tissues.

Human epithelial cell cultures were examined for expression of plasminogen activator and fibronectin matrix. All of the cells examined showed ultrastructural evidence suggesting their epithelial origin, including microvilli and specialized junctions. The nonmalignant cells were also negative for endothelial cell markers (ie. they lacked factor VIII antigen, a nonthrombogenic surface and Weibel-Palade bodies). The nonmalignant lines all produced large amounts of plasminogen activator, whereas the tumor-derived lines showed a gradation of activities, ranging from lines having as much activity as the nonmalignant lines to lines having little or no activity above background. For both normal and malignant cells, addition of dexamethesone only slightly decreased the levels of plasminogen activator. By immunofluorescence microscopy, normal bladder and fetal intestine epithelial cells showed fibronectin in a globular and fibrillar matrix. In contrast, normal mammary epithelial cells had a much diminished amount of fibronectin with a punctate distribution.

Binding Sites↗
PubMed1979

Biological properties of human melanoma cells in culture.

Three human melanoma cell lines derived from one primary and two metastatic tumors from three different patients were characterized for growth properties usually associated with malignant transformation; these include cell morphology, growth rate, saturation density, growth in semisolid media, colony-forming ability on contact-inhibited monolayers of normal fibroblasts and epithelial cells, and tumorigenicity in immunosuppressed mice. Variations in expression of aberrant properties were evident among the lines. One of the metastatic lines satisfied all the parameters of malignancy tested and the other showed a number of these properties, whereas the primary essentially fulfilled only one. These results suggest that cultured melanoma cells reflect the clinical variability often observed among melanoma patients and that metastatic melanoma seems to display a higher degree of malignant transformation than the primary.

Adult↗
PubMed1979

Metabolism of progesterone in the pregnant sheep near term: identification of 3 beta-hydroxy-5 alpha-pregnan-20-one 3-sulfate as a major metabolite.

Two pregnant ewes near term were given a single injection of progesterone-4-14C via the left jugular vein, and serial blood samples were taken from the right jugular vein at 5 min intervals over a period of 40 min. Radioactive steroids in the plasma were separated into unconjugated and conjugated fractions which were further isolated and analysed by established methods. The injected hormone was rapidly metabolized with a half-life of approximately 10 min and metabolic clearance rate about 3.5 liters min. The bulk of the metabolites was found in the sulfate fraction from which a major metabolite was identified as 3 beta-hydroxy-5 alpha-pregnan-20-one. From the unconjugated fraction, 20 alpha-hydroxy-pregn-4-en-3-one, a known minor metabolite was also isolated. No radioactive estrogens were found. It is concluded that a major portion of circulating progesterone in the pregnant ewe near term is cleared by 5 alpha-reduction of ring A, followed by sulfo-conjugation.

Animals↗
PubMed1979

Nuclear ultrastructure of epithelial cell lines derived from human carcinomas and nonmalignant tissues.

The nuclear ultrastructure of sixteen human epithelial cell lines has been characterized in detail by transmission electron microscopy. The cell lines were derived from normal tissues, nonmalignant tissues of cancerous organs, primary carcinomas, and metastatic carcinomas. Every cell section on a grid containing a clearly defined nucleus and nucleolus was scored blindly utilizing a checklist of markers. The goal of these studies was to determine whether any ultrastructural markers consistently distinguished the different stages of malignant progression represented among the lines. Nuclear bodies and perichromatin granules were found in all lines derived from cancer and were not observed in any nonmalignant lines. Nuclear envelope dilation was seen in all lines derived from cancerours organs as well as from malignant tissues but not in any lines derived from normal tissue. Margination of chromatin, irregularity of nuclear outline, redistribution of nucleolar components, and margination were expressed slightly by the normal lines, to variable degrees by the lines derived from cancerous organs, and to a much greater extent by all lines derived from malignant tissues. No differences were found between lines derived from primary carcinomas and those derived from metastatic specimens. There were no ultrastructural differences comparing subconfluent and confluent cells or cells at different passage levels. In addition, the nuclear ultrastructure of a malignant line in culture was similar to that of a tumor induced by those cells in an immunosuppressed mouse.

Cell Division↗
PubMed1977

Two syngeneic cell lines from human breast tissue: the aneuploid mammary epithelial (Hs578T) and the diploid myoepithelial (Hs578Bst) cell lines.

We characterized two human cell lines (Hs578T and Hs578Bst), which provide several unique features that should be useful in the study of breast disease. Hs578T, derived from a carcinosarcoma, is epithelial in origin. Hs578Bst, established from normal tissue peripheral to the tumor, is myoepithelial in origin. This is the first report of companion cell lines, one malignant and one normal, established from the same organ.

Aneuploidy↗
PubMed1977

Voluntary isometric muscle strength of patients undergoing rehabilitation following fractures of the lower limb.

Isometric muscle strength was measured in 32 servicemen recovering from fractures of the lower limb. At the time when patients were admitted for rehabilitation there were marked reductions of strength in the injured limb of muscles acting at the hip, knee and ankle joints. Marked improvement of strength occurred during rehabilitation, but there were still significant differences between the limbs at the time of discharge from the rehabilitation unit.

Ankle Joint↗
PubMed1976

Alteration of the cell membrane architecture during suspension and monolayer culturing.

Using suspension-growth-adapted HeLa (S3) cells, we followed the alterations in cell morphology during attachment and spreading on a glass surface in vitro by scanning electron microscopy. Suspension cultivation obviated the need for trypsinization or EDTA treatment of the cells before seeding, thus the cell surface was not chemically altered. The suspension-grown cells were sperical and covered with microvilli. Three hours after seeding into stationary culture, attached cells had surface blebs and large processes, but no microvilli. During the following 9 h, the surface topography altered stepwise producing a complex lamelloplasm. The paper discusses how these membrane events are related to the cell cycle and metastasis.

Cell Membrane↗
PubMed1976

Physiological performance and work capacity of Sudanese cane cutters with Schistosoma mansoni infection.

Physiological tests of work performance and measurement of field productivity were made in 194 Sudanese cane cutters in order to study the effect of Schistosoma mansoni infection. The cane cutters were selected from two age ranges (16-24 and 25-45 years) and subdivided into three clinical groups: not infected, infected with, and infected without clinical signs of hepatosplenomegaly. Men infected with Schistosoma haemotobium, malaria (blood film), or with hemoglobin levels less than 10 g/100 ml were excluded. There was a statistically significant (P less than 0.002) higher mean hemoglobin concentration in those not infected but the mean difference was less than 1 g/100 ml. Submaximal responses to exercise on a stationary bicycle ergometer, oxygen intake, ventilation, tidal volume, cardiac frequency and estimated maximal aerobic power output calculated both in absolute terms and relative to lean body mass and leg volume were similar in the six groups of cane cutters. No significant differences were found in physique, body composition or in thermoregulatory function tests. The cane cutters were found to have little natural acclimatization to heat in terms of sweating capacity when compared with a group of fully acclimatized Sudanese soldiers. The mean productivity (mean daily weight of cane cut per man) was significantly correlated with the individual's estimated maximum aerobic capacity determined in the laboratory, but not with the degree of S. mansoni infection. The noninfected group was less "efficient" (mean productivity:oxygen intake) during cutting than the infected groups but a larger proportion of the noninfected were in their first season of cutting. There was a positive correlation between the number of seasons' cutting experience and the individual's age, degree of infection and mean productivity. Cane cutters studied in this investigation were a relatively fit, active population from whom the more seriously ill were excluded. These results do not, therefore necessarily reflect the effects of S. mansoni on physiological work capacity and productivity of more static populations in areas of high endemicity.

Adolescent↗
PubMed1975

Studies on morphological transformation of BALB/3T3-derived clones by murine leukemia virus.

We have described a cell line, UC1-B, derived spontaneously from BALB/3T3 mouse embryo cells, which, unlike the standard BALB/3T3, are morphologically transformed and produce bizarre viral forms in response to murine leukemia virus. Although UC1-B and BALB/3T3 are morphologically similar, and both form contact-inhibited monolayers at confluence, the UC1-B cells are partially transformed because: they grow to a slightly higher saturation density than 3T3 cells, they grow in medium lacking serum growth factors, and they produce tumors in mice. Another clone, 12A-3, derived from BALB/3T3, also transforms and produces bizarre viral forms after infection with murine leukemia virus. Unlike UC1-B cells, the 12A3-8 cells are identical in growth properties to BALB/3T3; therefore, a partially altered morphology is not required for the induction of transformation by murine leukemia virus.

Animals↗
PubMed1975

Osteogenic sarcoma. Immunologic parameters before and during immunotherapy with tumor-specific transfer factor.

18 patients with osteogenic sarcoma were followed by serial measurements in vitro of tumor-specific cell-mediated cytotoxicity and of "active" and total rosette-forming T-cells. 13 of these patients have had or are currently receiving injections of osteogenic sarcoma-specific dialyzable transfer factor derived from healthy donors. In three patients with very small lesions, cytotoxicity was high before amputation and decreased within 2 mo after removal of tumor. Cytotoxicity was low at time of diagnosis in all patients with large tumor masses. The cytotoxicity of the patients' lymphocytes increased after administration of tumor-specific transfer factor in all patients so treated. Patients receiving nonspecific transfer factor showed evidence of declining cell-mediated cytotoxicity. Tumor-specific transfer factor may produce an increase in cell-mediated cytotoxicity to the tumor in patients with osteogenic sarcoma. This possibility is suggested by the pain and edema that occurred in the area of the tumor in patients who had metastatic disease when therapy was started and by lymphocytic infiltrates in the tumor, as well as by the increase in cell-mediated cytotoxicity and the increase in percentage of active rosette-forming cells from subnormal to normal. Serial measurements of cell-mediated cytotoxicity are helpful in monitoring the efficacy of transfer factor and other modes of therapy in these patients, and these measurements are the best available criteria for selection of donors of tumor-specific transfer factor.

Adenocarcinoma↗
PubMed1975

Tumor-specific cell-mediated immunity in household contacts of cancer patients..

Patients with osteogenic sarcoma (and related tumors), hypernephroma, and breast carcinoma, and their household contacts were tested for tumor-specific cell-mediated immunity against these tumors with the use of a short-term chromium-51 release assay. This assay, reproducible over many months and well-correlated with the clinical course of the patients, was used to demonstrate that household contacts of patients with osteogenic sarcoma and breast carcinoma have specific immunity against the tumor type with which they have been in contact. In both types of tumors, the range of cytotoxicity values produced by lymphocytes from the household contacts was significantly higher than that of the normal population. The incidence of immunity was much higher in household contacts of patients with breast carcinoma than in those of patients with osteogenic sarcoma. Immunity was found with equal frequency in men and women, as well as in genetically and nongenetically related household contacts (guardians, adopted children, spouses). Immunity against hypernephroma was not demonstrated in either patients with hypernephroma or their household contacts.

Adenocarcinoma↗
PubMed1975

Quantitative immunofluorescence studies of the tumor antigen-bearing cell in giant cell tumor of bone and osteogenic sarcoma.

Tumor-associated antigen was found by reacting sera from two patients with giant cell tumor of bone with cells derived from their tumors, using autologous serum as intermediate reactant and fluorescein-conjugated goat anti-human IgG as final reactant. Approximately 40% of the plump, spindle-shaped cells that formed the background stroma of these tumors possessed the antigen; however, it was not present on giant cells. Fluorescence was much greater than that on similarly stained cells from 4 osteogenic sarcomas, suggesting that the antigenic density on cells from giant cell tumor was greater than that on cells from osteogenic sarcoma. Antibodies in sera from giant cell tumor patients and osteogenic sarcoma patients showed specific cross-reactivity. Stromal cells of giant cell tumors were established in culture and retained tumor-associated antigen, whereas giant cells failed to divide and detached from the flask within two weeks. Intensity of fluorescence (antigenic density) decreased with progressive passage levels, but a larger percentage of cells showed fluorescence. At the tenth passage, all cells bore tumor-associated antigen. Cultured cells that were injected s.c. into mice formed progressively growing nodules, the cells of which were morphologically indistinguishable from stromal cells of the original tumor; all cells retained tumor-associated antigen, but antigenic density had decreased to about one-seventh of the value found originally. No giant cells were present in the nodules.

Animals↗